* ext/psych/*: importing Psych to trunk

* test/psych/*: ditto * lib/psych/*: ditto git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@27079 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2022-11-09 12:17:21 -05:00 · 2010-03-28 21:49:37 +00:00 · 2010-03-28 21:49:37 +00:00 · b9b923ca94
commit b9b923ca94
parent a8a99a7379
66 changed files with 6056 additions and 0 deletions
--- a/6
+++ b/6
@ -1,3 +1,9 @@
+Mon Mar 29 06:47:25 2010  Aaron Patterson <aaron@tenderlovemaking.com>
+
+	* ext/psych/*: importing Psych to trunk
+	* test/psych/*: ditto
+	* lib/psych/*: ditto
+
 Sun Mar 28 21:04:21 2010  NARUSE, Yui  <naruse@ruby-lang.org>

 	* configure.in (ac_cv_func_snprintf, ac_cv_func_vsnprintf):
--- a/ext/psych/emitter.c
+++ b/ext/psych/emitter.c
@ -0,0 +1,413 @@
+#include <psych.h>
+
+VALUE cPsychEmitter;
+static ID id_write;
+
+static void emit(yaml_emitter_t * emitter, yaml_event_t * event)
+{
+    if(!yaml_emitter_emit(emitter, event))
+	rb_raise(rb_eRuntimeError, "%s", emitter->problem);
+}
+
+static int writer(void *ctx, unsigned char *buffer, size_t size)
+{
+    VALUE io = (VALUE)ctx;
+    VALUE str = rb_str_new((const char *)buffer, (long)size);
+    VALUE wrote = rb_funcall(io, id_write, 1, str);
+    return (int)NUM2INT(wrote);
+}
+
+static void dealloc(yaml_emitter_t * emitter)
+{
+    yaml_emitter_delete(emitter);
+    free(emitter);
+}
+
+static VALUE allocate(VALUE klass)
+{
+    yaml_emitter_t * emitter = malloc(sizeof(yaml_emitter_t));
+    yaml_emitter_initialize(emitter);
+    yaml_emitter_set_unicode(emitter, 1);
+    yaml_emitter_set_indent(emitter, 2);
+
+    return Data_Wrap_Struct(klass, 0, dealloc, emitter);
+}
+
+/* call-seq: Psych::Emitter.new(io)
+ *
+ * Create a new Psych::Emitter that writes to +io+.
+ */
+static VALUE initialize(VALUE self, VALUE io)
+{
+    yaml_emitter_t * emitter;
+    Data_Get_Struct(self, yaml_emitter_t, emitter);
+
+    yaml_emitter_set_output(emitter, writer, (void *)io);
+
+    return self;
+}
+
+/* call-seq: emitter.start_stream(encoding)
+ *
+ * Start a stream emission with +encoding+
+ *
+ * See Psych::Handler#start_stream
+ */
+static VALUE start_stream(VALUE self, VALUE encoding)
+{
+    yaml_emitter_t * emitter;
+    Data_Get_Struct(self, yaml_emitter_t, emitter);
+    Check_Type(encoding, T_FIXNUM);
+
+    yaml_event_t event;
+    yaml_stream_start_event_initialize(&event, (yaml_encoding_t)NUM2INT(encoding));
+
+    emit(emitter, &event);
+
+    return self;
+}
+
+/* call-seq: emitter.end_stream
+ *
+ * End a stream emission
+ *
+ * See Psych::Handler#end_stream
+ */
+static VALUE end_stream(VALUE self)
+{
+    yaml_emitter_t * emitter;
+    Data_Get_Struct(self, yaml_emitter_t, emitter);
+
+    yaml_event_t event;
+    yaml_stream_end_event_initialize(&event);
+
+    emit(emitter, &event);
+
+    return self;
+}
+
+/* call-seq: emitter.start_document(version, tags, implicit)
+ *
+ * Start a document emission with YAML +version+, +tags+, and an +implicit+
+ * start.
+ *
+ * See Psych::Handler#start_document
+ */
+static VALUE start_document(VALUE self, VALUE version, VALUE tags, VALUE imp)
+{
+    yaml_emitter_t * emitter;
+    Data_Get_Struct(self, yaml_emitter_t, emitter);
+
+    yaml_version_directive_t version_directive;
+
+    Check_Type(version, T_ARRAY);
+
+    if(RARRAY_LEN(version) > 0) {
+	VALUE major = rb_ary_entry(version, (long)0);
+	VALUE minor = rb_ary_entry(version, (long)1);
+
+	version_directive.major = NUM2INT(major);
+	version_directive.minor = NUM2INT(minor);
+    }
+
+    yaml_tag_directive_t * head = NULL;
+    yaml_tag_directive_t * tail = NULL;
+
+    if(RTEST(tags)) {
+	int i = 0;
+
+	Check_Type(tags, T_ARRAY);
+
+	head  = xcalloc((size_t)RARRAY_LEN(tags), sizeof(yaml_tag_directive_t));
+	tail  = head;
+
+	for(i = 0; i < RARRAY_LEN(tags); i++) {
+	    VALUE tuple = RARRAY_PTR(tags)[i];
+	    Check_Type(tuple, T_ARRAY);
+
+	    if(RARRAY_LEN(tuple) < 2) {
+		xfree(head);
+		rb_raise(rb_eRuntimeError, "tag tuple must be of length 2");
+	    }
+
+	    tail->handle = (yaml_char_t *)StringValuePtr(RARRAY_PTR(tuple)[0]);
+	    tail->prefix = (yaml_char_t *)StringValuePtr(RARRAY_PTR(tuple)[1]);
+
+	    tail++;
+	}
+    }
+
+    yaml_event_t event;
+    yaml_document_start_event_initialize(
+	    &event,
+	    (RARRAY_LEN(version) > 0) ? &version_directive : NULL,
+	    head,
+	    tail,
+	    imp ? 1 : 0
+	    );
+
+    emit(emitter, &event);
+
+    if(head) xfree(head);
+
+    return self;
+}
+
+/* call-seq: emitter.end_document(implicit)
+ *
+ * End a document emission with an +implicit+ ending.
+ *
+ * See Psych::Handler#end_document
+ */
+static VALUE end_document(VALUE self, VALUE imp)
+{
+    yaml_emitter_t * emitter;
+    Data_Get_Struct(self, yaml_emitter_t, emitter);
+
+    yaml_event_t event;
+    yaml_document_end_event_initialize(&event, imp ? 1 : 0);
+
+    emit(emitter, &event);
+
+    return self;
+}
+
+/* call-seq: emitter.scalar(value, anchor, tag, plain, quoted, style)
+ *
+ * Emit a scalar with +value+, +anchor+, +tag+, and a +plain+ or +quoted+
+ * string type with +style+.
+ *
+ * See Psych::Handler#scalar
+ */
+static VALUE scalar(
+	VALUE self,
+	VALUE value,
+	VALUE anchor,
+	VALUE tag,
+	VALUE plain,
+	VALUE quoted,
+	VALUE style
+	) {
+    yaml_emitter_t * emitter;
+    Data_Get_Struct(self, yaml_emitter_t, emitter);
+
+    Check_Type(value, T_STRING);
+
+    yaml_event_t event;
+    yaml_scalar_event_initialize(
+	    &event,
+	    (yaml_char_t *)(NIL_P(anchor) ? NULL : StringValuePtr(anchor)),
+	    (yaml_char_t *)(NIL_P(tag) ? NULL : StringValuePtr(tag)),
+	    (yaml_char_t*)StringValuePtr(value),
+	    (int)RSTRING_LEN(value),
+	    plain ? 1 : 0,
+	    quoted ? 1 : 0,
+	    (yaml_scalar_style_t)NUM2INT(style)
+	    );
+
+    emit(emitter, &event);
+
+    return self;
+}
+
+/* call-seq: emitter.start_sequence(anchor, tag, implicit, style)
+ *
+ * Start emitting a sequence with +anchor+, a +tag+, +implicit+ sequence
+ * start and end, along with +style+.
+ *
+ * See Psych::Handler#start_sequence
+ */
+static VALUE start_sequence(
+	VALUE self,
+	VALUE anchor,
+	VALUE tag,
+	VALUE implicit,
+	VALUE style
+	) {
+    yaml_emitter_t * emitter;
+    Data_Get_Struct(self, yaml_emitter_t, emitter);
+
+    yaml_event_t event;
+    yaml_sequence_start_event_initialize(
+	    &event,
+	    (yaml_char_t *)(NIL_P(anchor) ? NULL : StringValuePtr(anchor)),
+	    (yaml_char_t *)(NIL_P(tag) ? NULL : StringValuePtr(tag)),
+	    implicit ? 1 : 0,
+	    (yaml_sequence_style_t)NUM2INT(style)
+	    );
+
+    emit(emitter, &event);
+
+    return self;
+}
+
+/* call-seq: emitter.end_sequence
+ *
+ * End sequence emission.
+ *
+ * See Psych::Handler#end_sequence
+ */
+static VALUE end_sequence(VALUE self)
+{
+    yaml_emitter_t * emitter;
+    Data_Get_Struct(self, yaml_emitter_t, emitter);
+
+    yaml_event_t event;
+    yaml_sequence_end_event_initialize(&event);
+
+    emit(emitter, &event);
+
+    return self;
+}
+
+/* call-seq: emitter.start_mapping(anchor, tag, implicit, style)
+ *
+ * Start emitting a YAML map with +anchor+, +tag+, an +implicit+ start
+ * and end, and +style+.
+ *
+ * See Psych::Handler#start_mapping
+ */
+static VALUE start_mapping(
+	VALUE self,
+	VALUE anchor,
+	VALUE tag,
+	VALUE implicit,
+	VALUE style
+	) {
+    yaml_emitter_t * emitter;
+    Data_Get_Struct(self, yaml_emitter_t, emitter);
+
+    yaml_event_t event;
+    yaml_mapping_start_event_initialize(
+	    &event,
+	    (yaml_char_t *)(NIL_P(anchor) ? NULL : StringValuePtr(anchor)),
+	    (yaml_char_t *)(NIL_P(tag) ? NULL : StringValuePtr(tag)),
+	    implicit ? 1 : 0,
+	    (yaml_sequence_style_t)NUM2INT(style)
+	    );
+
+    emit(emitter, &event);
+
+    return self;
+}
+
+/* call-seq: emitter.end_mapping
+ *
+ * Emit the end of a mapping.
+ *
+ * See Psych::Handler#end_mapping
+ */
+static VALUE end_mapping(VALUE self)
+{
+    yaml_emitter_t * emitter;
+    Data_Get_Struct(self, yaml_emitter_t, emitter);
+
+    yaml_event_t event;
+    yaml_mapping_end_event_initialize(&event);
+
+    emit(emitter, &event);
+
+    return self;
+}
+
+/* call-seq: emitter.alias(anchor)
+ *
+ * Emit an alias with +anchor+.
+ *
+ * See Psych::Handler#alias
+ */
+static VALUE alias(VALUE self, VALUE anchor)
+{
+    yaml_emitter_t * emitter;
+    Data_Get_Struct(self, yaml_emitter_t, emitter);
+
+    yaml_event_t event;
+    yaml_alias_event_initialize(
+	    &event,
+	    (yaml_char_t *)(NIL_P(anchor) ? NULL : StringValuePtr(anchor))
+	    );
+
+    emit(emitter, &event);
+
+    return self;
+}
+
+/* call-seq: emitter.canonical = true
+ *
+ * Set the output style to canonical, or not.
+ */
+static VALUE set_canonical(VALUE self, VALUE style)
+{
+    yaml_emitter_t * emitter;
+    Data_Get_Struct(self, yaml_emitter_t, emitter);
+
+    yaml_emitter_set_canonical(emitter, Qtrue == style ? 1 : 0);
+
+    return style;
+}
+
+/* call-seq: emitter.canonical
+ *
+ * Get the output style, canonical or not.
+ */
+static VALUE canonical(VALUE self)
+{
+    yaml_emitter_t * emitter;
+    Data_Get_Struct(self, yaml_emitter_t, emitter);
+
+    return (emitter->canonical == 0) ? Qfalse : Qtrue;
+}
+
+/* call-seq: emitter.indentation = level
+ *
+ * Set the indentation level to +level+.
+ */
+static VALUE set_indentation(VALUE self, VALUE level)
+{
+    yaml_emitter_t * emitter;
+    Data_Get_Struct(self, yaml_emitter_t, emitter);
+
+    yaml_emitter_set_indent(emitter, NUM2INT(level));
+
+    return level;
+}
+
+/* call-seq: emitter.indentation
+ *
+ * Get the indentation level.
+ */
+static VALUE indentation(VALUE self)
+{
+    yaml_emitter_t * emitter;
+    Data_Get_Struct(self, yaml_emitter_t, emitter);
+
+    return INT2NUM(emitter->best_indent);
+}
+
+void Init_psych_emitter()
+{
+    VALUE psych     = rb_define_module("Psych");
+    VALUE handler   = rb_define_class_under(psych, "Handler", rb_cObject);
+    cPsychEmitter   = rb_define_class_under(psych, "Emitter", handler);
+
+    rb_define_alloc_func(cPsychEmitter, allocate);
+
+    rb_define_method(cPsychEmitter, "initialize", initialize, 1);
+    rb_define_method(cPsychEmitter, "start_stream", start_stream, 1);
+    rb_define_method(cPsychEmitter, "end_stream", end_stream, 0);
+    rb_define_method(cPsychEmitter, "start_document", start_document, 3);
+    rb_define_method(cPsychEmitter, "end_document", end_document, 1);
+    rb_define_method(cPsychEmitter, "scalar", scalar, 6);
+    rb_define_method(cPsychEmitter, "start_sequence", start_sequence, 4);
+    rb_define_method(cPsychEmitter, "end_sequence", end_sequence, 0);
+    rb_define_method(cPsychEmitter, "start_mapping", start_mapping, 4);
+    rb_define_method(cPsychEmitter, "end_mapping", end_mapping, 0);
+    rb_define_method(cPsychEmitter, "alias", alias, 1);
+    rb_define_method(cPsychEmitter, "canonical", canonical, 0);
+    rb_define_method(cPsychEmitter, "canonical=", set_canonical, 1);
+    rb_define_method(cPsychEmitter, "indentation", indentation, 0);
+    rb_define_method(cPsychEmitter, "indentation=", set_indentation, 1);
+
+    id_write = rb_intern("write");
+}
+/* vim: set noet sws=4 sw=4: */
--- a/ext/psych/emitter.h
+++ b/ext/psych/emitter.h
@ -0,0 +1,8 @@
+#ifndef PSYCH_EMITTER_H
+#define PSYCH_EMITTER_H
+
+#include <psych.h>
+
+void Init_psych_emitter();
+
+#endif
--- a/ext/psych/extconf.rb
+++ b/ext/psych/extconf.rb
@ -0,0 +1,22 @@
+require 'mkmf'
+
+# :stopdoc:
+
+RbConfig::MAKEFILE_CONFIG['CC'] = ENV['CC'] if ENV['CC']
+
+INCLUDEDIR = Config::CONFIG['includedir']
+LIBDIR     = Config::CONFIG['libdir']
+LIB_DIRS   = ['/opt/local/lib', '/usr/local/lib', LIBDIR, '/usr/lib']
+libyaml    = dir_config 'libyaml', '/opt/local/include', '/opt/local/lib'
+
+def asplode missing
+  abort "#{missing} is missing. Try 'port install libyaml +universal' " +
+        "or 'yum install libyaml-devel'"
+end
+
+asplode('yaml.h')  unless find_header  'yaml.h'
+asplode('libyaml') unless find_library 'yaml', 'yaml_get_version'
+
+create_makefile 'psych/psych'
+
+# :startdoc:
--- a/ext/psych/parser.c
+++ b/ext/psych/parser.c
@ -0,0 +1,314 @@
+#include <psych.h>
+
+VALUE cPsychParser;
+VALUE ePsychSyntaxError;
+
+static ID id_read;
+static ID id_empty;
+static ID id_start_stream;
+static ID id_end_stream;
+static ID id_start_document;
+static ID id_end_document;
+static ID id_alias;
+static ID id_scalar;
+static ID id_start_sequence;
+static ID id_end_sequence;
+static ID id_start_mapping;
+static ID id_end_mapping;
+
+static int io_reader(void * data, unsigned char *buf, size_t size, size_t *read)
+{
+    VALUE io = (VALUE)data;
+    VALUE string = rb_funcall(io, id_read, 1, INT2NUM(size));
+
+    *read = 0;
+
+    if(! NIL_P(string)) {
+	void * str = (void *)StringValuePtr(string);
+	*read = (size_t)RSTRING_LEN(string);
+	memcpy(buf, str, *read);
+    }
+
+    return 1;
+}
+
+/*
+ * call-seq:
+ *    parser.parse(yaml)
+ *
+ * Parse the YAML document contained in +yaml+.  Events will be called on
+ * the handler set on the parser instance.
+ *
+ * See Psych::Parser and Psych::Parser#handler
+ */
+static VALUE parse(VALUE self, VALUE yaml)
+{
+    yaml_parser_t parser;
+    yaml_event_t event;
+
+    yaml_parser_initialize(&parser);
+
+    if(rb_respond_to(yaml, id_read)) {
+	yaml_parser_set_input(&parser, io_reader, (void *)yaml);
+    } else {
+	yaml_parser_set_input_string(
+		&parser,
+		(const unsigned char *)StringValuePtr(yaml),
+		(size_t)RSTRING_LEN(yaml)
+		);
+    }
+
+    int done = 0;
+#ifdef HAVE_RUBY_ENCODING_H
+    int encoding = rb_enc_find_index("ASCII-8BIT");
+#endif
+
+    VALUE handler = rb_iv_get(self, "@handler");
+
+    while(!done) {
+	if(!yaml_parser_parse(&parser, &event)) {
+	    size_t line   = parser.mark.line;
+	    size_t column = parser.mark.column;
+
+	    yaml_parser_delete(&parser);
+	    rb_raise(ePsychSyntaxError, "couldn't parse YAML at line %d column %d",
+		    (int)line, (int)column);
+	}
+
+	switch(event.type) {
+	    case YAML_STREAM_START_EVENT:
+
+#ifdef HAVE_RUBY_ENCODING_H
+		switch(event.data.stream_start.encoding) {
+		    case YAML_ANY_ENCODING:
+			break;
+		    case YAML_UTF8_ENCODING:
+			encoding = rb_enc_find_index("UTF-8");
+			break;
+		    case YAML_UTF16LE_ENCODING:
+			encoding = rb_enc_find_index("UTF-16LE");
+			break;
+		    case YAML_UTF16BE_ENCODING:
+			encoding = rb_enc_find_index("UTF-16BE");
+			break;
+		    default:
+			break;
+		}
+#endif
+
+		rb_funcall(handler, id_start_stream, 1,
+			INT2NUM((long)event.data.stream_start.encoding)
+	      );
+		break;
+	    case YAML_DOCUMENT_START_EVENT:
+		{
+	// Grab the document version
+	VALUE version = event.data.document_start.version_directive ?
+	    rb_ary_new3(
+		    (long)2,
+		    INT2NUM((long)event.data.document_start.version_directive->major),
+		    INT2NUM((long)event.data.document_start.version_directive->minor)
+		 ) : rb_ary_new();
+
+	// Get a list of tag directives (if any)
+	VALUE tag_directives = rb_ary_new();
+	if(event.data.document_start.tag_directives.start) {
+	    yaml_tag_directive_t *start =
+		event.data.document_start.tag_directives.start;
+	    yaml_tag_directive_t *end =
+		event.data.document_start.tag_directives.end;
+	    for(; start != end; start++) {
+		VALUE handle = Qnil;
+		if(start->handle) {
+		    handle = rb_str_new2((const char *)start->handle);
+#ifdef HAVE_RUBY_ENCODING_H
+		    rb_enc_associate_index(handle, encoding);
+#endif
+		}
+
+		VALUE prefix = Qnil;
+		if(start->prefix) {
+		    prefix = rb_str_new2((const char *)start->prefix);
+#ifdef HAVE_RUBY_ENCODING_H
+		    rb_enc_associate_index(prefix, encoding);
+#endif
+		}
+
+		VALUE pair = rb_ary_new3((long)2, handle, prefix);
+		rb_ary_push(tag_directives, pair);
+	    }
+	}
+	rb_funcall(handler, id_start_document, 3,
+		version, tag_directives,
+		event.data.document_start.implicit == 1 ? Qtrue : Qfalse
+	    );
+    }
+		break;
+	    case YAML_DOCUMENT_END_EVENT:
+		rb_funcall(handler, id_end_document, 1,
+			event.data.document_end.implicit == 1 ? Qtrue : Qfalse
+	      );
+		break;
+	    case YAML_ALIAS_EVENT:
+		{
+	VALUE alias = Qnil;
+	if(event.data.alias.anchor) {
+	    alias = rb_str_new2((const char *)event.data.alias.anchor);
+#ifdef HAVE_RUBY_ENCODING_H
+	    rb_enc_associate_index(alias, encoding);
+#endif
+	}
+
+	rb_funcall(handler, id_alias, 1, alias);
+    }
+		break;
+	    case YAML_SCALAR_EVENT:
+		{
+	VALUE val = rb_str_new(
+		(const char *)event.data.scalar.value,
+		(long)event.data.scalar.length
+		);
+
+#ifdef HAVE_RUBY_ENCODING_H
+	rb_enc_associate_index(val, encoding);
+#endif
+
+	VALUE anchor = Qnil;
+	if(event.data.scalar.anchor) {
+	    anchor = rb_str_new2((const char *)event.data.scalar.anchor);
+#ifdef HAVE_RUBY_ENCODING_H
+	    rb_enc_associate_index(anchor, encoding);
+#endif
+	}
+
+	VALUE tag = Qnil;
+	if(event.data.scalar.tag) {
+	    tag = rb_str_new2((const char *)event.data.scalar.tag);
+#ifdef HAVE_RUBY_ENCODING_H
+	    rb_enc_associate_index(tag, encoding);
+#endif
+	}
+
+	VALUE plain_implicit =
+	    event.data.scalar.plain_implicit == 0 ? Qfalse : Qtrue;
+
+	VALUE quoted_implicit =
+	    event.data.scalar.quoted_implicit == 0 ? Qfalse : Qtrue;
+
+	VALUE style = INT2NUM((long)event.data.scalar.style);
+
+	rb_funcall(handler, id_scalar, 6,
+		val, anchor, tag, plain_implicit, quoted_implicit, style);
+    }
+		break;
+	    case YAML_SEQUENCE_START_EVENT:
+		{
+	VALUE anchor = Qnil;
+	if(event.data.sequence_start.anchor) {
+	    anchor = rb_str_new2((const char *)event.data.sequence_start.anchor);
+#ifdef HAVE_RUBY_ENCODING_H
+	    rb_enc_associate_index(anchor, encoding);
+#endif
+	}
+
+	VALUE tag = Qnil;
+	if(event.data.sequence_start.tag) {
+	    tag = rb_str_new2((const char *)event.data.sequence_start.tag);
+#ifdef HAVE_RUBY_ENCODING_H
+	    rb_enc_associate_index(tag, encoding);
+#endif
+	}
+
+	VALUE implicit =
+	    event.data.sequence_start.implicit == 0 ? Qfalse : Qtrue;
+
+	VALUE style = INT2NUM((long)event.data.sequence_start.style);
+
+	rb_funcall(handler, id_start_sequence, 4,
+		anchor, tag, implicit, style);
+    }
+		break;
+	    case YAML_SEQUENCE_END_EVENT:
+		rb_funcall(handler, id_end_sequence, 0);
+		break;
+	    case YAML_MAPPING_START_EVENT:
+		{
+	VALUE anchor = Qnil;
+	if(event.data.mapping_start.anchor) {
+	    anchor = rb_str_new2((const char *)event.data.mapping_start.anchor);
+#ifdef HAVE_RUBY_ENCODING_H
+	    rb_enc_associate_index(anchor, encoding);
+#endif
+	}
+
+	VALUE tag = Qnil;
+	if(event.data.mapping_start.tag) {
+	    tag = rb_str_new2((const char *)event.data.mapping_start.tag);
+#ifdef HAVE_RUBY_ENCODING_H
+	    rb_enc_associate_index(tag, encoding);
+#endif
+	}
+
+	VALUE implicit =
+	    event.data.mapping_start.implicit == 0 ? Qfalse : Qtrue;
+
+	VALUE style = INT2NUM((long)event.data.mapping_start.style);
+
+	rb_funcall(handler, id_start_mapping, 4,
+		anchor, tag, implicit, style);
+    }
+		break;
+	    case YAML_MAPPING_END_EVENT:
+		rb_funcall(handler, id_end_mapping, 0);
+		break;
+	    case YAML_NO_EVENT:
+		rb_funcall(handler, id_empty, 0);
+		break;
+	    case YAML_STREAM_END_EVENT:
+		rb_funcall(handler, id_end_stream, 0);
+		done = 1;
+		break;
+	}
+    }
+
+    return self;
+}
+
+void Init_psych_parser()
+{
+#if 0
+    mPsych = rb_define_module("Psych");
+#endif
+
+    cPsychParser = rb_define_class_under(mPsych, "Parser", rb_cObject);
+
+    /* Any encoding: Let the parser choose the encoding */
+    rb_define_const(cPsychParser, "ANY", INT2NUM(YAML_ANY_ENCODING));
+
+    /* UTF-8 Encoding */
+    rb_define_const(cPsychParser, "UTF8", INT2NUM(YAML_UTF8_ENCODING));
+
+    /* UTF-16-LE Encoding with BOM */
+    rb_define_const(cPsychParser, "UTF16LE", INT2NUM(YAML_UTF16LE_ENCODING));
+
+    /* UTF-16-BE Encoding with BOM */
+    rb_define_const(cPsychParser, "UTF16BE", INT2NUM(YAML_UTF16BE_ENCODING));
+
+    ePsychSyntaxError = rb_define_class_under(mPsych, "SyntaxError", rb_eSyntaxError);
+
+    rb_define_method(cPsychParser, "parse", parse, 1);
+
+    id_read           = rb_intern("read");
+    id_empty          = rb_intern("empty");
+    id_start_stream   = rb_intern("start_stream");
+    id_end_stream     = rb_intern("end_stream");
+    id_start_document = rb_intern("start_document");
+    id_end_document   = rb_intern("end_document");
+    id_alias          = rb_intern("alias");
+    id_scalar         = rb_intern("scalar");
+    id_start_sequence = rb_intern("start_sequence");
+    id_end_sequence   = rb_intern("end_sequence");
+    id_start_mapping  = rb_intern("start_mapping");
+    id_end_mapping    = rb_intern("end_mapping");
+}
+/* vim: set noet sws=4 sw=4: */
--- a/ext/psych/parser.h
+++ b/ext/psych/parser.h
@ -0,0 +1,6 @@
+#ifndef PSYCH_PARSER_H
+#define PSYCH_PARSER_H
+
+void Init_psych_parser();
+
+#endif
--- a/ext/psych/psych.c
+++ b/ext/psych/psych.c
@ -0,0 +1,35 @@
+#include <psych.h>
+
+/* call-seq: Psych.libyaml_version
+ *
+ * Returns the version of libyaml being used
+ */
+static VALUE libyaml_version(VALUE module)
+{
+    int major, minor, patch;
+
+    yaml_get_version(&major, &minor, &patch);
+
+    VALUE list[3] = {
+	INT2NUM((long)major),
+	INT2NUM((long)minor),
+	INT2NUM((long)patch)
+    };
+
+    return rb_ary_new4((long)3, list);
+}
+
+VALUE mPsych;
+
+void Init_psych()
+{
+    mPsych = rb_define_module("Psych");
+
+    rb_define_singleton_method(mPsych, "libyaml_version", libyaml_version, 0);
+
+    Init_psych_parser();
+    Init_psych_emitter();
+    Init_psych_to_ruby();
+    Init_psych_yaml_tree();
+}
+/* vim: set noet sws=4 sw=4: */
--- a/ext/psych/psych.h
+++ b/ext/psych/psych.h
@ -0,0 +1,20 @@
+#ifndef PSYCH_H
+#define PSYCH_H
+
+#include <ruby.h>
+
+#ifdef HAVE_RUBY_ENCODING_H
+#include <ruby/encoding.h>
+#endif
+
+#include <yaml.h>
+
+#include <parser.h>
+#include <emitter.h>
+#include <to_ruby.h>
+#include <yaml_tree.h>
+
+extern VALUE mPsych;
+
+
+#endif
--- a/ext/psych/to_ruby.c
+++ b/ext/psych/to_ruby.c
@ -0,0 +1,41 @@
+#include <psych.h>
+
+VALUE cPsychVisitorsToRuby;
+
+/* call-seq: vis.build_exception(klass, message)
+ *
+ * Create an exception with class +klass+ and +message+
+ */
+static VALUE build_exception(VALUE self, VALUE klass, VALUE mesg)
+{
+    VALUE e = rb_obj_alloc(klass);
+
+    rb_iv_set(e, "mesg", mesg);
+
+    return e;
+}
+
+/* call-seq: vis.path2class(path)
+ *
+ * Convert +path+ string to a class
+ */
+static VALUE path2class(VALUE self, VALUE path)
+{
+#ifdef HAVE_RUBY_ENCODING_H
+    return rb_path_to_class(path);
+#else
+    return rb_path2class(StringValuePtr(path));
+#endif
+}
+
+void Init_psych_to_ruby(void)
+{
+    VALUE psych     = rb_define_module("Psych");
+    VALUE visitors  = rb_define_module_under(psych, "Visitors");
+    VALUE visitor   = rb_define_class_under(visitors, "Visitor", rb_cObject);
+    cPsychVisitorsToRuby = rb_define_class_under(visitors, "ToRuby", visitor);
+
+    rb_define_private_method(cPsychVisitorsToRuby, "build_exception", build_exception, 2);
+    rb_define_private_method(cPsychVisitorsToRuby, "path2class", path2class, 1);
+}
+/* vim: set noet sws=4 sw=4: */
--- a/ext/psych/to_ruby.h
+++ b/ext/psych/to_ruby.h
@ -0,0 +1,8 @@
+#ifndef PSYCH_TO_RUBY_H
+#define PSYCH_TO_RUBY_H
+
+#include <psych.h>
+
+void Init_psych_to_ruby(void);
+
+#endif
--- a/ext/psych/yaml_tree.c
+++ b/ext/psych/yaml_tree.c
@ -0,0 +1,24 @@
+#include <psych.h>
+
+VALUE cPsychVisitorsYamlTree;
+
+/*
+ * call-seq: private_iv_get(target, prop)
+ *
+ * Get the private instance variable +prop+ from +target+
+ */
+static VALUE private_iv_get(VALUE self, VALUE target, VALUE prop)
+{
+    return rb_attr_get(target, rb_intern(StringValuePtr(prop)));
+}
+
+void Init_psych_yaml_tree(void)
+{
+    VALUE psych     = rb_define_module("Psych");
+    VALUE visitors  = rb_define_module_under(psych, "Visitors");
+    VALUE visitor   = rb_define_class_under(visitors, "Visitor", rb_cObject);
+    cPsychVisitorsYamlTree = rb_define_class_under(visitors, "YAMLTree", visitor);
+
+    rb_define_private_method(cPsychVisitorsYamlTree, "private_iv_get", private_iv_get, 2);
+}
+/* vim: set noet sws=4 sw=4: */
--- a/ext/psych/yaml_tree.h
+++ b/ext/psych/yaml_tree.h
@ -0,0 +1,8 @@
+#ifndef PSYCH_YAML_TREE_H
+#define PSYCH_YAML_TREE_H
+
+#include <psych.h>
+
+void Init_psych_yaml_tree(void);
+
+#endif
--- a/lib/psych.rb
+++ b/lib/psych.rb
@ -0,0 +1,236 @@
+require 'psych/psych'
+require 'psych/nodes'
+require 'psych/visitors'
+require 'psych/handler'
+require 'psych/tree_builder'
+require 'psych/parser'
+require 'psych/omap'
+require 'psych/set'
+require 'psych/coder'
+require 'psych/core_ext'
+
+###
+# = Overview
+#
+# Psych is a YAML parser and emitter.  Psych leverages
+# libyaml[http://libyaml.org] for it's YAML parsing and emitting capabilities.
+# In addition to wrapping libyaml, Psych also knows how to serialize and
+# de-serialize most Ruby objects to and from the YAML format.
+#
+# = I NEED TO PARSE OR EMIT YAML RIGHT NOW!
+#
+#   # Parse some YAML
+#   Psych.load("--- foo") # => "foo"
+#
+#   # Emit some YAML
+#   Psych.dump("foo")     # => "--- foo\n...\n"
+#   { :a => 'b'}.to_yaml  # => "---\n:a: b\n"
+#
+# Got more time on your hands?  Keep on reading!
+#
+# == YAML Parsing
+#
+# Psych provides a range of interfaces for parsing a YAML document ranging from
+# low level to high level, depending on your parsing needs.  At the lowest
+# level, is an event based parser.  Mid level is access to the raw YAML AST,
+# and at the highest level is the ability to unmarshal YAML to ruby objects.
+#
+# === Low level parsing
+#
+# The lowest level parser should be used when the YAML input is already known,
+# and the developer does not want to pay the price of building an AST or
+# automatic detection and conversion to ruby objects.  See Psych::Parser for
+# more information on using the event based parser.
+#
+# === Mid level parsing
+#
+# Psych provides access to an AST produced from parsing a YAML document.  This
+# tree is built using the Psych::Parser and Psych::TreeBuilder.  The AST can
+# be examined and manipulated freely.  Please see Psych::parse_stream,
+# Psych::Nodes, and Psych::Nodes::Node for more information on dealing with
+# YAML syntax trees.
+#
+# === High level parsing
+#
+# The high level YAML parser provided by Psych simply takes YAML as input and
+# returns a Ruby data structure.  For information on using the high level parser
+# see Psych.load
+#
+# == YAML Emitting
+#
+# Psych provides a range of interfaces ranging from low to high level for
+# producing YAML documents.  Very similar to the YAML parsing interfaces, Psych
+# provides at the lowest level, an event based system, mid-level is building
+# a YAML AST, and the highest level is converting a Ruby object straight to
+# a YAML document.
+#
+# === Low level emitting
+#
+# The lowest level emitter is an event based system.  Events are sent to a
+# Psych::Emitter object.  That object knows how to convert the events to a YAML
+# document.  This interface should be used when document format is known in
+# advance or speed is a concern.  See Psych::Emitter for more information.
+#
+# === Mid level emitting
+#
+# At the mid level is building an AST.  This AST is exactly the same as the AST
+# used when parsing a YAML document.  Users can build an AST by hand and the
+# AST knows how to emit itself as a YAML document.  See Psych::Nodes,
+# Psych::Nodes::Node, and Psych::TreeBuilder for more information on building
+# a YAML AST.
+#
+# === High level emitting
+#
+# The high level emitter has the easiest interface.  Psych simply takes a Ruby
+# data structure and converts it to a YAML document.  See Psych.dump for more
+# information on dumping a Ruby data structure.
+
+module Psych
+  # The version is Psych you're using
+  VERSION         = '1.0.0'
+
+  # The version of libyaml Psych is using
+  LIBYAML_VERSION = Psych.libyaml_version.join '.'
+
+  ###
+  # Load +yaml+ in to a Ruby data structure.  If multiple documents are
+  # provided, the object contained in the first document will be returned.
+  #
+  # Example:
+  #
+  #   Psych.load("--- a")           # => 'a'
+  #   Psych.load("---\n - a\n - b") # => ['a', 'b']
+  def self.load yaml
+    parse(yaml).to_ruby
+  end
+
+  ###
+  # Parse a YAML string in +yaml+.  Returns the first object of a YAML AST.
+  #
+  # Example:
+  #
+  #   Psych.load("---\n - a\n - b") # => #<Psych::Nodes::Sequence:0x00>
+  #
+  # See Psych::Nodes for more information about YAML AST.
+  def self.parse yaml
+    parse_stream(yaml).children.first.children.first
+  end
+
+  ###
+  # Parse a file at +filename+. Returns the YAML AST.
+  def self.parse_file filename
+    File.open filename do |f|
+      parse f
+    end
+  end
+
+  ###
+  # Returns a default parser
+  def self.parser
+    Psych::Parser.new(TreeBuilder.new)
+  end
+
+  ###
+  # Parse a YAML string in +yaml+.  Returns the full AST for the YAML document.
+  # This method can handle multiple YAML documents contained in +yaml+.
+  #
+  # Example:
+  #
+  #   Psych.load("---\n - a\n - b") # => #<Psych::Nodes::Stream:0x00>
+  #
+  # See Psych::Nodes for more information about YAML AST.
+  def self.parse_stream yaml
+    parser = self.parser
+    parser.parse yaml
+    parser.handler.root
+  end
+
+  ###
+  # Dump Ruby object +o+ to a YAML string using +options+.
+  #
+  # Example:
+  #
+  #   Psych.dump(['a', 'b'])  # => "---\n- a\n- b\n"
+  def self.dump o, options = {}
+    visitor = Psych::Visitors::YAMLTree.new options
+    visitor << o
+    visitor.tree.to_yaml
+  end
+
+  ###
+  # Dump a list of objects as separate documents to a document stream.
+  #
+  # Example:
+  #
+  #   Psych.dump_stream("foo\n  ", {}) # => "--- ! \"foo\\n  \"\n--- {}\n"
+  def self.dump_stream *objects
+    visitor = Psych::Visitors::YAMLTree.new {}
+    objects.each do |o|
+      visitor << o
+    end
+    visitor.tree.to_yaml
+  end
+
+  ###
+  # Dump Ruby object +o+ to a JSON string.
+  def self.to_json o
+    visitor = Psych::Visitors::JSONTree.new(:json => true)
+    visitor << o
+    visitor.tree.to_yaml
+  end
+
+  ###
+  # Load multiple documents given in +yaml+.  Returns the parsed documents
+  # as a list.  For example:
+  #
+  #   Psych.load_documents("--- foo\n...\n--- bar\n...") # => ['foo', 'bar']
+  #
+  def self.load_stream yaml
+    parse_stream(yaml).children.map { |child| child.to_ruby }
+  end
+
+  def self.load_documents yaml, &block
+    if $VERBOSE
+      warn "#{caller[0]}: load_documents is deprecated, use load_stream"
+    end
+    list = load_stream yaml
+    return list unless block_given?
+    list.each(&block)
+  end
+
+  ###
+  # Load the document contained in +filename+.  Returns the yaml contained in
+  # +filename+ as a ruby object
+  def self.load_file filename
+    self.load File.open(filename)
+  end
+
+  # :stopdoc:
+  @domain_types = {}
+  def self.add_domain_type domain, type_tag, &block
+    @domain_types[type_tag] = ["http://#{domain}", block]
+  end
+
+  def self.add_builtin_type type_tag, &block
+    @domain_types[type_tag] = ['yaml.org', block]
+  end
+
+  def self.remove_type type_tag
+    @domain_types.delete type_tag
+  end
+
+  @load_tags = {}
+  @dump_tags = {}
+  def self.add_tag tag, klass
+    @load_tags[tag] = klass
+    @dump_tags[klass] = tag
+  end
+
+  class << self
+    attr_accessor :load_tags
+    attr_accessor :dump_tags
+    attr_accessor :domain_types
+  end
+
+  # :startdoc:
+end
--- a/lib/psych/coder.rb
+++ b/lib/psych/coder.rb
@ -0,0 +1,68 @@
+module Psych
+  ###
+  # If an object defines +encode_with+, then an instance of Psych::Coder will
+  # passed to the method when the object is being serialized.  The Coder
+  # automatically assumes a Psych::Nodes::Mapping is being emitted.  Other
+  # objects like Sequence and Scalar may be emitted if +seq=+ or +scalar=+ are
+  # called, respectively.
+  class Coder
+    attr_accessor :tag, :style, :implicit
+    attr_reader   :type, :map, :scalar, :seq
+
+    def initialize tag
+      @map        = {}
+      @seq        = []
+      @implicit   = false
+      @type       = :map
+      @tag        = tag
+      @style      = Psych::Nodes::Mapping::BLOCK
+      @scalar     = nil
+    end
+
+    # Emit a scalar with +value+ and +tag+
+    def represent_scalar tag, value
+      self.tag    = tag
+      self.scalar = value
+    end
+
+    # Emit a sequence with +list+ and +tag+
+    def represent_seq tag, list
+      @tag = tag
+      self.seq = list
+    end
+
+    # Emit a sequence with +map+ and +tag+
+    def represent_map tag, map
+      @tag = tag
+      self.map = map
+    end
+
+    # Emit a scalar with +value+
+    def scalar= value
+      @type   = :scalar
+      @scalar = value
+    end
+
+    # Emit a map with +value+
+    def map= map
+      @type = :map
+      @map  = map
+    end
+
+    def []= k, v
+      @type = :map
+      @map[k] = v
+    end
+
+    def [] k
+      @type = :map
+      @map[k]
+    end
+
+    # Emit a sequence of +list+
+    def seq= list
+      @type = :seq
+      @seq  = list
+    end
+  end
+end
--- a/lib/psych/core_ext.rb
+++ b/lib/psych/core_ext.rb
@ -0,0 +1,22 @@
+class Object
+  def self.yaml_tag url
+    Psych.add_tag(url, self)
+  end
+
+  # FIXME: rename this to "to_yaml" when syck is removed
+
+  ###
+  # call-seq: to_yaml
+  #
+  # Convert an object to YAML
+  def psych_to_yaml options = {}
+    Psych.dump self, options
+  end
+  alias :to_yaml :psych_to_yaml
+end
+
+module Kernel
+  def y *objects
+    puts Psych.dump_stream(*objects)
+  end
+end
--- a/lib/psych/emitter.rb
+++ b/lib/psych/emitter.rb
@ -0,0 +1,4 @@
+module Psych
+  class Emitter < Psych::Handler
+  end
+end
--- a/lib/psych/handler.rb
+++ b/lib/psych/handler.rb
@ -0,0 +1,215 @@
+module Psych
+  ###
+  # Psych::Handler is an abstract base class that defines the events used
+  # when dealing with Psych::Parser.  Clients who want to use Psych::Parser
+  # should implement a class that inherits from Psych::Handler and define
+  # events that they can handle.
+  #
+  # Psych::Handler defines all events that Psych::Parser can possibly send to
+  # event handlers.
+  #
+  # See Psych::Parser for more details
+  class Handler
+    ###
+    # Called with +encoding+ when the YAML stream starts.  This method is
+    # called once per stream.  A stream may contain multiple documents.
+    #
+    # See the constants in Psych::Parser for the possible values of +encoding+.
+    def start_stream encoding
+    end
+
+    ###
+    # Called when the document starts with the declared +version+,
+    # +tag_directives+, if the document is +implicit+.
+    #
+    # +version+ will be an array of integers indicating the YAML version being
+    # dealt with, +tag_directives+ is a list of tuples indicating the prefix
+    # and suffix of each tag, and +implicit+ is a boolean indicating whether
+    # the document is started implicitly.
+    #
+    # === Example
+    #
+    # Given the following YAML:
+    #
+    #   %YAML 1.1
+    #   %TAG ! tag:tenderlovemaking.com,2009:
+    #   --- !squee
+    #
+    # The parameters for start_document must be this:
+    #
+    #   version         # => [1, 1]
+    #   tag_directives  # => [["!", "tag:tenderlovemaking.com,2009:"]]
+    #   implicit        # => false
+    def start_document version, tag_directives, implicit
+    end
+
+    ###
+    # Called with the document ends.  +implicit+ is a boolean value indicating
+    # whether or not the document has an implicit ending.
+    #
+    # === Example
+    #
+    # Given the following YAML:
+    #
+    #   ---
+    #     hello world
+    #
+    # +implicit+ will be true.  Given this YAML:
+    #
+    #   ---
+    #     hello world
+    #   ...
+    #
+    # +implicit+ will be false.
+    def end_document implicit
+    end
+
+    ###
+    # Called when an alias is found to +anchor+.  +anchor+ will be the name
+    # of the anchor found.
+    #
+    # === Example
+    #
+    # Here we have an example of an array that references itself in YAML:
+    #
+    #   --- &ponies
+    #   - first element
+    #   - *ponies
+    #
+    # &ponies is the achor, *ponies is the alias.  In this case, alias is
+    # called with "ponies".
+    def alias anchor
+    end
+
+    ###
+    # Called when a scalar +value+ is found.  The scalar may have an
+    # +anchor+, a +tag+, be implicitly +plain+ or implicitly +quoted+
+    #
+    # +value+ is the string value of the scalar
+    # +anchor+ is an associated anchor or nil
+    # +tag+ is an associated tag or nil
+    # +plain+ is a boolean value
+    # +quoted+ is a boolean value
+    # +style+ is an integer idicating the string style
+    #
+    # See the constants in Psych::Nodes::Scalar for the possible values of
+    # +style+
+    #
+    # === Example
+    #
+    # Here is a YAML document that exercises most of the possible ways this
+    # method can be called:
+    #
+    #   ---
+    #   - !str "foo"
+    #   - &anchor fun
+    #   - many
+    #     lines
+    #   - |
+    #     many
+    #     newlines
+    #
+    # The above YAML document contains a list with four strings.  Here are
+    # the parameters sent to this method in the same order:
+    #
+    #   # value               anchor    tag     plain   quoted  style
+    #   ["foo",               nil,      "!str", false,  false,  3    ]
+    #   ["fun",               "anchor", nil,    true,   false,  1    ]
+    #   ["many lines",        nil,      nil,    true,   false,  1    ]
+    #   ["many\nnewlines\n",  nil,      nil,    false,  true,   4    ]
+    #
+    def scalar value, anchor, tag, plain, quoted, style
+    end
+
+    ###
+    # Called when a sequence is started.
+    #
+    # +anchor+ is the anchor associated with the sequence or nil.
+    # +tag+ is the tag associated with the sequence or nil.
+    # +implicit+ a boolean indicating whether or not the sequence was implicitly
+    # started.
+    # +style+ is an integer indicating the list style.
+    #
+    # See the constants in Psych::Nodes::Sequence for the possible values of
+    # +style+.
+    #
+    # === Example
+    #
+    # Here is a YAML document that exercises most of the possible ways this
+    # method can be called:
+    #
+    #   ---
+    #   - !!seq [
+    #     a
+    #   ]
+    #   - &pewpew
+    #     - b
+    #
+    # The above YAML document consists of three lists, an outer list that
+    # contains two inner lists.  Here is a matrix of the parameters sent
+    # to represent these lists:
+    #
+    #   # anchor    tag                       implicit  style
+    #   [nil,       nil,                      true,     1     ]
+    #   [nil,       "tag:yaml.org,2002:seq",  false,    2     ]
+    #   ["pewpew",  nil,                      true,     1     ]
+
+    def start_sequence anchor, tag, implicit, style
+    end
+
+    ###
+    # Called when a sequence ends.
+    def end_sequence
+    end
+
+    ###
+    # Called when a map starts.
+    #
+    # +anchor+ is the anchor associated with the map or +nil+.
+    # +tag+ is the tag associated with the map or +nil+.
+    # +implicit+ is a boolean indicating whether or not the map was implicitly
+    # started.
+    # +style+ is an integer indicating the mapping style.
+    #
+    # See the constants in Psych::Nodes::Mapping for the possible values of
+    # +style+.
+    #
+    # === Example
+    #
+    # Here is a YAML document that exercises most of the possible ways this
+    # method can be called:
+    #
+    #   ---
+    #   k: !!map { hello: world }
+    #   v: &pewpew
+    #     hello: world
+    #
+    # The above YAML document consists of three maps, an outer map that contains
+    # two inner maps.  Below is a matrix of the parameters sent in order to
+    # represent these three maps:
+    #
+    #   # anchor    tag                       implicit  style
+    #   [nil,       nil,                      true,     1     ]
+    #   [nil,       "tag:yaml.org,2002:map",  false,    2     ]
+    #   ["pewpew",  nil,                      true,     1     ]
+
+    def start_mapping anchor, tag, implicit, style
+    end
+
+    ###
+    # Called when a map ends
+    def end_mapping
+    end
+
+    ###
+    # Called when an empty event happens. (Which, as far as I can tell, is
+    # never).
+    def empty
+    end
+
+    ###
+    # Called when the YAML stream ends
+    def end_stream
+    end
+  end
+end
--- a/lib/psych/nodes.rb
+++ b/lib/psych/nodes.rb
@ -0,0 +1,77 @@
+require 'psych/nodes/node'
+require 'psych/nodes/stream'
+require 'psych/nodes/document'
+require 'psych/nodes/sequence'
+require 'psych/nodes/scalar'
+require 'psych/nodes/mapping'
+require 'psych/nodes/alias'
+
+module Psych
+  ###
+  # = Overview
+  #
+  # When using Psych.load to deserialize a YAML document, the document is
+  # translated to an intermediary AST.  That intermediary AST is then
+  # translated in to a Ruby object graph.
+  #
+  # In the opposite direction, when using Psych.dump, the Ruby object graph is
+  # translated to an intermediary AST which is then converted to a YAML
+  # document.
+  #
+  # Psych::Nodes contains all of the classes that make up the nodes of a YAML
+  # AST.  You can manually build an AST and use one of the visitors (see
+  # Psych::Visitors) to convert that AST to either a YAML document or to a
+  # Ruby object graph.
+  #
+  # Here is an example of building an AST that represents a list with one
+  # scalar:
+  #
+  #   # Create our nodes
+  #   stream = Psych::Nodes::Stream.new
+  #   doc    = Psych::Nodes::Document.new
+  #   seq    = Psych::Nodes::Sequence.new
+  #   scalar = Psych::Nodes::Scalar.new('foo')
+  #   
+  #   # Build up our tree
+  #   stream.children << doc
+  #   doc.children    << seq
+  #   seq.children    << scalar
+  #
+  # The stream is the root of the tree.  We can then convert the tree to YAML:
+  #
+  #   stream.to_yaml => "---\n- foo\n"
+  #
+  # Or convert it to Ruby:
+  #
+  #   stream.to_ruby => [["foo"]]
+  #
+  # == YAML AST Requirements
+  #
+  # A valid YAML AST *must* have one Psych::Nodes::Stream at the root.  A
+  # Psych::Nodes::Stream node must have 1 or more Psych::Nodes::Document nodes
+  # as children.
+  #
+  # Psych::Nodes::Document nodes must have one and *only* one child.  That child
+  # may be one of:
+  #
+  # * Psych::Nodes::Sequence
+  # * Psych::Nodes::Mapping
+  # * Psych::Nodes::Scalar
+  #
+  # Psych::Nodes::Sequence and Psych::Nodes::Mapping nodes may have many
+  # children, but Psych::Nodes::Mapping nodes should have an even number of
+  # children.
+  #
+  # All of these are valid children for Psych::Nodes::Sequence and
+  # Psych::Nodes::Mapping nodes:
+  #
+  # * Psych::Nodes::Sequence
+  # * Psych::Nodes::Mapping
+  # * Psych::Nodes::Scalar
+  # * Psych::Nodes::Alias
+  #
+  # Psych::Nodes::Scalar and Psych::Nodes::Alias are both terminal nodes and
+  # should not have any children.
+  module Nodes
+  end
+end
--- a/lib/psych/nodes/alias.rb
+++ b/lib/psych/nodes/alias.rb
@ -0,0 +1,18 @@
+module Psych
+  module Nodes
+    ###
+    # This class represents a {YAML Alias}[http://yaml.org/spec/1.1/#alias].
+    # It points to an +anchor+.
+    #
+    # A Psych::Nodes::Alias is a terminal node and may have no children.
+    class Alias < Psych::Nodes::Node
+      # The anchor this alias links to
+      attr_accessor :anchor
+
+      # Create a new Alias that points to an +anchor+
+      def initialize anchor
+        @anchor = anchor
+      end
+    end
+  end
+end
--- a/lib/psych/nodes/document.rb
+++ b/lib/psych/nodes/document.rb
@ -0,0 +1,60 @@
+module Psych
+  module Nodes
+    ###
+    # This represents a YAML Document.  This node must be a child of
+    # Psych::Nodes::Stream.  A Psych::Nodes::Document must have one child,
+    # and that child may be one of the following:
+    #
+    # * Psych::Nodes::Sequence
+    # * Psych::Nodes::Mapping
+    # * Psych::Nodes::Scalar
+    class Document < Psych::Nodes::Node
+      # The version of the YAML document
+      attr_accessor :version
+
+      # A list of tag directives for this document
+      attr_accessor :tag_directives
+
+      # Was this document implicitly created?
+      attr_accessor :implicit
+
+      # Is the end of the document implicit?
+      attr_accessor :implicit_end
+
+      ###
+      # Create a new Psych::Nodes::Document object.
+      #
+      # +version+ is a list indicating the YAML version.
+      # +tags_directives+ is a list of tag directive declarations
+      # +implicit+ is a flag indicating whether the document will be implicitly
+      # started.
+      #
+      # == Example:
+      # This creates a YAML document object that represents a YAML 1.1 document
+      # with one tag directive, and has an implicit start:
+      #
+      #   Psych::Nodes::Document.new(
+      #     [1,1],
+      #     [["!", "tag:tenderlovemaking.com,2009:"]],
+      #     true
+      #   )
+      #
+      # == See Also
+      # See also Psych::Handler#start_document
+      def initialize version = [], tag_directives = [], implicit = false
+        super()
+        @version        = version
+        @tag_directives = tag_directives
+        @implicit       = implicit
+        @implicit_end   = true
+      end
+
+      ###
+      # Returns the root node.  A Document may only have one root node:
+      # http://yaml.org/spec/1.1/#id898031
+      def root
+        children.first
+      end
+    end
+  end
+end
--- a/lib/psych/nodes/mapping.rb
+++ b/lib/psych/nodes/mapping.rb
@ -0,0 +1,56 @@
+module Psych
+  module Nodes
+    ###
+    # This class represents a {YAML Mapping}[http://yaml.org/spec/1.1/#mapping].
+    #
+    # A Psych::Nodes::Mapping node may have 0 or more children, but must have
+    # an even number of children.  Here are the valid children a
+    # Psych::Nodes::Mapping node may have:
+    #
+    # * Psych::Nodes::Sequence
+    # * Psych::Nodes::Mapping
+    # * Psych::Nodes::Scalar
+    # * Psych::Nodes::Alias
+    class Mapping < Psych::Nodes::Node
+      # Any Map Style
+      ANY   = 0
+
+      # Block Map Style
+      BLOCK = 1
+
+      # Flow Map Style
+      FLOW  = 2
+
+      # The optional anchor for this mapping
+      attr_accessor :anchor
+
+      # The optional tag for this mapping
+      attr_accessor :tag
+
+      # Is this an implicit mapping?
+      attr_accessor :implicit
+
+      # The style of this mapping
+      attr_accessor :style
+
+      ###
+      # Create a new Psych::Nodes::Mapping object.
+      #
+      # +anchor+ is the anchor associated with the map or +nil+.
+      # +tag+ is the tag associated with the map or +nil+.
+      # +implicit+ is a boolean indicating whether or not the map was implicitly
+      # started.
+      # +style+ is an integer indicating the mapping style.
+      #
+      # == See Also
+      # See also Psych::Handler#start_mapping
+      def initialize anchor = nil, tag = nil, implicit = true, style = BLOCK
+        super()
+        @anchor   = anchor
+        @tag      = tag
+        @implicit = implicit
+        @style    = style
+      end
+    end
+  end
+end
--- a/lib/psych/nodes/node.rb
+++ b/lib/psych/nodes/node.rb
@ -0,0 +1,40 @@
+require 'stringio'
+
+module Psych
+  module Nodes
+    ###
+    # The base class for any Node in a YAML parse tree.  This class should
+    # never be instantiated.
+    class Node
+      # The children of this node
+      attr_reader :children
+
+      # An associated tag
+      attr_reader :tag
+
+      # Create a new Psych::Nodes::Node
+      def initialize
+        @children = []
+      end
+
+      ###
+      # Convert this node to Ruby.
+      #
+      # See also Psych::Visitors::ToRuby
+      def to_ruby
+        Visitors::ToRuby.new.accept self
+      end
+      alias :transform :to_ruby
+
+      ###
+      # Convert this node to YAML.
+      #
+      # See also Psych::Visitors::Emitter
+      def to_yaml
+        io = StringIO.new
+        Visitors::Emitter.new(io).accept self
+        io.string
+      end
+    end
+  end
+end
--- a/lib/psych/nodes/scalar.rb
+++ b/lib/psych/nodes/scalar.rb
@ -0,0 +1,67 @@
+module Psych
+  module Nodes
+    ###
+    # This class represents a {YAML Scalar}[http://yaml.org/spec/1.1/#id858081].
+    #
+    # This node type is a terminal node and should not have any children.
+    class Scalar < Psych::Nodes::Node
+      # Any style scalar, the emitter chooses
+      ANY           = 0
+
+      # Plain scalar style
+      PLAIN         = 1
+
+      # Single quoted style
+      SINGLE_QUOTED = 2
+
+      # Double quoted style
+      DOUBLE_QUOTED = 3
+
+      # Literal style
+      LITERAL       = 4
+
+      # Folded style
+      FOLDED        = 5
+
+      # The scalar value
+      attr_accessor :value
+
+      # The anchor value (if there is one)
+      attr_accessor :anchor
+
+      # The tag value (if there is one)
+      attr_accessor :tag
+
+      # Is this a plain scalar?
+      attr_accessor :plain
+
+      # Is this scalar quoted?
+      attr_accessor :quoted
+
+      # The style of this scalar
+      attr_accessor :style
+
+      ###
+      # Create a new Psych::Nodes::Scalar object.
+      #
+      # +value+ is the string value of the scalar
+      # +anchor+ is an associated anchor or nil
+      # +tag+ is an associated tag or nil
+      # +plain+ is a boolean value
+      # +quoted+ is a boolean value
+      # +style+ is an integer idicating the string style
+      #
+      # == See Also
+      #
+      # See also Psych::Handler#scalar
+      def initialize value, anchor = nil, tag = nil, plain = true, quoted = false, style = ANY
+        @value  = value
+        @anchor = anchor
+        @tag    = tag
+        @plain  = plain
+        @quoted = quoted
+        @style  = style
+      end
+    end
+  end
+end
--- a/lib/psych/nodes/sequence.rb
+++ b/lib/psych/nodes/sequence.rb
@ -0,0 +1,81 @@
+module Psych
+  module Nodes
+    ###
+    # This class represents a
+    # {YAML sequence}[http://yaml.org/spec/1.1/#sequence/syntax].
+    #
+    # A YAML sequence is basically a list, and looks like this:
+    #
+    #   %YAML 1.1
+    #   ---
+    #   - I am
+    #   - a Sequence
+    #
+    # A YAML sequence may have an anchor like this:
+    #
+    #   %YAML 1.1
+    #   ---
+    #   &A [
+    #     "This sequence",
+    #     "has an anchor"
+    #   ]
+    #
+    # A YAML sequence may also have a tag like this:
+    #
+    #   %YAML 1.1
+    #   ---
+    #   !!seq [
+    #     "This sequence",
+    #     "has a tag"
+    #   ]
+    #
+    # This class represents a sequence in a YAML document.  A
+    # Psych::Nodes::Sequence node may have 0 or more children.  Valid children
+    # for this node are:
+    #
+    # * Psych::Nodes::Sequence
+    # * Psych::Nodes::Mapping
+    # * Psych::Nodes::Scalar
+    # * Psych::Nodes::Alias
+    class Sequence < Psych::Nodes::Node
+      # Any Styles, emitter chooses
+      ANY   = 0
+
+      # Block style sequence
+      BLOCK = 1
+
+      # Flow style sequence
+      FLOW  = 2
+
+      # The anchor for this sequence (if any)
+      attr_accessor :anchor
+
+      # The tag name for this sequence (if any)
+      attr_accessor :tag
+
+      # Is this sequence started implicitly?
+      attr_accessor :implicit
+
+      # The sequece style used
+      attr_accessor :style
+
+      ###
+      # Create a new object representing a YAML sequence.
+      #
+      # +anchor+ is the anchor associated with the sequence or nil.
+      # +tag+ is the tag associated with the sequence or nil.
+      # +implicit+ a boolean indicating whether or not the sequence was
+      # implicitly started.
+      # +style+ is an integer indicating the list style.
+      #
+      # See Psych::Handler#start_sequence
+      def initialize anchor = nil, tag = nil, implicit = true, style = BLOCK
+        super()
+        @anchor   = anchor
+        @tag      = tag
+        @implicit = implicit
+        @style    = style
+      end
+    end
+  end
+end
--- a/lib/psych/nodes/stream.rb
+++ b/lib/psych/nodes/stream.rb
@ -0,0 +1,37 @@
+module Psych
+  module Nodes
+    ###
+    # Represents a YAML stream.  This is the root node for any YAML parse
+    # tree.  This node must have one or more child nodes.  The only valid
+    # child node for a Psych::Nodes::Stream node is Psych::Nodes::Document.
+    class Stream < Psych::Nodes::Node
+
+      # Encodings supported by Psych (and libyaml)
+
+      # Any encoding
+      ANY     = Psych::Parser::ANY
+
+      # UTF-8 encoding
+      UTF8    = Psych::Parser::UTF8
+
+      # UTF-16LE encoding
+      UTF16LE = Psych::Parser::UTF16LE
+
+      # UTF-16BE encoding
+      UTF16BE = Psych::Parser::UTF16BE
+
+      # The encoding used for this stream
+      attr_reader :encoding
+
+      ###
+      # Create a new Psych::Nodes::Stream node with an +encoding+ that
+      # defaults to Psych::Nodes::Stream::UTF8.
+      #
+      # See also Psych::Handler#start_stream
+      def initialize encoding = UTF8
+        super()
+        @encoding = encoding
+      end
+    end
+  end
+end
--- a/lib/psych/omap.rb
+++ b/lib/psych/omap.rb
@ -0,0 +1,4 @@
+module Psych
+  class Omap < ::Hash
+  end
+end
--- a/lib/psych/parser.rb
+++ b/lib/psych/parser.rb
@ -0,0 +1,44 @@
+module Psych
+  ###
+  # YAML event parser class.  This class parses a YAML document and calls
+  # events on the handler that is passed to the constructor.  The events can
+  # be used for things such as constructing a YAML AST or deserializing YAML
+  # documents.  It can even be fed back to Psych::Emitter to emit the same
+  # document that was parsed.
+  #
+  # See Psych::Handler for documentation on the events that Psych::Parser emits.
+  #
+  # Here is an example that prints out ever scalar found in a YAML document:
+  #
+  #   # Handler for detecting scalar values
+  #   class ScalarHandler < Psych::Handler
+  #     def scalar value, anchor, tag, plain, quoted, style
+  #       puts value
+  #     end
+  #   end
+  #
+  #   parser = Psych::Parser.new(ScalarHandler.new)
+  #   parser.parse(yaml_document)
+  #
+  # Here is an example that feeds the parser back in to Psych::Emitter.  The
+  # YAML document is read from STDIN and written back out to STDERR:
+  #
+  #   parser = Psych::Parser.new(Psych::Emitter.new($stderr))
+  #   parser.parse($stdin)
+  #
+  # Psych uses Psych::Parser in combination with Psych::TreeBuilder to
+  # construct an AST of the parsed YAML document.
+
+  class Parser
+    # The handler on which events will be called
+    attr_accessor :handler
+
+    ###
+    # Creates a new Psych::Parser instance with +handler+.  YAML events will
+    # be called on +handler+.  See Psych::Parser for more details.
+
+    def initialize handler = Handler.new
+      @handler = handler
+    end
+  end
+end
--- a/lib/psych/scalar_scanner.rb
+++ b/lib/psych/scalar_scanner.rb
@ -0,0 +1,90 @@
+require 'strscan'
+
+module Psych
+  ###
+  # Scan scalars for built in types
+  class ScalarScanner
+    # Taken from http://yaml.org/type/timestamp.html
+    TIME = /^\d{4}-\d{1,2}-\d{1,2}([Tt]|\s+)\d{1,2}:\d\d:\d\d(\.\d*)?(\s*Z|[-+]\d{1,2}(:\d\d)?)?/
+
+    # Create a new scanner
+    def initialize
+      @string_cache = {}
+    end
+
+    # Tokenize +string+ returning the ruby object
+    def tokenize string
+      return nil if string.empty?
+      return string if @string_cache.key?(string)
+
+      case string
+      when /^[A-Za-z~]/
+        if string.length > 5
+          @string_cache[string] = true
+          return string
+        end
+
+        case string
+        when /^[^ytonf~]/i
+          @string_cache[string] = true
+          string
+        when '~', /^null$/i
+          nil
+        when /^(yes|true|on)$/i
+          true
+        when /^(no|false|off)$/i
+          false
+        else
+          @string_cache[string] = true
+          string
+        end
+      when TIME
+        date, time = *(string.split(/[ tT]/, 2))
+        (yy, m, dd) = date.split('-').map { |x| x.to_i }
+        md = time.match(/(\d+:\d+:\d+)(\.\d*)?\s*(Z|[-+]\d+(:\d\d)?)?/)
+
+        (hh, mm, ss) = md[1].split(':').map { |x| x.to_i }
+        us = (md[2] ? Rational(md[2].sub(/^\./, '0.')) : 0) * 1000000
+
+        time = Time.utc(yy, m, dd, hh, mm, ss, us)
+
+        return time if 'Z' == md[3]
+
+        tz = md[3] ? Integer(md[3].split(':').first.sub(/([-+])0/, '\1')) : 0
+        Time.at((time - (tz * 3600)).to_i, us)
+      when /^\d{4}-\d{1,2}-\d{1,2}$/
+        require 'date'
+        Date.strptime(string, '%Y-%m-%d')
+      when /^\.inf$/i
+        1 / 0.0
+      when /^-\.inf$/i
+        -1 / 0.0
+      when /^\.nan$/i
+        0.0 / 0.0
+      when /^:./
+        if string =~ /^:(["'])(.*)\1/
+          $2.sub(/^:/, '').to_sym
+        else
+          string.sub(/^:/, '').to_sym
+        end
+      when /^[-+]?[1-9][0-9_]*(:[0-5]?[0-9])+$/
+        i = 0
+        string.split(':').each_with_index do |n,e|
+          i += (n.to_i * 60 ** (e - 2).abs)
+        end
+        i
+      when /^[-+]?[0-9][0-9_]*(:[0-5]?[0-9])+\.[0-9_]*$/
+        i = 0
+        string.split(':').each_with_index do |n,e|
+          i += (n.to_f * 60 ** (e - 2).abs)
+        end
+        i
+      else
+        return Integer(string.gsub(/[,_]/, '')) rescue ArgumentError
+        return Float(string.gsub(/[,_]/, '')) rescue ArgumentError
+        @string_cache[string] = true
+        string
+      end
+    end
+  end
+end
--- a/lib/psych/set.rb
+++ b/lib/psych/set.rb
@ -0,0 +1,4 @@
+module Psych
+  class Set < ::Hash
+  end
+end
--- a/lib/psych/tree_builder.rb
+++ b/lib/psych/tree_builder.rb
@ -0,0 +1,89 @@
+require 'psych/handler'
+
+module Psych
+  ###
+  # This class works in conjunction with Psych::Parser to build an in-memory
+  # parse tree tree that represents a YAML document.
+  #
+  # == Example
+  #
+  #   parser = Psych::Parser.new Psych::TreeBuilder.new
+  #   parser.parse('--- foo')
+  #   tree = parser.handler.root
+  #
+  # See Psych::Handler for documentation on the event methods used in this
+  # class.
+  class TreeBuilder < Psych::Handler
+    # Create a new TreeBuilder instance
+    def initialize
+      @stack = []
+      @last  = nil
+    end
+
+    # Returns the root node for the built tree
+    def root
+      @stack.first
+    end
+
+    %w{
+      Sequence
+      Mapping
+    }.each do |node|
+      class_eval %{
+        def start_#{node.downcase}(anchor, tag, implicit, style)
+          n = Nodes::#{node}.new(anchor, tag, implicit, style)
+          @last.children << n
+          push n
+        end
+
+        def end_#{node.downcase}
+          pop
+        end
+      }
+    end
+
+    ###
+    # Handles start_document events with +version+, +tag_directives+,
+    # and +implicit+ styling.
+    #
+    # See Psych::Handler#start_document
+    def start_document version, tag_directives, implicit
+      n = Nodes::Document.new(version, tag_directives, implicit)
+      @last.children << n
+      push n
+    end
+
+    ###
+    # Handles end_document events with +version+, +tag_directives+,
+    # and +implicit+ styling.
+    #
+    # See Psych::Handler#start_document
+    def end_document implicit_end
+      @last.implicit_end = implicit_end
+      pop
+    end
+
+    def start_stream encoding
+      push Nodes::Stream.new(encoding)
+    end
+
+    def scalar value, anchor, tag, plain, quoted, style
+      @last.children << Nodes::Scalar.new(value,anchor,tag,plain,quoted,style)
+    end
+
+    def alias anchor
+      @last.children << Nodes::Alias.new(anchor)
+    end
+
+    private
+    def push value
+      @stack.push value
+      @last = value
+    end
+
+    def pop
+      @stack.pop
+      @last = @stack.last
+    end
+  end
+end
--- a/lib/psych/visitors.rb
+++ b/lib/psych/visitors.rb
@ -0,0 +1,5 @@
+require 'psych/visitors/visitor'
+require 'psych/visitors/to_ruby'
+require 'psych/visitors/emitter'
+require 'psych/visitors/yaml_tree'
+require 'psych/visitors/json_tree'
--- a/lib/psych/visitors/emitter.rb
+++ b/lib/psych/visitors/emitter.rb
@ -0,0 +1,41 @@
+module Psych
+  module Visitors
+    class Emitter < Psych::Visitors::Visitor
+      def initialize io
+        @handler = Psych::Emitter.new io
+      end
+
+      def visit_Psych_Nodes_Stream o
+        @handler.start_stream o.encoding
+        o.children.each { |c| accept c }
+        @handler.end_stream
+      end
+
+      def visit_Psych_Nodes_Document o
+        @handler.start_document o.version, o.tag_directives, o.implicit
+        o.children.each { |c| accept c }
+        @handler.end_document o.implicit_end
+      end
+
+      def visit_Psych_Nodes_Scalar o
+        @handler.scalar o.value, o.anchor, o.tag, o.plain, o.quoted, o.style
+      end
+
+      def visit_Psych_Nodes_Sequence o
+        @handler.start_sequence o.anchor, o.tag, o.implicit, o.style
+        o.children.each { |c| accept c }
+        @handler.end_sequence
+      end
+
+      def visit_Psych_Nodes_Mapping o
+        @handler.start_mapping o.anchor, o.tag, o.implicit, o.style
+        o.children.each { |c| accept c }
+        @handler.end_mapping
+      end
+
+      def visit_Psych_Nodes_Alias o
+        @handler.alias o.anchor
+      end
+    end
+  end
+end
--- a/lib/psych/visitors/json_tree.rb
+++ b/lib/psych/visitors/json_tree.rb
@ -0,0 +1,37 @@
+module Psych
+  module Visitors
+    class JSONTree < YAMLTree
+      def visit_Symbol o
+        append create_scalar o.to_s
+      end
+
+      def visit_NilClass o
+        scalar = Nodes::Scalar.new(
+          'null', nil, nil, true, false, Nodes::Scalar::PLAIN)
+        append scalar
+      end
+
+      private
+      def create_document
+        doc = super
+        doc.implicit     = true
+        doc.implicit_end = true
+        doc
+      end
+
+      def create_mapping
+        map = super
+        map.style = Nodes::Mapping::FLOW
+        map
+      end
+
+      def create_scalar value, anchor = nil, tag = nil, plain = false, quoted = true, style = Nodes::Scalar::ANY
+        super(value, anchor, tag, false, true, style)
+      end
+
+      def create_sequence anchor = nil, tag = nil, implicit = true, style = Nodes::Sequence::FLOW
+        super
+      end
+    end
+  end
+end
--- a/lib/psych/visitors/to_ruby.rb
+++ b/lib/psych/visitors/to_ruby.rb
@ -0,0 +1,252 @@
+require 'psych/scalar_scanner'
+
+module Psych
+  module Visitors
+    ###
+    # This class walks a YAML AST, converting each node to ruby
+    class ToRuby < Psych::Visitors::Visitor
+      def initialize
+        super
+        @st = {}
+        @ss = ScalarScanner.new
+        @domain_types = Psych.domain_types
+      end
+
+      def accept target
+        result = super
+        return result if @domain_types.empty? || !target.tag
+
+        short_name = target.tag.sub(/^!/, '').split('/', 2).last
+        if Psych.domain_types.key? short_name
+          url, block = Psych.domain_types[short_name]
+          return block.call "#{url}:#{short_name}", result
+        end
+
+        result
+      end
+
+      def visit_Psych_Nodes_Scalar o
+        @st[o.anchor] = o.value if o.anchor
+
+        if klass = Psych.load_tags[o.tag]
+          instance = klass.allocate
+
+          if instance.respond_to?(:init_with)
+            coder = Psych::Coder.new(o.tag)
+            coder.scalar = o.value
+            instance.init_with coder
+          end
+
+          return instance
+        end
+
+        return o.value if o.quoted
+        return @ss.tokenize(o.value) unless o.tag
+
+        case o.tag
+        when '!binary', 'tag:yaml.org,2002:binary'
+          o.value.unpack('m').first
+        when '!str', 'tag:yaml.org,2002:str'
+          o.value
+        when "!ruby/object:Complex"
+          Complex(o.value)
+        when "!ruby/object:Rational"
+          Rational(o.value)
+        when "tag:yaml.org,2002:float", "!float"
+          Float(@ss.tokenize(o.value))
+        when "!ruby/regexp"
+          o.value =~ /^\/(.*)\/([mix]*)$/
+          source  = $1
+          options = 0
+          lang    = nil
+          ($2 || '').split('').each do |option|
+            case option
+            when 'x' then options |= Regexp::EXTENDED
+            when 'i' then options |= Regexp::IGNORECASE
+            when 'm' then options |= Regexp::MULTILINE
+            else lang = option
+            end
+          end
+          Regexp.new(*[source, options, lang].compact)
+        when "!ruby/range"
+          args = o.value.split(/([.]{2,3})/, 2).map { |s|
+            accept Nodes::Scalar.new(s)
+          }
+          args.push(args.delete_at(1) == '...')
+          Range.new(*args)
+        when /^!ruby\/sym(bol)?:?(.*)?$/
+          o.value.to_sym
+        else
+          @ss.tokenize o.value
+        end
+      end
+
+      def visit_Psych_Nodes_Sequence o
+        if klass = Psych.load_tags[o.tag]
+          instance = klass.allocate
+
+          if instance.respond_to?(:init_with)
+            coder = Psych::Coder.new(o.tag)
+            coder.seq = o.children.map { |c| accept c }
+            instance.init_with coder
+          end
+
+          return instance
+        end
+
+        case o.tag
+        when '!omap', 'tag:yaml.org,2002:omap'
+          map = Psych::Omap.new
+          @st[o.anchor] = map if o.anchor
+          o.children.each { |a|
+            map[accept(a.children.first)] = accept a.children.last
+          }
+          map
+        else
+          list = []
+          @st[o.anchor] = list if o.anchor
+          o.children.each { |c| list.push accept c }
+          list
+        end
+      end
+
+      def visit_Psych_Nodes_Mapping o
+        return revive(Psych.load_tags[o.tag], o) if Psych.load_tags[o.tag]
+
+        case o.tag
+        when '!str', 'tag:yaml.org,2002:str'
+          members = Hash[*o.children.map { |c| accept c }]
+          string = members.delete 'str'
+          init_with(string, members.map { |k,v| [k.to_s.sub(/^@/, ''),v] }, o)
+        when /^!ruby\/struct:?(.*)?$/
+          klass = resolve_class($1)
+
+          if klass
+            s = klass.allocate
+            @st[o.anchor] = s if o.anchor
+
+            members = {}
+            struct_members = s.members.map { |x| x.to_sym }
+            o.children.each_slice(2) do |k,v|
+              member = accept(k)
+              value  = accept(v)
+              if struct_members.include?(member.to_sym)
+                s.send("#{member}=", value)
+              else
+                members[member.to_s.sub(/^@/, '')] = value
+              end
+            end
+            init_with(s, members, o)
+          else
+            members = o.children.map { |c| accept c }
+            h = Hash[*members]
+            Struct.new(*h.map { |k,v| k.to_sym }).new(*h.map { |k,v| v })
+          end
+
+        when '!ruby/range'
+          h = Hash[*o.children.map { |c| accept c }]
+          Range.new(h['begin'], h['end'], h['excl'])
+
+        when /^!ruby\/exception:?(.*)?$/
+          h = Hash[*o.children.map { |c| accept c }]
+
+          e = build_exception((resolve_class($1) || Exception),
+                              h.delete('message'))
+          init_with(e, h, o)
+
+        when '!set', 'tag:yaml.org,2002:set'
+          set = Psych::Set.new
+          @st[o.anchor] = set if o.anchor
+          o.children.each_slice(2) do |k,v|
+            set[accept(k)] = accept(v)
+          end
+          set
+
+        when '!ruby/object:Complex'
+          h = Hash[*o.children.map { |c| accept c }]
+          Complex(h['real'], h['image'])
+
+        when '!ruby/object:Rational'
+          h = Hash[*o.children.map { |c| accept c }]
+          Rational(h['numerator'], h['denominator'])
+
+        when /^!ruby\/object:?(.*)?$/
+          name = $1 || 'Object'
+          obj = revive((resolve_class(name) || Object), o)
+          @st[o.anchor] = obj if o.anchor
+          obj
+        else
+          hash = {}
+          @st[o.anchor] = hash if o.anchor
+
+          o.children.each_slice(2) { |k,v|
+            key = accept(k)
+
+            if key == '<<' && Nodes::Alias === v
+              # FIXME: remove this when "<<" syntax is deprecated
+              if $VERBOSE
+                where = caller.find { |x| x !~ /psych/ }
+                warn where
+                warn "\"<<: *#{v.anchor}\" is no longer supported, please switch to \"*#{v.anchor}\""
+              end
+              return accept(v)
+            else
+              hash[key] = accept(v)
+            end
+
+          }
+          hash
+        end
+      end
+
+      def visit_Psych_Nodes_Document o
+        accept o.root
+      end
+
+      def visit_Psych_Nodes_Stream o
+        o.children.map { |c| accept c }
+      end
+
+      def visit_Psych_Nodes_Alias o
+        @st[o.anchor]
+      end
+
+      private
+      def revive klass, node
+        s = klass.allocate
+        h = Hash[*node.children.map { |c| accept c }]
+        init_with(s, h, node)
+      end
+
+      def init_with o, h, node
+        if o.respond_to?(:init_with)
+          c = Psych::Coder.new(node.tag)
+          c.map = h
+          o.init_with c
+        else
+          h.each { |k,v| o.instance_variable_set(:"@#{k}", v) }
+        end
+        o
+      end
+
+      # Convert +klassname+ to a Class
+      def resolve_class klassname
+        return nil unless klassname and not klassname.empty?
+
+        name    = klassname
+        retried = false
+
+        begin
+          path2class(name)
+        rescue ArgumentError => ex
+          name    = "Struct::#{name}"
+          unless retried
+            retried = true
+            retry
+          end
+          raise ex
+        end
+      end
+    end
+  end
+end
--- a/lib/psych/visitors/visitor.rb
+++ b/lib/psych/visitors/visitor.rb
@ -0,0 +1,18 @@
+module Psych
+  module Visitors
+    class Visitor
+      def accept target
+        case target
+        when Psych::Nodes::Scalar   then visit_Psych_Nodes_Scalar target
+        when Psych::Nodes::Mapping  then visit_Psych_Nodes_Mapping target
+        when Psych::Nodes::Sequence then visit_Psych_Nodes_Sequence target
+        when Psych::Nodes::Alias    then visit_Psych_Nodes_Alias target
+        when Psych::Nodes::Document then visit_Psych_Nodes_Document target
+        when Psych::Nodes::Stream   then visit_Psych_Nodes_Stream target
+        else
+          raise "Can't handle #{target}"
+        end
+      end
+    end
+  end
+end
--- a/lib/psych/visitors/yaml_tree.rb
+++ b/lib/psych/visitors/yaml_tree.rb
@ -0,0 +1,312 @@
+module Psych
+  module Visitors
+    class YAMLTree < Psych::Visitors::Visitor
+      attr_reader :tree
+
+      def initialize options = {}
+        super()
+        @json  = options[:json]
+        @tree  = Nodes::Stream.new
+        @stack = []
+        @st    = {}
+        @ss    = ScalarScanner.new
+
+        @dispatch_cache = Hash.new do |h,klass|
+          method = "visit_#{(klass.name || '').split('::').join('_')}"
+
+          method = respond_to?(method) ? method : h[klass.superclass]
+
+          raise(TypeError, "Can't dump #{target.class}") unless method
+
+          h[klass] = method
+        end
+      end
+
+      def << object
+        doc = create_document
+        @stack << doc
+        @tree.children << doc
+        accept object
+      end
+
+      def accept target
+        # return any aliases we find
+        if node = @st[target.object_id]
+          node.anchor = target.object_id.to_s
+          return append Nodes::Alias.new target.object_id.to_s
+        end
+
+        if target.respond_to?(:encode_with)
+          dump_coder target
+        else
+          send(@dispatch_cache[target.class], target)
+        end
+      end
+
+      def visit_Psych_Omap o
+        seq = Nodes::Sequence.new(nil, '!omap', false)
+        register(o, seq)
+
+        @stack.push append seq
+        o.each { |k,v| visit_Hash k => v }
+        @stack.pop
+      end
+
+      def visit_Object o
+        tag = Psych.dump_tags[o.class]
+        unless tag
+          klass = o.class == Object ? nil : o.class.name
+          tag   = ['!ruby/object', klass].compact.join(':')
+        end
+
+        map = append Nodes::Mapping.new(nil, tag, false)
+        register(o, map)
+
+        @stack.push map
+        dump_ivars(o, map)
+        @stack.pop
+      end
+
+      def visit_Struct o
+        tag = ['!ruby/struct', o.class.name].compact.join(':')
+
+        map = register(o, Nodes::Mapping.new(nil, tag, false))
+
+        @stack.push append map
+
+        o.members.each do |member|
+          map.children <<  Nodes::Scalar.new("#{member}")
+          accept o[member]
+        end
+
+        dump_ivars(o, map)
+
+        @stack.pop
+      end
+
+      def visit_Exception o
+        tag = ['!ruby/exception', o.class.name].join ':'
+
+        map = append Nodes::Mapping.new(nil, tag, false)
+
+        @stack.push map
+
+        {
+          'message'   => private_iv_get(o, 'mesg'),
+          'backtrace' => private_iv_get(o, 'backtrace'),
+        }.each do |k,v|
+          next unless v
+          map.children << Nodes::Scalar.new(k)
+          accept v
+        end
+
+        dump_ivars(o, map)
+
+        @stack.pop
+      end
+
+      def visit_Regexp o
+        append Nodes::Scalar.new(o.inspect, nil, '!ruby/regexp', false)
+      end
+
+      def visit_Time o
+        formatted = o.strftime("%Y-%m-%d %H:%M:%S")
+        if o.utc?
+          formatted += ".%06dZ" % [o.usec]
+        else
+          formatted += ".%06d %+.2d:00" % [o.usec, o.gmt_offset / 3600]
+        end
+
+        append Nodes::Scalar.new formatted
+      end
+
+      def visit_Rational o
+        map = append Nodes::Mapping.new(nil, '!ruby/object:Rational', false)
+        [
+          'denominator', o.denominator.to_s,
+          'numerator', o.numerator.to_s
+        ].each do |m|
+          map.children << Nodes::Scalar.new(m)
+        end
+      end
+
+      def visit_Complex o
+        map = append Nodes::Mapping.new(nil, '!ruby/object:Complex', false)
+
+        ['real', o.real.to_s, 'image', o.imag.to_s].each do |m|
+          map.children << Nodes::Scalar.new(m)
+        end
+      end
+
+      def visit_Integer o
+        append Nodes::Scalar.new o.to_s
+      end
+      alias :visit_TrueClass :visit_Integer
+      alias :visit_FalseClass :visit_Integer
+      alias :visit_Date :visit_Integer
+
+      def visit_Float o
+        if o.nan?
+          append Nodes::Scalar.new '.nan'
+        elsif o.infinite?
+          append Nodes::Scalar.new(o.infinite? > 0 ? '.inf' : '-.inf')
+        else
+          append Nodes::Scalar.new o.to_s
+        end
+      end
+
+      def visit_String o
+        plain = false
+        quote = false
+
+        if o.index("\x00") || o.count("^ -~\t\r\n").fdiv(o.length) > 0.3
+          str   = [o].pack('m').chomp
+          tag   = '!binary'
+        else
+          str   = o
+          tag   = nil
+          quote = !(String === @ss.tokenize(o))
+          plain = !quote
+        end
+
+        ivars = o.respond_to?(:to_yaml_properties) ?
+          o.to_yaml_properties :
+          o.instance_variables
+
+        scalar = create_scalar str, nil, tag, plain, quote
+
+        if ivars.empty?
+          append scalar
+        else
+          mapping = append Nodes::Mapping.new(nil, '!str', false)
+
+          mapping.children << Nodes::Scalar.new('str')
+          mapping.children << scalar
+
+          @stack.push mapping
+          dump_ivars o, mapping
+          @stack.pop
+        end
+      end
+
+      def visit_Class o
+        raise TypeError, "can't dump anonymous class #{o.class}"
+      end
+
+      def visit_Range o
+        @stack.push append Nodes::Mapping.new(nil, '!ruby/range', false)
+        ['begin', o.begin, 'end', o.end, 'excl', o.exclude_end?].each do |m|
+          accept m
+        end
+        @stack.pop
+      end
+
+      def visit_Hash o
+        @stack.push append register(o, create_mapping)
+
+        o.each do |k,v|
+          accept k
+          accept v
+        end
+
+        @stack.pop
+      end
+
+      def visit_Psych_Set o
+        @stack.push append register(o, Nodes::Mapping.new(nil, '!set', false))
+
+        o.each do |k,v|
+          accept k
+          accept v
+        end
+
+        @stack.pop
+      end
+
+      def visit_Array o
+        @stack.push append register(o, create_sequence)
+        o.each { |c| accept c }
+        @stack.pop
+      end
+
+      def visit_NilClass o
+        append Nodes::Scalar.new('', nil, 'tag:yaml.org,2002:null', false)
+      end
+
+      def visit_Symbol o
+        append create_scalar ":#{o}"
+      end
+
+      private
+      def append o
+        @stack.last.children << o
+        o
+      end
+
+      def register target, yaml_obj
+        @st[target.object_id] = yaml_obj
+        yaml_obj
+      end
+
+      def dump_coder o
+        tag = Psych.dump_tags[o.class]
+        unless tag
+          klass = o.class == Object ? nil : o.class.name
+          tag   = ['!ruby/object', klass].compact.join(':')
+        end
+
+        c = Psych::Coder.new(tag)
+        o.encode_with(c)
+        emit_coder c
+      end
+
+      def emit_coder c
+        case c.type
+        when :scalar
+          append create_scalar(c.scalar, nil, c.tag, c.tag.nil?)
+        when :seq
+          @stack.push append create_sequence(nil, c.tag, c.tag.nil?)
+          c.seq.each do |thing|
+            accept thing
+          end
+          @stack.pop
+        when :map
+          map = append Nodes::Mapping.new(nil, c.tag, c.implicit, c.style)
+          @stack.push map
+          c.map.each do |k,v|
+            map.children << create_scalar(k)
+            accept v
+          end
+          @stack.pop
+        end
+      end
+
+      def dump_ivars target, map
+        ivars = target.respond_to?(:to_yaml_properties) ?
+          target.to_yaml_properties :
+          target.instance_variables
+
+        ivars.each do |iv|
+          map.children << create_scalar("#{iv.to_s.sub(/^@/, '')}")
+          accept target.instance_variable_get(iv)
+        end
+      end
+
+      def create_document
+        Nodes::Document.new
+      end
+
+      def create_mapping
+        Nodes::Mapping.new
+      end
+
+      def create_scalar value, anchor = nil, tag = nil, plain = true, quoted = false, style = Nodes::Scalar::ANY
+        Nodes::Scalar.new(value, anchor, tag, plain, quoted, style)
+      end
+
+      def create_sequence anchor = nil, tag = nil, implicit = true, style = Nodes::Sequence::BLOCK
+        Nodes::Sequence.new(anchor, tag, implicit, style)
+      end
+    end
+  end
+end
--- a/test/psych/helper.rb
+++ b/test/psych/helper.rb
@ -0,0 +1,63 @@
+require 'minitest/autorun'
+require 'stringio'
+require 'tempfile'
+require 'date'
+
+module Psych
+  class TestCase < MiniTest::Unit::TestCase
+    #
+    # Convert between Psych and the object to verify correct parsing and
+    # emitting
+    #
+    def assert_to_yaml( obj, yaml )
+      assert_equal( obj, Psych::load( yaml ) )
+      assert_equal( obj, Psych::parse( yaml ).transform )
+      assert_equal( obj, Psych::load( obj.psych_to_yaml ) )
+      assert_equal( obj, Psych::parse( obj.psych_to_yaml ).transform )
+      assert_equal( obj, Psych::load(
+        obj.psych_to_yaml(
+          :UseVersion => true, :UseHeader => true, :SortKeys => true
+        )
+      ))
+    end
+
+    #
+    # Test parser only
+    #
+    def assert_parse_only( obj, yaml )
+      assert_equal( obj, Psych::load( yaml ) )
+      assert_equal( obj, Psych::parse( yaml ).transform )
+    end
+
+    def assert_cycle( obj )
+      v = Visitors::YAMLTree.new
+      v << obj
+      assert_equal(obj, Psych.load(v.tree.to_yaml))
+      assert_equal( obj, Psych::load(Psych.dump(obj)))
+      assert_equal( obj, Psych::load( obj.psych_to_yaml ) )
+    end
+
+    #
+    # Make a time with the time zone
+    #
+    def mktime( year, mon, day, hour, min, sec, usec, zone = "Z" )
+      usec = Rational(usec.to_s) * 1000000
+      val = Time::utc( year.to_i, mon.to_i, day.to_i, hour.to_i, min.to_i, sec.to_i, usec )
+      if zone != "Z"
+        hour = zone[0,3].to_i * 3600
+        min = zone[3,2].to_i * 60
+        ofs = (hour + min)
+        val = Time.at( val.tv_sec - ofs, val.tv_nsec / 1000.0 )
+      end
+      return val
+    end
+  end
+end
+
+require 'psych'
+
+# FIXME: remove this when syck is removed
+o = Object.new
+a = o.method(:psych_to_yaml)
+b = o.method(:to_yaml)
+raise "psych should define to_yaml" unless a == b
--- a/test/psych/test_alias_and_anchor.rb
+++ b/test/psych/test_alias_and_anchor.rb
@ -0,0 +1,26 @@
+require 'test/psych/helper'
+
+module Psych
+ class TestAliasAndAnchor < TestCase
+   def test_mri_compatibility
+     yaml = <<EOYAML
+---
+- &id001 !ruby/object {}
+
+- *id001
+- *id001
+EOYAML
+     result = Psych.load yaml
+     result.each {|el| assert_same(result[0], el) }
+   end
+
+   def test_anchor_alias_round_trip
+     o = Object.new
+     original = [o,o,o]
+
+     yaml = Psych.dump original
+     result = Psych.load yaml
+     result.each {|el| assert_same(result[0], el) }
+   end
+ end
+end
--- a/test/psych/test_array.rb
+++ b/test/psych/test_array.rb
@ -0,0 +1,19 @@
+require 'test/psych/helper'
+
+module Psych
+  class TestArray < TestCase
+    def setup
+      super
+      @list = [{ :a => 'b' }, 'foo']
+    end
+
+    def test_self_referential
+      @list << @list
+      assert_cycle(@list)
+    end
+
+    def test_cycle
+      assert_cycle(@list)
+    end
+  end
+end
--- a/test/psych/test_boolean.rb
+++ b/test/psych/test_boolean.rb
@ -0,0 +1,36 @@
+require 'test/psych/helper'
+
+module Psych
+  ###
+  # Test booleans from YAML spec:
+  # http://yaml.org/type/bool.html
+  class TestBoolean < TestCase
+    %w{ yes Yes YES true True TRUE on On ON }.each do |truth|
+      define_method(:"test_#{truth}") do
+        assert_equal true, Psych.load("--- #{truth}")
+      end
+    end
+
+    %w{ no No NO false False FALSE off Off OFF }.each do |truth|
+      define_method(:"test_#{truth}") do
+        assert_equal false, Psych.load("--- #{truth}")
+      end
+    end
+
+    ###
+    # YAML spec says "y" and "Y" may be used as true, but Syck treats them
+    # as literal strings
+    def test_y
+      assert_equal "y", Psych.load("--- y")
+      assert_equal "Y", Psych.load("--- Y")
+    end
+
+    ###
+    # YAML spec says "n" and "N" may be used as false, but Syck treats them
+    # as literal strings
+    def test_n
+      assert_equal "n", Psych.load("--- n")
+      assert_equal "N", Psych.load("--- N")
+    end
+  end
+end
--- a/test/psych/test_class.rb
+++ b/test/psych/test_class.rb
@ -0,0 +1,17 @@
+require 'test/psych/helper'
+
+module Psych
+  class TestClass < TestCase
+    def test_cycle
+      assert_raises(::TypeError) do
+        assert_cycle(TestClass)
+      end
+    end
+
+    def test_dump
+      assert_raises(::TypeError) do
+        Psych.dump TestClass
+      end
+    end
+  end
+end
--- a/test/psych/test_coder.rb
+++ b/test/psych/test_coder.rb
@ -0,0 +1,144 @@
+require 'test/psych/helper'
+
+module Psych
+  class TestCoder < TestCase
+    class InitApi
+      attr_accessor :implicit
+      attr_accessor :style
+      attr_accessor :tag
+      attr_accessor :a, :b, :c
+
+      def initialize
+        @a = 1
+        @b = 2
+        @c = 3
+      end
+
+      def init_with coder
+        @a = coder['aa']
+        @b = coder['bb']
+        @implicit = coder.implicit
+        @tag      = coder.tag
+        @style    = coder.style
+      end
+
+      def encode_with coder
+        coder['aa'] = @a
+        coder['bb'] = @b
+      end
+    end
+
+    class TaggingCoder < InitApi
+      def encode_with coder
+        super
+        coder.tag       = coder.tag.sub(/!/, '!hello')
+        coder.implicit  = false
+        coder.style     = Psych::Nodes::Mapping::FLOW
+      end
+    end
+
+    class ScalarCoder
+      def encode_with coder
+        coder.scalar = "foo"
+      end
+    end
+
+    class Represent
+      yaml_tag 'foo'
+      def encode_with coder
+        coder.represent_scalar 'foo', 'bar'
+      end
+    end
+
+    class RepresentWithInit
+      yaml_tag name
+      attr_accessor :str
+
+      def init_with coder
+        @str = coder.scalar
+      end
+
+      def encode_with coder
+        coder.represent_scalar self.class.name, 'bar'
+      end
+    end
+
+    class RepresentWithSeq
+      yaml_tag name
+      attr_accessor :seq
+
+      def init_with coder
+        @seq = coder.seq
+      end
+
+      def encode_with coder
+        coder.represent_seq self.class.name, %w{ foo bar }
+      end
+    end
+
+    class RepresentWithMap
+      yaml_tag name
+      attr_accessor :map
+
+      def init_with coder
+        @map = coder.map
+      end
+
+      def encode_with coder
+        coder.represent_map self.class.name, { 'a' => 'b' }
+      end
+    end
+
+    def test_represent_map
+      thing = Psych.load(Psych.dump(RepresentWithMap.new))
+      assert_equal({ 'a' => 'b' }, thing.map)
+    end
+
+    def test_represent_sequence
+      thing = Psych.load(Psych.dump(RepresentWithSeq.new))
+      assert_equal %w{ foo bar }, thing.seq
+    end
+
+    def test_represent_with_init
+      thing = Psych.load(Psych.dump(RepresentWithInit.new))
+      assert_equal 'bar', thing.str
+    end
+
+    def test_represent!
+      assert_match(/foo/, Psych.dump(Represent.new))
+      assert_instance_of(Represent, Psych.load(Psych.dump(Represent.new)))
+    end
+
+    def test_scalar_coder
+      foo = Psych.load(Psych.dump(ScalarCoder.new))
+      assert_equal 'foo', foo
+    end
+
+    def test_load_dumped_tagging
+      foo = InitApi.new
+      bar = Psych.load(Psych.dump(foo))
+      assert_equal false, bar.implicit
+      assert_equal "!ruby/object:Psych::TestCoder::InitApi", bar.tag
+      assert_equal Psych::Nodes::Mapping::BLOCK, bar.style
+    end
+
+    def test_dump_with_tag
+      foo = TaggingCoder.new
+      assert_match(/hello/, Psych.dump(foo))
+      assert_match(/\{aa/, Psych.dump(foo))
+    end
+
+    def test_dump_encode_with
+      foo = InitApi.new
+      assert_match(/aa/, Psych.dump(foo))
+    end
+
+    def test_dump_init_with
+      foo = InitApi.new
+      bar = Psych.load(Psych.dump(foo))
+      assert_equal foo.a, bar.a
+      assert_equal foo.b, bar.b
+      assert_nil bar.c
+    end
+  end
+end
--- a/test/psych/test_document.rb
+++ b/test/psych/test_document.rb
@ -0,0 +1,46 @@
+require 'test/psych/helper'
+
+module Psych
+  class TestDocument < TestCase
+    def setup
+      super
+      @stream = Psych.parse_stream(<<-eoyml)
+%YAML 1.1
+%TAG ! tag:tenderlovemaking.com,2009:
+--- !fun
+      eoyml
+      @doc = @stream.children.first
+    end
+
+    def test_parse_tag
+      assert_equal([['!', 'tag:tenderlovemaking.com,2009:']],
+        @doc.tag_directives)
+    end
+
+    def test_emit_tag
+      assert_match('%TAG ! tag:tenderlovemaking.com,2009:', @stream.to_yaml)
+    end
+
+    def test_emit_multitag
+      @doc.tag_directives << ['!!', 'foo.com,2009:']
+      yaml = @stream.to_yaml
+      assert_match('%TAG ! tag:tenderlovemaking.com,2009:', yaml)
+      assert_match('%TAG !! foo.com,2009:', yaml)
+    end
+
+    def test_emit_bad_tag
+      assert_raises(RuntimeError) do
+        @doc.tag_directives = [['!']]
+        @stream.to_yaml
+      end
+    end
+
+    def test_parse_version
+      assert_equal([1,1], @doc.version)
+    end
+
+    def test_emit_version
+      assert_match('%YAML 1.1', @stream.to_yaml)
+    end
+  end
+end
--- a/test/psych/test_emitter.rb
+++ b/test/psych/test_emitter.rb
@ -0,0 +1,87 @@
+# -*- coding: utf-8 -*-
+
+require 'test/psych/helper'
+
+module Psych
+  class TestEmitter < TestCase
+    def setup
+      super
+      @out = StringIO.new
+      @emitter = Psych::Emitter.new @out
+    end
+
+    def test_set_canonical
+      @emitter.canonical = true
+      assert_equal true, @emitter.canonical
+
+      @emitter.canonical = false
+      assert_equal false, @emitter.canonical
+    end
+
+    def test_indentation_set
+      assert_equal 2, @emitter.indentation
+      @emitter.indentation = 5
+      assert_equal 5, @emitter.indentation
+    end
+
+    def test_emit_utf_8
+      @emitter.start_stream Psych::Nodes::Stream::UTF8
+      @emitter.start_document [], [], false
+      @emitter.scalar '日本語', nil, nil, false, true, 1
+      @emitter.end_document true
+      @emitter.end_stream
+      assert_match('日本語', @out.string)
+    end
+
+    def test_start_stream_arg_error
+      assert_raises(TypeError) do
+        @emitter.start_stream 'asdfasdf'
+      end
+    end
+
+    def test_start_doc_arg_error
+      @emitter.start_stream Psych::Nodes::Stream::UTF8
+
+      [
+        [nil, [], false],
+        [[nil, nil], [], false],
+        [[], 'foo', false],
+        [[], ['foo'], false],
+        [[], [nil,nil], false],
+      ].each do |args|
+        assert_raises(TypeError) do
+          @emitter.start_document(*args)
+        end
+      end
+    end
+
+    def test_scalar_arg_error
+      @emitter.start_stream Psych::Nodes::Stream::UTF8
+      @emitter.start_document [], [], false
+
+      [
+        [:foo, nil, nil, false, true, 1],
+        ['foo', Object.new, nil, false, true, 1],
+        ['foo', nil, Object.new, false, true, 1],
+        ['foo', nil, nil, false, true, :foo],
+      ].each do |args|
+        assert_raises(TypeError) do
+          @emitter.scalar(*args)
+        end
+      end
+    end
+
+    def test_start_sequence_arg_error
+      @emitter.start_stream Psych::Nodes::Stream::UTF8
+      @emitter.start_document [], [], false
+
+      assert_raises(TypeError) do
+        @emitter.start_sequence(nil, Object.new, true, 1)
+      end
+
+      assert_raises(TypeError) do
+        @emitter.start_sequence(nil, nil, true, :foo)
+      end
+    end
+  end
+end
--- a/test/psych/test_encoding.rb
+++ b/test/psych/test_encoding.rb
@ -0,0 +1,91 @@
+# -*- coding: utf-8 -*-
+
+require 'test/psych/helper'
+
+module Psych
+  class TestEncoding < TestCase
+    class EncodingCatcher < Handler
+      attr_reader :strings
+      def initialize
+        @strings = []
+      end
+
+      (Handler.instance_methods(true) -
+       Object.instance_methods).each do |m|
+        class_eval %{
+          def #{m} *args
+            @strings += args.flatten.find_all { |a|
+              String === a
+            }
+          end
+        }
+      end
+    end
+
+    def setup
+      super
+      @handler = EncodingCatcher.new
+      @parser  = Psych::Parser.new @handler
+      @utf8    = Encoding.find('UTF-8')
+    end
+
+    def test_scalar
+      @parser.parse("--- a")
+      assert_encodings @utf8, @handler.strings
+    end
+
+    def test_alias
+      @parser.parse(<<-eoyml)
+%YAML 1.1
+---
+!!seq [
+  !!str "Without properties",
+  &A !!str "Anchored",
+  !!str "Tagged",
+  *A,
+  !!str "",
+]
+      eoyml
+      assert_encodings @utf8, @handler.strings
+    end
+
+    def test_list_anchor
+      list = %w{ a b }
+      list << list
+      @parser.parse(Psych.dump(list))
+      assert_encodings @utf8, @handler.strings
+    end
+
+    def test_map_anchor
+      h = {}
+      h['a'] = h
+      @parser.parse(Psych.dump(h))
+      assert_encodings @utf8, @handler.strings
+    end
+
+    def test_map_tag
+      @parser.parse(<<-eoyml)
+%YAML 1.1
+---
+!!map { a : b }
+      eoyml
+      assert_encodings @utf8, @handler.strings
+    end
+
+    def test_doc_tag
+      @parser.parse(<<-eoyml)
+%YAML 1.1
+%TAG ! tag:tenderlovemaking.com,2009:
+--- !fun
+      eoyml
+      assert_encodings @utf8, @handler.strings
+    end
+
+    private
+    def assert_encodings encoding, strings
+      strings.each do |str|
+        assert_equal encoding, str.encoding, str
+      end
+    end
+  end
+end
--- a/test/psych/test_exception.rb
+++ b/test/psych/test_exception.rb
@ -0,0 +1,39 @@
+require 'test/psych/helper'
+
+module Psych
+  class TestException < TestCase
+    class Wups < Exception
+      attr_reader :foo, :bar
+      def initialize *args
+        super
+        @foo = 1
+        @bar = 2
+      end
+    end
+
+    def setup
+      super
+      @wups = Wups.new
+    end
+
+    def test_convert
+      w = Psych.load(Psych.dump(@wups))
+      assert_equal @wups, w
+      assert_equal 1, w.foo
+      assert_equal 2, w.bar
+    end
+
+    def test_to_yaml_properties
+      class << @wups
+        def to_yaml_properties
+          [:@foo]
+        end
+      end
+
+      w = Psych.load(Psych.dump(@wups))
+      assert_equal @wups, w
+      assert_equal 1, w.foo
+      assert_nil w.bar
+    end
+  end
+end
--- a/test/psych/test_hash.rb
+++ b/test/psych/test_hash.rb
@ -0,0 +1,30 @@
+require 'test/psych/helper'
+
+module Psych
+  class TestHash < TestCase
+    def setup
+      super
+      @hash = { :a => 'b' }
+    end
+
+    def test_self_referential
+      @hash['self'] = @hash
+      assert_cycle(@hash)
+    end
+
+    def test_cycles
+      assert_cycle(@hash)
+    end
+
+    def test_ref_append
+      hash = Psych.load(<<-eoyml)
+---
+foo: &foo
+  hello: world
+bar:
+  <<: *foo
+eoyml
+      assert_equal({"foo"=>{"hello"=>"world"}, "bar"=>{"hello"=>"world"}}, hash)
+    end
+  end
+end
--- a/test/psych/test_json_tree.rb
+++ b/test/psych/test_json_tree.rb
@ -0,0 +1,43 @@
+require 'test/psych/helper'
+
+module Psych
+  class TestJSONTree < TestCase
+    def test_string
+      assert_match(/(['"])foo\1/, Psych.to_json("foo"))
+    end
+
+    def test_symbol
+      assert_match(/(['"])foo\1/, Psych.to_json(:foo))
+    end
+
+    def test_nil
+      assert_match(/^null/, Psych.to_json(nil))
+    end
+
+    def test_int
+      assert_match(/^10/, Psych.to_json(10))
+    end
+
+    def test_float
+      assert_match(/^1.2/, Psych.to_json(1.2))
+    end
+
+    def test_hash
+      hash = { 'one' => 'two' }
+      json = Psych.to_json(hash)
+      assert_match(/}$/, json)
+      assert_match(/^\{/, json)
+      assert_match(/['"]one['"]/, json)
+      assert_match(/['"]two['"]/, json)
+    end
+
+    def test_list_to_json
+      list = %w{ one two }
+      json = Psych.to_json(list)
+      assert_match(/]$/, json)
+      assert_match(/^\[/, json)
+      assert_match(/['"]one['"]/, json)
+      assert_match(/['"]two['"]/, json)
+    end
+  end
+end
--- a/test/psych/test_null.rb
+++ b/test/psych/test_null.rb
@ -0,0 +1,19 @@
+require 'test/psych/helper'
+
+module Psych
+  ###
+  # Test null from YAML spec:
+  # http://yaml.org/type/null.html
+  class TestNull < TestCase
+    def test_null_list
+      assert_equal [nil] * 5, Psych.load(<<-eoyml)
+---
+- ~
+- null
+- 
+- Null
+- NULL
+      eoyml
+    end
+  end
+end
--- a/test/psych/test_object.rb
+++ b/test/psych/test_object.rb
@ -0,0 +1,27 @@
+require 'test/psych/helper'
+
+module Psych
+  class Tagged
+    yaml_tag '!foo'
+
+    attr_accessor :baz
+
+    def initialize
+      @baz = 'bar'
+    end
+  end
+
+  class TestObject < TestCase
+    def test_dump_with_tag
+      tag = Tagged.new
+      assert_match('foo', Psych.dump(tag))
+    end
+
+    def test_tag_round_trip
+      tag   = Tagged.new
+      tag2  = Psych.load(Psych.dump(tag))
+      assert_equal tag.baz, tag2.baz
+      assert_instance_of(Tagged, tag2)
+    end
+  end
+end
--- a/test/psych/test_omap.rb
+++ b/test/psych/test_omap.rb
@ -0,0 +1,68 @@
+require 'test/psych/helper'
+
+module Psych
+  class TestOmap < TestCase
+    def test_self_referential
+      map = Psych::Omap.new
+      map['foo'] = 'bar'
+      map['self'] = map
+      assert_equal(map, Psych.load(Psych.dump(map)))
+    end
+
+    def test_keys
+      map = Psych::Omap.new
+      map['foo'] = 'bar'
+      assert_equal 'bar', map['foo']
+    end
+
+    def test_order
+      map = Psych::Omap.new
+      map['a'] = 'b'
+      map['b'] = 'c'
+      assert_equal [%w{a b}, %w{b c}], map.to_a
+    end
+
+    def test_square
+      list = [["a", "b"], ["b", "c"]]
+      map = Psych::Omap[*list.flatten]
+      assert_equal list, map.to_a
+      assert_equal 'b', map['a']
+      assert_equal 'c', map['b']
+    end
+
+    def test_dump
+      map = Psych::Omap['a', 'b', 'c', 'd']
+      yaml = Psych.dump(map)
+      assert_match('!omap', yaml)
+      assert_match('- a: b', yaml)
+      assert_match('- c: d', yaml)
+    end
+
+    def test_round_trip
+      list = [["a", "b"], ["b", "c"]]
+      map = Psych::Omap[*list.flatten]
+      assert_cycle(map)
+    end
+
+    def test_load
+      list = [["a", "b"], ["c", "d"]]
+      map = Psych.load(<<-eoyml)
+--- !omap
+- a: b
+- c: d
+      eoyml
+      assert_equal list, map.to_a
+    end
+
+    # NOTE: This test will not work with Syck
+    def test_load_shorthand
+      list = [["a", "b"], ["c", "d"]]
+      map = Psych.load(<<-eoyml)
+--- !!omap
+- a: b
+- c: d
+      eoyml
+      assert_equal list, map.to_a
+    end
+  end
+end
--- a/test/psych/test_parser.rb
+++ b/test/psych/test_parser.rb
@ -0,0 +1,188 @@
+require 'test/psych/helper'
+
+module Psych
+  class TestParser < TestCase
+    class EventCatcher < Handler
+      attr_reader :calls
+      def initialize
+        @calls = []
+      end
+
+      (Handler.instance_methods(true) -
+       Object.instance_methods).each do |m|
+        class_eval %{
+          def #{m} *args
+            super
+            @calls << [:#{m}, args]
+          end
+        }
+      end
+    end
+
+    def setup
+      super
+      @parser = Psych::Parser.new EventCatcher.new
+    end
+
+    def test_bogus_io
+      o = Object.new
+      def o.read len; self end
+
+      assert_raises(TypeError) do
+        @parser.parse o
+      end
+    end
+
+    def test_parse_io
+      @parser.parse StringIO.new("--- a")
+      assert_called :start_stream
+      assert_called :scalar
+      assert_called :end_stream
+    end
+
+    def test_syntax_error
+      assert_raises(Psych::SyntaxError) do
+        @parser.parse("---\n\"foo\"\n\"bar\"\n")
+      end
+    end
+
+    def test_mapping_end
+      @parser.parse("---\n!!map { key: value }")
+      assert_called :end_mapping
+    end
+
+    def test_mapping_tag
+      @parser.parse("---\n!!map { key: value }")
+      assert_called :start_mapping, ["tag:yaml.org,2002:map", false, Nodes::Mapping::FLOW]
+    end
+
+    def test_mapping_anchor
+      @parser.parse("---\n&A { key: value }")
+      assert_called :start_mapping, ['A', true, Nodes::Mapping::FLOW]
+    end
+
+    def test_mapping_block
+      @parser.parse("---\n  key: value")
+      assert_called :start_mapping, [true, Nodes::Mapping::BLOCK]
+    end
+
+    def test_mapping_start
+      @parser.parse("---\n{ key: value }")
+      assert_called :start_mapping
+      assert_called :start_mapping, [true, Nodes::Mapping::FLOW]
+    end
+
+    def test_sequence_end
+      @parser.parse("---\n&A [1, 2]")
+      assert_called :end_sequence
+    end
+
+    def test_sequence_start_anchor
+      @parser.parse("---\n&A [1, 2]")
+      assert_called :start_sequence, ["A", true, Nodes::Sequence::FLOW]
+    end
+
+    def test_sequence_start_tag
+      @parser.parse("---\n!!seq [1, 2]")
+      assert_called :start_sequence, ["tag:yaml.org,2002:seq", false, Nodes::Sequence::FLOW]
+    end
+
+    def test_sequence_start_flow
+      @parser.parse("---\n[1, 2]")
+      assert_called :start_sequence, [true, Nodes::Sequence::FLOW]
+    end
+
+    def test_sequence_start_block
+      @parser.parse("---\n  - 1\n  - 2")
+      assert_called :start_sequence, [true, Nodes::Sequence::BLOCK]
+    end
+
+    def test_literal_scalar
+      @parser.parse(<<-eoyml)
+%YAML 1.1
+---
+"literal\n\
+        \ttext\n"
+      eoyml
+      assert_called :scalar, ['literal text ', false, true, Nodes::Scalar::DOUBLE_QUOTED]
+    end
+
+    def test_scalar
+      @parser.parse("--- foo\n")
+      assert_called :scalar, ['foo', true, false, Nodes::Scalar::PLAIN]
+    end
+
+    def test_scalar_with_tag
+      @parser.parse("---\n!!str foo\n")
+      assert_called :scalar, ['foo', 'tag:yaml.org,2002:str', false, false, Nodes::Scalar::PLAIN]
+    end
+
+    def test_scalar_with_anchor
+      @parser.parse("---\n&A foo\n")
+      assert_called :scalar, ['foo', 'A', true, false, Nodes::Scalar::PLAIN]
+    end
+
+    def test_scalar_plain_implicit
+      @parser.parse("---\n&A foo\n")
+      assert_called :scalar, ['foo', 'A', true, false, Nodes::Scalar::PLAIN]
+    end
+
+    def test_alias
+      @parser.parse(<<-eoyml)
+%YAML 1.1
+---
+!!seq [
+  !!str "Without properties",
+  &A !!str "Anchored",
+  !!str "Tagged",
+  *A,
+  !!str "",
+]
+      eoyml
+      assert_called :alias, ['A']
+    end
+
+    def test_end_stream
+      @parser.parse("--- foo\n")
+      assert_called :end_stream
+    end
+
+    def test_start_stream
+      @parser.parse("--- foo\n")
+      assert_called :start_stream
+    end
+
+    def test_end_document_implicit
+      @parser.parse("\"foo\"\n")
+      assert_called :end_document, [true]
+    end
+
+    def test_end_document_explicit
+      @parser.parse("\"foo\"\n...")
+      assert_called :end_document, [false]
+    end
+
+    def test_start_document_version
+      @parser.parse("%YAML 1.1\n---\n\"foo\"\n")
+      assert_called :start_document, [[1,1], [], false]
+    end
+
+    def test_start_document_tag
+      @parser.parse("%TAG !yaml! tag:yaml.org,2002\n---\n!yaml!str \"foo\"\n")
+      assert_called :start_document, [[], [['!yaml!', 'tag:yaml.org,2002']], false]
+    end
+
+    def assert_called call, with = nil, parser = @parser
+      if with
+        call = parser.handler.calls.find { |x|
+          x.first == call && x.last.compact == with
+        }
+        assert(call,
+          "#{[call,with].inspect} not in #{parser.handler.calls.inspect}"
+        )
+      else
+        assert parser.handler.calls.any? { |x| x.first == call }
+      end
+    end
+  end
+end
--- a/test/psych/test_psych.rb
+++ b/test/psych/test_psych.rb
@ -0,0 +1,69 @@
+require 'test/psych/helper'
+
+class TestPsych < Psych::TestCase
+  def test_dump_stream
+    things = [22, "foo \n", {}]
+    stream = Psych.dump_stream(*things)
+    assert_equal things, Psych.load_stream(stream)
+  end
+
+  def test_simple
+    assert_equal 'foo', Psych.load("--- foo\n")
+  end
+
+  def test_libyaml_version
+    assert Psych.libyaml_version
+    assert_equal Psych.libyaml_version.join('.'), Psych::LIBYAML_VERSION
+  end
+
+  def test_load_documents
+    docs = Psych.load_documents("--- foo\n...\n--- bar\n...")
+    assert_equal %w{ foo bar }, docs
+  end
+
+  def test_parse_stream
+    docs = Psych.parse_stream("--- foo\n...\n--- bar\n...")
+    assert_equal %w{ foo bar }, docs.children.map { |x| x.transform }
+  end
+
+  def test_add_builtin_type
+    got = nil
+    Psych.add_builtin_type 'omap', do |type, val|
+      got = val
+    end
+    Psych.load('--- !omap hello')
+    assert_equal 'hello', got
+  ensure
+    Psych.remove_type 'omap'
+  end
+
+  def test_domain_types
+    got = nil
+    Psych.add_domain_type 'foo.bar,2002', 'foo' do |type, val|
+      got = val
+    end
+
+    Psych.load('--- !foo.bar,2002/foo hello')
+    assert_equal 'hello', got
+
+    Psych.load("--- !foo.bar,2002/foo\n- hello\n- world")
+    assert_equal %w{ hello world }, got
+
+    Psych.load("--- !foo.bar,2002/foo\nhello: world")
+    assert_equal({ 'hello' => 'world' }, got)
+  end
+
+  def test_load_file
+    name = File.join(Dir.tmpdir, 'yikes.yml')
+    File.open(name, 'wb') { |f| f.write('--- hello world') }
+
+    assert_equal 'hello world', Psych.load_file(name)
+  end
+
+  def test_parse_file
+    name = File.join(Dir.tmpdir, 'yikes.yml')
+    File.open(name, 'wb') { |f| f.write('--- hello world') }
+
+    assert_equal 'hello world', Psych.parse_file(name).transform
+  end
+end
--- a/test/psych/test_scalar.rb
+++ b/test/psych/test_scalar.rb
@ -0,0 +1,11 @@
+# -*- coding: utf-8 -*-
+
+require 'test/psych/helper'
+
+module Psych
+  class TestScalar < TestCase
+    def test_utf_8
+      assert_equal "日本語", Psych.load("--- 日本語")
+    end
+  end
+end
--- a/test/psych/test_scalar_scanner.rb
+++ b/test/psych/test_scalar_scanner.rb
@ -0,0 +1,70 @@
+require 'test/psych/helper'
+
+module Psych
+  class TestScalarScanner < TestCase
+    def test_scan_time
+      [ '2001-12-15T02:59:43.1Z',
+        '2001-12-14t21:59:43.10-05:00',
+        '2001-12-14 21:59:43.10 -5',
+        '2010-01-06 00:00:00 -08:00',
+        '2001-12-15 2:59:43.10',
+      ].each do |time|
+        ss = Psych::ScalarScanner.new
+        assert_instance_of Time, ss.tokenize(time)
+      end
+    end
+
+    attr_reader :ss
+
+    def setup
+      super
+      @ss = Psych::ScalarScanner.new
+    end
+
+    def test_scan_date
+      date = '1980-12-16'
+      token = @ss.tokenize date
+      assert_equal 1980, token.year
+      assert_equal 12, token.month
+      assert_equal 16, token.day
+    end
+
+    def test_scan_inf
+      assert_equal(1 / 0.0, ss.tokenize('.inf'))
+    end
+
+    def test_scan_minus_inf
+      assert_equal(-1 / 0.0, ss.tokenize('-.inf'))
+    end
+
+    def test_scan_nan
+      assert ss.tokenize('.nan').nan?
+    end
+
+    def test_scan_null
+      assert_equal nil, ss.tokenize('null')
+      assert_equal nil, ss.tokenize('~')
+      assert_equal nil, ss.tokenize('')
+    end
+
+    def test_scan_symbol
+      assert_equal :foo, ss.tokenize(':foo')
+    end
+
+    def test_scan_sexagesimal_float
+      assert_equal 685230.15, ss.tokenize('190:20:30.15')
+    end
+
+    def test_scan_sexagesimal_int
+      assert_equal 685230, ss.tokenize('190:20:30')
+    end
+
+    def test_scan_float
+      assert_equal 1.2, ss.tokenize('1.2')
+    end
+
+    def test_scan_true
+      assert_equal true, ss.tokenize('true')
+    end
+  end
+end
--- a/test/psych/test_serialize_subclasses.rb
+++ b/test/psych/test_serialize_subclasses.rb
@ -0,0 +1,38 @@
+require 'test/psych/helper'
+
+module Psych
+  class TestSerializeSubclasses < TestCase
+    class SomeObject
+      def initialize one, two
+        @one = one
+        @two = two
+      end
+
+      def == other
+        @one == other.instance_eval { @one } &&
+          @two == other.instance_eval { @two }
+      end
+    end
+
+    def test_some_object
+      so = SomeObject.new('foo', [1,2,3])
+      assert_equal so, Psych.load(Psych.dump(so))
+    end
+
+    class StructSubclass < Struct.new(:foo)
+      def initialize foo, bar
+        super(foo)
+        @bar = bar
+      end
+
+      def == other
+        super(other) && @bar == other.instance_eval{ @bar }
+      end
+    end
+
+    def test_struct_subclass
+      so = StructSubclass.new('foo', [1,2,3])
+      assert_equal so, Psych.load(Psych.dump(so))
+    end
+  end
+end
--- a/test/psych/test_set.rb
+++ b/test/psych/test_set.rb
@ -0,0 +1,49 @@
+require 'test/psych/helper'
+
+module Psych
+  class TestSet < TestCase
+    def setup
+      super
+      @set = Psych::Set.new
+      @set['foo'] = 'bar'
+      @set['bar'] = 'baz'
+    end
+
+    def test_dump
+      assert_match(/!set/, Psych.dump(@set))
+    end
+
+    def test_roundtrip
+      assert_cycle(@set)
+    end
+
+    ###
+    # FIXME: Syck should also support !!set as shorthand
+    def test_load_from_yaml
+      loaded = Psych.load(<<-eoyml)
+--- !set
+foo: bar
+bar: baz
+      eoyml
+      assert_equal(@set, loaded)
+    end
+
+    def test_loaded_class
+      assert_instance_of(Psych::Set, Psych.load(Psych.dump(@set)))
+    end
+
+    def test_set_shorthand
+      loaded = Psych.load(<<-eoyml)
+--- !!set
+foo: bar
+bar: baz
+      eoyml
+      assert_instance_of(Psych::Set, loaded)
+    end
+
+    def test_set_self_reference
+      @set['self'] = @set
+      assert_cycle(@set)
+    end
+  end
+end
--- a/test/psych/test_string.rb
+++ b/test/psych/test_string.rb
@ -0,0 +1,49 @@
+require 'test/psych/helper'
+
+module Psych
+  class TestString < TestCase
+    def test_binary_string_null
+      string = "\x00"
+      yml = Psych.dump string
+      assert_match(/binary/, yml)
+      assert_equal string, Psych.load(yml)
+    end
+
+    def test_binary_string
+      string = binary_string
+      yml = Psych.dump string
+      assert_match(/binary/, yml)
+      assert_equal string, Psych.load(yml)
+    end
+
+    def test_non_binary_string
+      string = binary_string(0.29)
+      yml = Psych.dump string
+      refute_match(/binary/, yml)
+      assert_equal string, Psych.load(yml)
+    end
+
+    def test_string_with_ivars
+      food = "is delicious"
+      ivar = "on rock and roll"
+      food.instance_variable_set(:@we_built_this_city, ivar)
+
+      str = Psych.load Psych.dump food
+      assert_equal ivar, food.instance_variable_get(:@we_built_this_city)
+    end
+
+    def test_binary
+      string = [0, 123,22, 44, 9, 32, 34, 39].pack('C*')
+      assert_cycle string
+    end
+
+    def binary_string percentage = 0.31, length = 100
+      string = ''
+      (percentage * length).to_i.times do |i|
+        string << "\b"
+      end
+      string << 'a' * (length - string.length)
+      string
+    end
+  end
+end
--- a/test/psych/test_struct.rb
+++ b/test/psych/test_struct.rb
@ -0,0 +1,51 @@
+require 'test/psych/helper'
+
+class PsychStructWithIvar < Struct.new(:foo)
+  attr_reader :bar
+  def initialize *args
+    super
+    @bar = 'hello'
+  end
+end
+
+module Psych
+  class TestStruct < TestCase
+    class StructSubclass < Struct.new(:foo)
+      def initialize foo, bar
+        super(foo)
+        @bar = bar
+      end
+    end
+
+    def test_self_referential_struct
+      ss = StructSubclass.new(nil, 'foo')
+      ss.foo = ss
+
+      loaded = Psych.load(Psych.dump(ss))
+      assert_instance_of(StructSubclass, loaded.foo)
+
+      # FIXME: This seems to cause an infinite loop.  wtf.  Must report a bug
+      # in ruby.
+      # assert_equal(ss, loaded)
+    end
+
+    def test_roundtrip
+      thing = PsychStructWithIvar.new('bar')
+      struct = Psych.load(Psych.dump(thing))
+
+      assert_equal 'hello', struct.bar
+      assert_equal 'bar', struct.foo
+    end
+
+    def test_load
+      obj = Psych.load(<<-eoyml)
+--- !ruby/struct:PsychStructWithIvar 
+:foo: bar
+:@bar: hello
+      eoyml
+
+      assert_equal 'hello', obj.bar
+      assert_equal 'bar', obj.foo
+    end
+  end
+end
--- a/test/psych/test_symbol.rb
+++ b/test/psych/test_symbol.rb
@ -0,0 +1,17 @@
+require 'test/psych/helper'
+
+module Psych
+  class TestSymbol < TestCase
+    def test_cycle
+      assert_cycle :a
+    end
+
+    def test_stringy
+      assert_cycle :"1"
+    end
+
+    def test_load_quoted
+      assert_equal :"1", Psych.load("--- :'1'\n")
+    end
+  end
+end
--- a/test/psych/test_to_yaml_properties.rb
+++ b/test/psych/test_to_yaml_properties.rb
@ -0,0 +1,63 @@
+require 'test/psych/helper'
+
+module Psych
+  class TestToYamlProperties < MiniTest::Unit::TestCase
+    class Foo
+      attr_accessor :a, :b, :c
+      def initialize
+        @a = 1
+        @b = 2
+        @c = 3
+      end
+
+      def to_yaml_properties
+        [:@a, :@b]
+      end
+    end
+
+    def test_object_dump_yaml_properties
+      foo = Psych.load(Psych.dump(Foo.new))
+      assert_equal 1, foo.a
+      assert_equal 2, foo.b
+      assert_nil foo.c
+    end
+
+    class Bar < Struct.new(:foo, :bar)
+      attr_reader :baz
+      def initialize *args
+        super
+        @baz = 'hello'
+      end
+
+      def to_yaml_properties
+        []
+      end
+    end
+
+    def test_struct_dump_yaml_properties
+      bar = Psych.load(Psych.dump(Bar.new('a', 'b')))
+      assert_equal 'a', bar.foo
+      assert_equal 'b', bar.bar
+      assert_nil bar.baz
+    end
+
+    def test_string_dump
+      string = "okonomiyaki"
+      class << string
+        def to_yaml_properties
+          [:@tastes]
+        end
+      end
+
+      string.instance_variable_set(:@tastes, 'delicious')
+      v = Psych.load Psych.dump string
+      assert_equal 'delicious', v.instance_variable_get(:@tastes)
+    end
+
+    def test_string_load_syck
+      str = Psych.load("--- !str \nstr: okonomiyaki\n:@tastes: delicious\n")
+      assert_equal 'okonomiyaki', str
+      assert_equal 'delicious', str.instance_variable_get(:@tastes)
+    end
+  end
+end
--- a/test/psych/test_tree_builder.rb
+++ b/test/psych/test_tree_builder.rb
@ -0,0 +1,79 @@
+require 'test/psych/helper'
+
+module Psych
+  class TestTreeBuilder < TestCase
+    def setup
+      super
+      @parser = Psych::Parser.new TreeBuilder.new
+      @parser.parse(<<-eoyml)
+%YAML 1.1
+---
+- foo
+- {
+  bar : &A !!str baz,
+  boo : *A
+}
+- *A
+      eoyml
+      @tree = @parser.handler.root
+    end
+
+    def test_stream
+      assert_instance_of Nodes::Stream, @tree
+    end
+
+    def test_documents
+      assert_equal 1, @tree.children.length
+      assert_instance_of Nodes::Document, @tree.children.first
+      doc = @tree.children.first
+
+      assert_equal [1,1], doc.version
+      assert_equal [], doc.tag_directives
+      assert_equal false, doc.implicit
+    end
+
+    def test_sequence
+      doc = @tree.children.first
+      assert_equal 1, doc.children.length
+
+      seq = doc.children.first
+      assert_instance_of Nodes::Sequence, seq
+      assert_nil seq.anchor
+      assert_nil seq.tag
+      assert_equal true, seq.implicit
+      assert_equal Nodes::Sequence::BLOCK, seq.style
+    end
+
+    def test_scalar
+      doc = @tree.children.first
+      seq = doc.children.first
+
+      assert_equal 3, seq.children.length
+      scalar = seq.children.first
+      assert_instance_of Nodes::Scalar, scalar
+      assert_equal 'foo', scalar.value
+      assert_nil scalar.anchor
+      assert_nil scalar.tag
+      assert_equal true, scalar.plain
+      assert_equal false, scalar.quoted
+      assert_equal Nodes::Scalar::PLAIN, scalar.style
+    end
+
+    def test_mapping
+      doc = @tree.children.first
+      seq = doc.children.first
+      map = seq.children[1]
+
+      assert_instance_of Nodes::Mapping, map
+    end
+
+    def test_alias
+      doc = @tree.children.first
+      seq = doc.children.first
+      assert_equal 3, seq.children.length
+      al  = seq.children[2]
+      assert_instance_of Nodes::Alias, al
+      assert_equal 'A', al.anchor
+    end
+  end
+end
--- a/test/psych/test_yaml.rb
+++ b/test/psych/test_yaml.rb
--- a/test/psych/visitors/test_emitter.rb
+++ b/test/psych/visitors/test_emitter.rb
@ -0,0 +1,124 @@
+require 'test/psych/helper'
+
+module Psych
+  module Visitors
+    class TestEmitter < TestCase
+      def setup
+        super
+        @io = StringIO.new
+        @visitor = Visitors::Emitter.new @io
+      end
+
+      def test_stream
+        s = Nodes::Stream.new
+        @visitor.accept s
+        assert_equal '', @io.string
+      end
+
+      def test_document
+        s       = Nodes::Stream.new
+        doc     = Nodes::Document.new [1,1]
+        scalar  = Nodes::Scalar.new 'hello world'
+
+        doc.children << scalar
+        s.children << doc
+
+        @visitor.accept s
+
+        assert_match(/1.1/, @io.string)
+        assert_equal @io.string, s.to_yaml
+      end
+
+      def test_document_implicit_end
+        s       = Nodes::Stream.new
+        doc     = Nodes::Document.new
+        mapping = Nodes::Mapping.new
+        mapping.children << Nodes::Scalar.new('key')
+        mapping.children << Nodes::Scalar.new('value')
+        doc.children << mapping
+        s.children << doc
+
+        @visitor.accept s
+
+        assert_match(/key: value/, @io.string)
+        assert_equal @io.string, s.to_yaml
+        assert(/\.\.\./ !~ s.to_yaml)
+      end
+
+      def test_scalar
+        s       = Nodes::Stream.new
+        doc     = Nodes::Document.new
+        scalar  = Nodes::Scalar.new 'hello world'
+
+        doc.children << scalar
+        s.children << doc
+
+        @visitor.accept s
+
+        assert_match(/hello/, @io.string)
+        assert_equal @io.string, s.to_yaml
+      end
+
+      def test_scalar_with_tag
+        s       = Nodes::Stream.new
+        doc     = Nodes::Document.new
+        scalar  = Nodes::Scalar.new 'hello world', nil, '!str', false, false, 5
+
+        doc.children << scalar
+        s.children << doc
+
+        @visitor.accept s
+
+        assert_match(/str/, @io.string)
+        assert_match(/hello/, @io.string)
+        assert_equal @io.string, s.to_yaml
+      end
+
+      def test_sequence
+        s       = Nodes::Stream.new
+        doc     = Nodes::Document.new
+        scalar  = Nodes::Scalar.new 'hello world'
+        seq     = Nodes::Sequence.new
+
+        seq.children << scalar
+        doc.children << seq
+        s.children << doc
+
+        @visitor.accept s
+
+        assert_match(/- hello/, @io.string)
+        assert_equal @io.string, s.to_yaml
+      end
+
+      def test_mapping
+        s       = Nodes::Stream.new
+        doc     = Nodes::Document.new
+        mapping = Nodes::Mapping.new
+        mapping.children << Nodes::Scalar.new('key')
+        mapping.children << Nodes::Scalar.new('value')
+        doc.children << mapping
+        s.children << doc
+
+        @visitor.accept s
+
+        assert_match(/key: value/, @io.string)
+        assert_equal @io.string, s.to_yaml
+      end
+
+      def test_alias
+        s       = Nodes::Stream.new
+        doc     = Nodes::Document.new
+        mapping = Nodes::Mapping.new
+        mapping.children << Nodes::Scalar.new('key', 'A')
+        mapping.children << Nodes::Alias.new('A')
+        doc.children << mapping
+        s.children << doc
+
+        @visitor.accept s
+
+        assert_match(/&A key: \*A/, @io.string)
+        assert_equal @io.string, s.to_yaml
+      end
+    end
+  end
+end
--- a/test/psych/visitors/test_to_ruby.rb
+++ b/test/psych/visitors/test_to_ruby.rb
@ -0,0 +1,323 @@
+require 'test/psych/helper'
+
+module Psych
+  module Visitors
+    class TestToRuby < TestCase
+      def setup
+        super
+        @visitor = ToRuby.new
+      end
+
+      def test_object
+        mapping = Nodes::Mapping.new nil, "!ruby/object"
+        mapping.children << Nodes::Scalar.new('foo')
+        mapping.children << Nodes::Scalar.new('bar')
+
+        o = mapping.to_ruby
+        assert_equal 'bar', o.instance_variable_get(:@foo)
+      end
+
+      def test_awesome
+        Psych.load('1900-01-01T00:00:00+00:00')
+      end
+
+      def test_legacy_struct
+        foo = Struct.new('AWESOME', :bar)
+        assert_equal foo.new('baz'), Psych.load(<<-eoyml)
+!ruby/struct:AWESOME
+  bar: baz
+        eoyml
+      end
+
+      def test_binary
+        gif = "GIF89a\f\x00\f\x00\x84\x00\x00\xFF\xFF\xF7\xF5\xF5\xEE\xE9\xE9\xE5fff\x00\x00\x00\xE7\xE7\xE7^^^\xF3\xF3\xED\x8E\x8E\x8E\xE0\xE0\xE0\x9F\x9F\x9F\x93\x93\x93\xA7\xA7\xA7\x9E\x9E\x9Eiiiccc\xA3\xA3\xA3\x84\x84\x84\xFF\xFE\xF9\xFF\xFE\xF9\xFF\xFE\xF9\xFF\xFE\xF9\xFF\xFE\xF9\xFF\xFE\xF9\xFF\xFE\xF9\xFF\xFE\xF9\xFF\xFE\xF9\xFF\xFE\xF9\xFF\xFE\xF9\xFF\xFE\xF9\xFF\xFE\xF9\xFF\xFE\xF9!\xFE\x0EMade with GIMP\x00,\x00\x00\x00\x00\f\x00\f\x00\x00\x05,  \x8E\x810\x9E\xE3@\x14\xE8i\x10\xC4\xD1\x8A\b\x1C\xCF\x80M$z\xEF\xFF0\x85p\xB8\xB01f\r\e\xCE\x01\xC3\x01\x1E\x10' \x82\n\x01\x00;"
+
+        hash = Psych.load(<<-'eoyaml')
+canonical: !!binary "\
+ R0lGODlhDAAMAIQAAP//9/X17unp5WZmZgAAAOfn515eXvPz7Y6OjuDg4J+fn5\
+ OTk6enp56enmlpaWNjY6Ojo4SEhP/++f/++f/++f/++f/++f/++f/++f/++f/+\
+ +f/++f/++f/++f/++f/++SH+Dk1hZGUgd2l0aCBHSU1QACwAAAAADAAMAAAFLC\
+ AgjoEwnuNAFOhpEMTRiggcz4BNJHrv/zCFcLiwMWYNG84BwwEeECcgggoBADs="
+generic: !binary |
+ R0lGODlhDAAMAIQAAP//9/X17unp5WZmZgAAAOfn515eXvPz7Y6OjuDg4J+fn5
+ OTk6enp56enmlpaWNjY6Ojo4SEhP/++f/++f/++f/++f/++f/++f/++f/++f/+
+ +f/++f/++f/++f/++f/++SH+Dk1hZGUgd2l0aCBHSU1QACwAAAAADAAMAAAFLC
+ AgjoEwnuNAFOhpEMTRiggcz4BNJHrv/zCFcLiwMWYNG84BwwEeECcgggoBADs=
+description:
+ The binary value above is a tiny arrow encoded as a gif image.
+        eoyaml
+        assert_equal gif, hash['canonical']
+        assert_equal gif, hash['generic']
+      end
+
+      A = Struct.new(:foo)
+
+      def test_struct
+        s = A.new('bar')
+
+        mapping = Nodes::Mapping.new nil, "!ruby/struct:#{s.class}"
+        mapping.children << Nodes::Scalar.new('foo')
+        mapping.children << Nodes::Scalar.new('bar')
+
+        ruby = mapping.to_ruby
+
+        assert_equal s.class, ruby.class
+        assert_equal s.foo, ruby.foo
+        assert_equal s, ruby
+      end
+
+      def test_anon_struct_legacy
+        s = Struct.new(:foo).new('bar')
+
+        mapping = Nodes::Mapping.new nil, '!ruby/struct:'
+        mapping.children << Nodes::Scalar.new('foo')
+        mapping.children << Nodes::Scalar.new('bar')
+
+        assert_equal s.foo, mapping.to_ruby.foo
+      end
+
+      def test_anon_struct
+        s = Struct.new(:foo).new('bar')
+
+        mapping = Nodes::Mapping.new nil, '!ruby/struct'
+        mapping.children << Nodes::Scalar.new('foo')
+        mapping.children << Nodes::Scalar.new('bar')
+
+        assert_equal s.foo, mapping.to_ruby.foo
+      end
+
+      def test_exception
+        exc = Exception.new 'hello'
+
+        mapping = Nodes::Mapping.new nil, '!ruby/exception'
+        mapping.children << Nodes::Scalar.new('message')
+        mapping.children << Nodes::Scalar.new('hello')
+
+        ruby = mapping.to_ruby
+
+        assert_equal exc.class, ruby.class
+        assert_equal exc.message, ruby.message
+      end
+
+      def test_regexp
+        node = Nodes::Scalar.new('/foo/', nil, '!ruby/regexp')
+        assert_equal(/foo/, node.to_ruby)
+
+        node = Nodes::Scalar.new('/foo/m', nil, '!ruby/regexp')
+        assert_equal(/foo/m, node.to_ruby)
+
+        node = Nodes::Scalar.new('/foo/ix', nil, '!ruby/regexp')
+        assert_equal(/foo/ix, node.to_ruby)
+      end
+
+      def test_time
+        now = Time.now
+        formatted = now.strftime("%Y-%m-%d %H:%M:%S") +
+          ".%06d %+.2d:00" % [now.usec, now.gmt_offset / 3600]
+
+        assert_equal now, Nodes::Scalar.new(formatted).to_ruby
+      end
+
+      def test_time_utc
+        now = Time.now.utc
+        formatted = now.strftime("%Y-%m-%d %H:%M:%S") +
+          ".%06dZ" % [now.usec]
+
+        assert_equal now, Nodes::Scalar.new(formatted).to_ruby
+      end
+
+      def test_time_utc_no_z
+        now = Time.now.utc
+        formatted = now.strftime("%Y-%m-%d %H:%M:%S") +
+          ".%06d" % [now.usec]
+
+        assert_equal now, Nodes::Scalar.new(formatted).to_ruby
+      end
+
+      def test_date
+        d = '1980-12-16'
+        actual = Date.strptime(d, '%Y-%m-%d')
+
+        date = Nodes::Scalar.new(d, nil, 'tag:yaml.org,2002:timestamp', false)
+
+        assert_equal actual, date.to_ruby
+      end
+
+      def test_rational
+        mapping = Nodes::Mapping.new nil, '!ruby/object:Rational'
+        mapping.children << Nodes::Scalar.new('denominator')
+        mapping.children << Nodes::Scalar.new('2')
+        mapping.children << Nodes::Scalar.new('numerator')
+        mapping.children << Nodes::Scalar.new('1')
+
+        assert_equal Rational(1,2), mapping.to_ruby
+      end
+
+      def test_complex
+        mapping = Nodes::Mapping.new nil, '!ruby/object:Complex'
+        mapping.children << Nodes::Scalar.new('image')
+        mapping.children << Nodes::Scalar.new('2')
+        mapping.children << Nodes::Scalar.new('real')
+        mapping.children << Nodes::Scalar.new('1')
+
+        assert_equal Complex(1,2), mapping.to_ruby
+      end
+
+      if RUBY_VERSION >= '1.9'
+        def test_complex_string
+          node = Nodes::Scalar.new '3+4i', nil, "!ruby/object:Complex"
+          assert_equal Complex(3, 4), node.to_ruby
+        end
+
+        def test_rational_string
+          node = Nodes::Scalar.new '1/2', nil, "!ruby/object:Rational"
+          assert_equal Rational(1, 2), node.to_ruby
+        end
+      end
+
+      def test_range_string
+        node = Nodes::Scalar.new '1..2', nil, "!ruby/range"
+        assert_equal 1..2, node.to_ruby
+      end
+
+      def test_range_string_triple
+        node = Nodes::Scalar.new '1...3', nil, "!ruby/range"
+        assert_equal 1...3, node.to_ruby
+      end
+
+      def test_integer
+        i = Nodes::Scalar.new('1', nil, 'tag:yaml.org,2002:int')
+        assert_equal 1, i.to_ruby
+
+        assert_equal 1, Nodes::Scalar.new('1').to_ruby
+
+        i = Nodes::Scalar.new('-1', nil, 'tag:yaml.org,2002:int')
+        assert_equal(-1, i.to_ruby)
+
+        assert_equal(-1, Nodes::Scalar.new('-1').to_ruby)
+        assert_equal 1, Nodes::Scalar.new('+1').to_ruby
+      end
+
+      def test_int_ignore
+        ['1,000', '1_000'].each do |num|
+          i = Nodes::Scalar.new(num, nil, 'tag:yaml.org,2002:int')
+          assert_equal 1000, i.to_ruby
+
+          assert_equal 1000, Nodes::Scalar.new(num).to_ruby
+        end
+      end
+
+      def test_float_ignore
+        ['1,000.3', '1_000.3'].each do |num|
+          i = Nodes::Scalar.new(num, nil, 'tag:yaml.org,2002:float')
+          assert_equal 1000.3, i.to_ruby
+
+          i = Nodes::Scalar.new(num, nil, '!float')
+          assert_equal 1000.3, i.to_ruby
+
+          assert_equal 1000.3, Nodes::Scalar.new(num).to_ruby
+        end
+      end
+
+      # http://yaml.org/type/bool.html
+      def test_boolean_true
+        %w{ yes Yes YES true True TRUE on On ON }.each do |t|
+          i = Nodes::Scalar.new(t, nil, 'tag:yaml.org,2002:bool')
+          assert_equal true, i.to_ruby
+          assert_equal true, Nodes::Scalar.new(t).to_ruby
+        end
+      end
+
+      # http://yaml.org/type/bool.html
+      def test_boolean_false
+        %w{ no No NO false False FALSE off Off OFF }.each do |t|
+          i = Nodes::Scalar.new(t, nil, 'tag:yaml.org,2002:bool')
+          assert_equal false, i.to_ruby
+          assert_equal false, Nodes::Scalar.new(t).to_ruby
+        end
+      end
+
+      def test_float
+        i = Nodes::Scalar.new('12', nil, 'tag:yaml.org,2002:float')
+        assert_equal 12.0, i.to_ruby
+
+        i = Nodes::Scalar.new('1.2', nil, 'tag:yaml.org,2002:float')
+        assert_equal 1.2, i.to_ruby
+
+        i = Nodes::Scalar.new('1.2')
+        assert_equal 1.2, i.to_ruby
+
+        assert_equal 1, Nodes::Scalar.new('.Inf').to_ruby.infinite?
+        assert_equal 1, Nodes::Scalar.new('.inf').to_ruby.infinite?
+        assert_equal 1, Nodes::Scalar.new('.Inf', nil, 'tag:yaml.org,2002:float').to_ruby.infinite?
+
+        assert_equal(-1, Nodes::Scalar.new('-.inf').to_ruby.infinite?)
+        assert_equal(-1, Nodes::Scalar.new('-.Inf').to_ruby.infinite?)
+        assert_equal(-1, Nodes::Scalar.new('-.Inf', nil, 'tag:yaml.org,2002:float').to_ruby.infinite?)
+
+        assert Nodes::Scalar.new('.NaN').to_ruby.nan?
+        assert Nodes::Scalar.new('.NaN', nil, 'tag:yaml.org,2002:float').to_ruby.nan?
+      end
+
+      def test_exp_float
+        exp = 1.2e+30
+
+        i = Nodes::Scalar.new(exp.to_s, nil, 'tag:yaml.org,2002:float')
+        assert_equal exp, i.to_ruby
+
+        assert_equal exp, Nodes::Scalar.new(exp.to_s).to_ruby
+      end
+
+      def test_scalar
+        scalar = Nodes::Scalar.new('foo')
+        assert_equal 'foo', @visitor.accept(scalar)
+        assert_equal 'foo', scalar.to_ruby
+      end
+
+      def test_sequence
+        seq = Nodes::Sequence.new
+        seq.children << Nodes::Scalar.new('foo')
+        seq.children << Nodes::Scalar.new('bar')
+
+        assert_equal %w{ foo bar }, seq.to_ruby
+      end
+
+      def test_mapping
+        mapping = Nodes::Mapping.new
+        mapping.children << Nodes::Scalar.new('foo')
+        mapping.children << Nodes::Scalar.new('bar')
+        assert_equal({'foo' => 'bar'}, mapping.to_ruby)
+      end
+
+      def test_document
+        doc = Nodes::Document.new
+        doc.children << Nodes::Scalar.new('foo')
+        assert_equal 'foo', doc.to_ruby
+      end
+
+      def test_stream
+        a = Nodes::Document.new
+        a.children << Nodes::Scalar.new('foo')
+
+        b = Nodes::Document.new
+        b.children << Nodes::Scalar.new('bar')
+
+        stream = Nodes::Stream.new
+        stream.children << a
+        stream.children << b
+
+        assert_equal %w{ foo bar }, stream.to_ruby
+      end
+
+      def test_alias
+        seq = Nodes::Sequence.new
+        seq.children << Nodes::Scalar.new('foo', 'A')
+        seq.children << Nodes::Alias.new('A')
+
+        list = seq.to_ruby
+        assert_equal %w{ foo foo }, list
+        assert_equal list[0].object_id, list[1].object_id
+      end
+    end
+  end
+end
--- a/test/psych/visitors/test_yaml_tree.rb
+++ b/test/psych/visitors/test_yaml_tree.rb
@ -0,0 +1,140 @@
+require 'test/psych/helper'
+
+module Psych
+  module Visitors
+    class TestYAMLTree < TestCase
+      def setup
+        super
+        @v = Visitors::YAMLTree.new
+      end
+
+      def test_object_has_no_class
+        yaml = Psych.dump(Object.new)
+        assert(Psych.dump(Object.new) !~ /Object/, yaml)
+      end
+
+      def test_struct_const
+        foo = Struct.new("Foo", :bar)
+        assert_cycle foo.new('bar')
+      end
+
+      A = Struct.new(:foo)
+
+      def test_struct
+        assert_cycle A.new('bar')
+      end
+
+      def test_struct_anon
+        s = Struct.new(:foo).new('bar')
+        obj =  Psych.load(Psych.dump(s))
+        assert_equal s.foo, obj.foo
+      end
+
+      def test_exception
+        ex = Exception.new 'foo'
+        loaded = Psych.load(Psych.dump(ex))
+
+        assert_equal ex.message, loaded.message
+        assert_equal ex.class, loaded.class
+      end
+
+      def test_regexp
+        assert_cycle(/foo/)
+        assert_cycle(/foo/i)
+        assert_cycle(/foo/mx)
+      end
+
+      def test_time
+        assert_cycle Time.now
+      end
+
+      def test_date
+        date = Date.strptime('2002-12-14', '%Y-%m-%d')
+        assert_cycle date
+      end
+
+      def test_rational
+        assert_cycle Rational(1,2)
+      end
+
+      def test_complex
+        assert_cycle Complex(1,2)
+      end
+
+      def test_scalar
+        assert_cycle 'foo'
+        assert_cycle ':foo'
+        assert_cycle ''
+        assert_cycle ':'
+      end
+
+      def test_boolean
+        assert_cycle true
+        assert_cycle 'true'
+        assert_cycle false
+        assert_cycle 'false'
+      end
+
+      def test_range_inclusive
+        assert_cycle 1..2
+      end
+
+      def test_range_exclusive
+        assert_cycle 1...2
+      end
+
+      def test_anon_class
+        assert_raises(TypeError) do
+          @v.accept Class.new
+        end
+
+        assert_raises(TypeError) do
+          Psych.dump(Class.new)
+        end
+      end
+
+      def test_hash
+        assert_cycle('a' => 'b')
+      end
+
+      def test_list
+        assert_cycle(%w{ a b })
+        assert_cycle([1, 2.2])
+      end
+
+      def test_symbol
+        assert_cycle :foo
+      end
+
+      def test_int
+        assert_cycle 1
+        assert_cycle(-1)
+        assert_cycle '1'
+        assert_cycle '-1'
+      end
+
+      def test_float
+        assert_cycle 1.2
+        assert_cycle '1.2'
+
+        assert Psych.load(Psych.dump(0.0 / 0.0)).nan?
+        assert_equal 1, Psych.load(Psych.dump(1 / 0.0)).infinite?
+        assert_equal(-1, Psych.load(Psych.dump(-1 / 0.0)).infinite?)
+      end
+
+      # http://yaml.org/type/null.html
+      def test_nil
+        assert_cycle nil
+        assert_equal nil, Psych.load('null')
+        assert_equal nil, Psych.load('Null')
+        assert_equal nil, Psych.load('NULL')
+        assert_equal nil, Psych.load('~')
+        assert_equal({'foo' => nil}, Psych.load('foo: '))
+
+        assert_cycle 'null'
+        assert_cycle 'nUll'
+        assert_cycle '~'
+      end
+    end
+  end
+end