Add ext/enumerator, a helper module for the Enumerable interface.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@4753 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Tue Oct 14 02:05:23 2003  Akinori MUSHA  <knu@iDaemons.org>
+
+	* ext/Setup*, ext/enumerator/*: Add ext/enumerator, a helper
+	  module for the Enumerable interface.
+
 Mon Oct 13 23:55:59 2003  WATANABE Hirofumi  <eban@ruby-lang.org>
 
 	* test/ruby/envutil.rb: use Config::CONFIG["ruby_install_name"],

doc/NEWS

@@ -649,7 +649,7 @@
   Extended to take an address and a port number for the local side in
   optional 3rd and 4th arguments.
 
-= new bundled library
+= newly bundled library
 
 : ext/bigdecimal
 
@@ -659,6 +659,10 @@
 
   an interface to the dynamic linker.
 
+: ext/enumerator
+
+  a helper module for the Enumerable interface.
+
 : ext/io/wait
 
   IO wait methods.

ext/Setup

@@ -10,6 +10,7 @@
 #digest/sha1
 #digest/sha2
 #dl
+#enumerator
 #etc
 #fcntl
 #gdbm

ext/Setup.atheos

@@ -10,6 +10,7 @@ digest/rmd160
 digest/sha1
 digest/sha2
 dl
+enumerator
 etc
 fcntl
 gdbm

ext/Setup.dj

@@ -11,6 +11,7 @@ digest/sha1
 digest/sha2
 #dl
 #etc
+enumerator
 fcntl
 gdbm
 #iconv

ext/Setup.emx

@@ -10,6 +10,7 @@ digest/rmd160
 digest/sha1
 digest/sha2
 #dl
+enumerator
 etc
 fcntl
 #gdbm

ext/Setup.nt

@@ -10,6 +10,7 @@ digest/rmd160
 digest/sha1
 digest/sha2
 dl
+enumerator
 etc
 fcntl
 #gdbm

ext/Setup.x68

@@ -11,6 +11,7 @@ digest/sha1
 digest/sha2
 #dl
 #etc
+enumerator
 fcntl
 #gdbm
 #iconv

ext/enumerator/.cvsignore

@@ -0,0 +1,2 @@
+Makefile
+mkmf.log

ext/enumerator/MANIFEST

@@ -0,0 +1,3 @@
+MANIFEST
+enumerator.c
+enumerator.txt

ext/enumerator/enumerator.c

@@ -0,0 +1,200 @@
+/************************************************
+
+  enumerator.c - provides Enumerator class
+
+  $Author$
+
+  Copyright (C) 2001-2003 Akinori MUSHA
+
+  $Idaemons: /home/cvs/rb/enumerator/enumerator.c,v 1.1.1.1 2001/07/15 10:12:48 knu Exp $
+  $RoughId: enumerator.c,v 1.6 2003/07/27 11:03:24 nobu Exp $
+  $Id$
+
+************************************************/
+
+#include "ruby.h"
+#include "node.h"
+
+static VALUE rb_cEnumerator;
+static ID sym_each, sym_each_with_index, sym_each_slice, sym_each_cons;
+static ID id_new, id_enum_obj, id_enum_method, id_enum_args;
+
+static VALUE
+obj_enum_for(obj, enum_args)
+    VALUE obj, enum_args;
+{
+    rb_ary_unshift(enum_args, obj);
+
+    return rb_apply(rb_cEnumerator, id_new, enum_args);
+}
+
+static VALUE
+enumerator_enum_with_index(obj)
+    VALUE obj;
+{
+    return rb_funcall(rb_cEnumerator, id_new, 2, obj, sym_each_with_index);
+}
+
+static VALUE
+each_slice_i(val, memo)
+    VALUE val;
+    NODE *memo;
+{
+    VALUE ary = memo->u1.value;
+    long size = memo->u3.cnt;
+
+    rb_ary_push(ary, val);
+
+    if (RARRAY(ary)->len == size) {
+	rb_yield(ary);
+	memo->u1.value = rb_ary_new2(size);
+    }
+
+    return Qnil;
+}
+
+static VALUE
+enum_each_slice(obj, n)
+    VALUE obj, n;
+{
+    long size = NUM2LONG(n);
+    NODE *memo;
+    VALUE ary;
+
+    if (size <= 0) rb_raise(rb_eArgError, "invalid slice size");
+
+    memo = rb_node_newnode(NODE_MEMO, rb_ary_new2(size), 0, size);
+
+    rb_iterate(rb_each, obj, each_slice_i, (VALUE)memo);
+
+    ary = memo->u1.value;
+    if (RARRAY(ary)->len > 0) rb_yield(ary);
+
+    rb_gc_force_recycle((VALUE)memo);
+    return Qnil;
+}
+
+static VALUE
+enumerator_enum_slice(obj, n)
+    VALUE obj, n;
+{
+    return rb_funcall(rb_cEnumerator, id_new, 3, obj, sym_each_slice, n);
+}
+
+static VALUE
+each_cons_i(val, memo)
+    VALUE val;
+    NODE *memo;
+{
+    VALUE ary = memo->u1.value;
+    long size = memo->u3.cnt;
+    long len = RARRAY(ary)->len;
+
+    if (len == size) {
+	rb_ary_shift(ary);
+	rb_ary_push(ary, val);
+	rb_yield(ary);
+    } else {
+	rb_ary_push(ary, val);
+	if (len + 1 == size) rb_yield(ary);
+    }
+    return Qnil;
+}
+
+static VALUE
+enum_each_cons(obj, n)
+    VALUE obj, n;
+{
+    long size = NUM2LONG(n);
+    NODE *memo;
+    VALUE ary;
+
+    if (size <= 0) rb_raise(rb_eArgError, "invalid size");
+    memo = rb_node_newnode(NODE_MEMO, rb_ary_new2(size), 0, size);
+
+    rb_iterate(rb_each, obj, each_cons_i, (VALUE)memo);
+
+    rb_gc_force_recycle((VALUE)memo);
+    return Qnil;
+}
+
+static VALUE
+enumerator_enum_cons(obj, n)
+    VALUE obj, n;
+{
+    return rb_funcall(rb_cEnumerator, id_new, 3, obj, sym_each_cons, n);
+}
+
+static VALUE
+enumerator_initialize(argc, argv, obj)
+    int argc;
+    VALUE *argv;
+    VALUE obj;
+{
+    VALUE enum_obj, enum_method, enum_args;
+
+    rb_scan_args(argc, argv, "11*", &enum_obj, &enum_method, &enum_args);
+
+    if (enum_method == Qnil)
+	enum_method = sym_each;
+
+    rb_ivar_set(obj, id_enum_obj, enum_obj);
+    rb_ivar_set(obj, id_enum_method, enum_method);
+    rb_ivar_set(obj, id_enum_args, enum_args);
+
+    return Qnil;
+}
+
+static VALUE
+enumerator_iter(memo)
+    NODE *memo;
+{
+    return rb_apply(memo->u1.value, memo->u2.id, memo->u3.value);
+}
+
+static VALUE
+enumerator_each(obj)
+    VALUE obj;
+{
+    VALUE val;
+
+    obj = (VALUE)rb_node_newnode(NODE_MEMO,
+				 rb_ivar_get(obj, id_enum_obj),
+				 rb_to_id(rb_ivar_get(obj, id_enum_method)),
+				 rb_ivar_get(obj, id_enum_args));
+    val = rb_iterate(enumerator_iter, obj, rb_yield, 0);
+    rb_gc_force_recycle(obj);
+    return val;
+}
+
+void
+Init_enumerator()
+{
+    VALUE rb_mEnumerable;
+
+    rb_define_method(rb_mKernel, "enum_for", obj_enum_for, -2);
+
+    rb_mEnumerable = rb_path2class("Enumerable");
+
+    rb_define_method(rb_mEnumerable, "enum_with_index", enumerator_enum_with_index, 0);
+    rb_define_method(rb_mEnumerable, "each_slice", enum_each_slice, 1);
+    rb_define_method(rb_mEnumerable, "enum_slice", enumerator_enum_slice, 1);
+    rb_define_method(rb_mEnumerable, "each_cons", enum_each_cons, 1);
+    rb_define_method(rb_mEnumerable, "enum_cons", enumerator_enum_cons, 1);
+
+    rb_cEnumerator = rb_define_class_under(rb_mEnumerable, "Enumerator", rb_cObject);
+    rb_include_module(rb_cEnumerator, rb_mEnumerable);
+
+    rb_define_method(rb_cEnumerator, "initialize", enumerator_initialize, -1);
+    rb_define_method(rb_cEnumerator, "each", enumerator_each, 0);
+
+    sym_each		= ID2SYM(rb_intern("each"));
+    sym_each_with_index	= ID2SYM(rb_intern("each_with_index"));
+    sym_each_slice	= ID2SYM(rb_intern("each_slice"));
+    sym_each_cons	= ID2SYM(rb_intern("each_cons"));
+
+    id_new		= rb_intern("new");
+    id_enum_obj		= rb_intern("enum_obj");
+    id_enum_method	= rb_intern("enum_method");
+    id_enum_args	= rb_intern("enum_args");
+}

ext/enumerator/enumerator.txt

@@ -0,0 +1,97 @@
+.\" enumerator.txt -  -*- Indented-Text -*-
+$Idaemons: /home/cvs/rb/enumerator/enumerator.txt,v 1.2 2001/07/15 10:19:24 knu Exp $
+$RoughId: enumerator.txt,v 1.5 2003/02/20 12:24:51 knu Exp $
+$Id$
+
+** Enumerable::Enumerator(Class)
+
+A class which provides a method `each' to be used as an Enumerable
+object.
+
+Superclass: Object
+
+Mix-ins: Enumerable
+
+require 'enumerator'
+
+Class Methods:
+
+    new(obj, method = :each, *args)
+
+	Creates a new Enumerable::Enumerator object, which is to be
+	used as an Enumerable object using the given object's given
+	method with the given arguments.
+
+	e.g.:
+	    str = "xyz"
+
+	    enum = Enumerable::Enumerator.new(str, :each_byte)
+	    a = enum.map {|b| '%02x' % b } #=> ["78", "79", "7a"]
+
+Methods:
+
+    each {...}
+
+	Iterates the given block using the object and the method
+	specified in the first place.
+
+
+Requiring this module also adds some methods to the Object class:
+
+    enum_for(method = :each, *args)
+
+	Returns Enumerable::Enumerator.new(self, method, *args).
+
+	e.g.:
+	    str = "xyz"
+
+	    enum = str.enum_for(:each_byte)
+	    a = enum.map {|b| '%02x' % b } #=> ["78", "79", "7a"]
+
+And the Enumerable module.
+
+    each_slice(n) {...}
+
+	Iterates the given block for each slice of <n> elements.
+
+	e.g.:
+	    (1..10).each_slice(3) {|a| p a}
+	    # outputs below
+	    [1, 2, 3]
+	    [4, 5, 6]
+	    [7, 8, 9]
+	    [10]
+
+    enum_slice(n)
+
+	Returns Enumerable::Enumerator.new(self, :each_slice, n).
+
+    each_cons(n) {...}
+
+	Iterates the given block for each array of consecutive <n>
+	elements.
+
+	e.g.:
+	    (1..10).each_cons(3) {|a| p a}
+	    # outputs below
+	    [1, 2, 3]
+	    [2, 3, 4]
+	    [3, 4, 5]
+	    [4, 5, 6]
+	    [5, 6, 7]
+	    [6, 7, 8]
+	    [7, 8, 9]
+	    [8, 9, 10]
+
+    enum_cons(n)
+
+	Returns Enumerable::Enumerator.new(self, :each_cons, n).
+
+    enum_with_index
+
+	Returns Enumerable::Enumerator.new(self, :each_with_index).
+
+-------------------------------------------------------
+Local variables:
+fill-column: 70
+end: