* array.c (rb_ary_shuffle_bang): new method.

* array.c (rb_ary_shuffle): ditto.

* random.c (genrand_real): ditto.

* random.c (genrand_int32): export the function.

* random.c (Init_Random): initialize random seed at the
  beginning.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@10808 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,16 @@
+Thu Aug 31 17:16:19 2006  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* array.c (rb_ary_shuffle_bang): new method.
+
+	* array.c (rb_ary_shuffle): ditto.
+
+	* random.c (genrand_real): ditto.
+
+	* random.c (genrand_int32): export the function.
+
+	* random.c (Init_Random): initialize random seed at the
+	  beginning.
+
 Thu Aug 31 13:12:06 2006  why the lucky stiff  <why@ruby-lang.org>
 
 	* eval.c (ruby_init): rename top_cref to ruby_top_cref and export,

array.c

@@ -1222,11 +1222,11 @@ rb_ary_join(VALUE ary, VALUE sep)
 
     for (i=0; i<RARRAY(ary)->len; i++) {
 	tmp = rb_check_string_type(RARRAY(ary)->ptr[i]);
-	len += NIL_P(tmp) ? 10 : RSTRING(tmp)->len;
+	len += NIL_P(tmp) ? 10 : RSTRING_LEN(tmp);
     }
     if (!NIL_P(sep)) {
 	StringValue(sep);
-	len += RSTRING(sep)->len * (RARRAY(ary)->len - 1);
+	len += RSTRING_LEN(sep) * (RARRAY(ary)->len - 1);
     }
     result = rb_str_buf_new(len);
     for (i=0; i<RARRAY(ary)->len; i++) {
@@ -2799,6 +2799,47 @@ rb_ary_flatten(int argc, VALUE *argv, VALUE ary)
     return ary;
 }
 
+/*
+ *  call-seq:
+ *     array.shuffle!        -> array or
+ *  
+ *  Shuffles elements in _self_ in place.
+ */
+
+
+static VALUE
+rb_ary_shuffle_bang(VALUE ary)
+{
+    long i = RARRAY(ary)->len;
+
+    while (i) {
+	long j = genrand_real()*i;
+	VALUE tmp = RARRAY(ary)->ptr[--i];
+	RARRAY(ary)->ptr[i] = RARRAY(ary)->ptr[j];
+	RARRAY(ary)->ptr[j] = tmp;
+    }
+    return ary;
+}
+
+
+/*
+ *  call-seq:
+ *     array.shuffle -> an_array
+ *  
+ *  Returns a new array that with elements of this array shuffled.
+ *     
+ *     s = [ 1, 2, 3 ]           #=> [1, 2, 3]
+ *     a.shuffle                 #=> [1, 2, 3]
+ */
+
+static VALUE
+rb_ary_shuffle(VALUE ary)
+{
+    ary = rb_ary_dup(ary);
+    rb_ary_shuffle_bang(ary);
+    return ary;
+}
+
 
 /* Arrays are ordered, integer-indexed collections of any object. 
  * Array indexing starts at 0, as in C or Java.  A negative index is 
@@ -2893,6 +2934,8 @@ Init_Array(void)
     rb_define_method(rb_cArray, "flatten", rb_ary_flatten, -1);
     rb_define_method(rb_cArray, "flatten!", rb_ary_flatten_bang, -1);
     rb_define_method(rb_cArray, "nitems", rb_ary_nitems, 0);
+    rb_define_method(rb_cArray, "shuffle!", rb_ary_shuffle_bang, 0);
+    rb_define_method(rb_cArray, "shuffle", rb_ary_shuffle, 0);
 
     id_cmp = rb_intern("<=>");
 }

intern.h

@@ -426,6 +426,9 @@ VALUE rb_detach_process(int);
 VALUE rb_range_new(VALUE, VALUE, int);
 VALUE rb_range_beg_len(VALUE, long*, long*, long, int);
 VALUE rb_length_by_each(VALUE);
+/* random.c */
+unsigned long genrand_int32(void);
+double genrand_real(void);
 /* re.c */
 int rb_memcmp(const void*,const void*,long);
 int rb_memcicmp(const void*,const void*,long);
@@ -497,6 +500,7 @@ VALUE rb_str_times(VALUE, VALUE);
 VALUE rb_str_substr(VALUE, long, long);
 void rb_str_modify(VALUE);
 VALUE rb_str_freeze(VALUE);
+void rb_str_set_len(VALUE, long);
 VALUE rb_str_resize(VALUE, long);
 VALUE rb_str_cat(VALUE, const char*, long);
 VALUE rb_str_cat2(VALUE, const char*);

random.c

@@ -145,7 +145,7 @@ next_state(void)
 }
 
 /* generates a random number on [0,0xffffffff]-interval */
-static unsigned long
+unsigned long
 genrand_int32(void)
 {
     unsigned long y;
@@ -163,7 +163,7 @@ genrand_int32(void)
 }
 
 /* generates a random number on [0,1) with 53-bit resolution*/
-static double
+double
 genrand_real(void)
 { 
     unsigned long a=genrand_int32()>>5, b=genrand_int32()>>6; 
@@ -188,7 +188,6 @@ genrand_real(void)
 #include <fcntl.h>
 #endif
 
-static int first = 1;
 static VALUE saved_seed = INT2FIX(0);
 
 static VALUE
@@ -243,7 +242,6 @@ rand_init(VALUE vseed)
             len--;
         init_by_array(buf, len);
     }
-    first = 0;
     old = saved_seed;
     saved_seed = seed;
     free(buf);
@@ -437,9 +435,6 @@ rb_f_rand(int argc, VALUE *argv, VALUE obj)
     long val, max;
 
     rb_scan_args(argc, argv, "01", &vmax);
-    if (first) {
-	rand_init(random_seed());
-    }
     switch (TYPE(vmax)) {
       case T_FLOAT:
 	if (RFLOAT(vmax)->value <= LONG_MAX && RFLOAT(vmax)->value >= LONG_MIN) {
@@ -489,6 +484,7 @@ rb_f_rand(int argc, VALUE *argv, VALUE obj)
 void
 Init_Random(void)
 {
+    rand_init(random_seed());
     rb_define_global_function("srand", rb_f_srand, -1);
     rb_define_global_function("rand", rb_f_rand, -1);
     rb_global_variable(&saved_seed);