[ruby-list:25662] Re: ブロックの返り値

なかだです。

At Sat, 28 Oct 2000 11:58:42 +0900,
[e-mail] (Yukihiro Matsumoto) wrote:
> |途中でブロックを値を返しつつ抜けたい場合は、
> |throw/catchするか、raiseするか、
> |goto(はないんでしたっけ）するか、しかないでしょうか
> 
> いまんとこないですね。

  break true みたいなのとか。

  ちょっと試しに作ってみたパッチ。


diff -up .#eval.c.1.123 eval.c
--- .#eval.c.1.123	Sat Oct 21 09:45:02 2000
+++ eval.c	Sat Oct 28 14:15:40 2000
@@ -732,7 +732,6 @@ static struct tag *prot_tag;
 
 #define PUSH_TAG(ptag) {		\
     struct tag _tag;			\
-    _tag.retval = Qnil;			\
     _tag.frame = ruby_frame;		\
     _tag.iter = ruby_iter;		\
     _tag.prev = prot_tag;		\
@@ -2084,6 +2083,7 @@ rb_eval(self, n)
 
       case NODE_WHILE:
 	PUSH_TAG(PROT_NONE);
+	result = Qnil;
 	switch (state = EXEC_TAG()) {
 	  case 0:
 	    ruby_sourceline = nd_line(node);
@@ -2104,6 +2104,7 @@ rb_eval(self, n)
 	    state = 0;
 	    goto while_next;
 	  case TAG_BREAK:
+	    result = prot_tag->retval;
 	    state = 0;
 	  default:
 	    break;
@@ -2111,10 +2112,11 @@ rb_eval(self, n)
       while_out:
 	POP_TAG();
 	if (state) JUMP_TAG(state);
-	RETURN(Qnil);
+	break;
 
       case NODE_UNTIL:
 	PUSH_TAG(PROT_NONE);
+	result = Qnil;
 	switch (state = EXEC_TAG()) {
 	  case 0:
 	    if (node->nd_state && RTEST(rb_eval(self, node->nd_cond)))
@@ -2134,6 +2136,7 @@ rb_eval(self, n)
 	    state = 0;
 	    goto until_next;
 	  case TAG_BREAK:
+	    result = prot_tag->retval;
 	    state = 0;
 	  default:
 	    break;
@@ -2141,7 +2144,7 @@ rb_eval(self, n)
       until_out:
 	POP_TAG();
 	if (state) JUMP_TAG(state);
-	RETURN(Qnil);
+	break;
 
       case NODE_BLOCK_PASS:
 	result = block_pass(self, node);
@@ -2177,7 +2180,7 @@ rb_eval(self, n)
 	    }
 	    else if (_block.tag->dst == state) {
 		state &= TAG_MASK;
-		if (state == TAG_RETURN) {
+		if (state == TAG_RETURN || state == TAG_BREAK) {
 		    result = prot_tag->retval;
 		}
 	    }
@@ -2191,7 +2194,6 @@ rb_eval(self, n)
 		goto iter_retry;
 
 	      case TAG_BREAK:
-		result = Qnil;
 		break;
 	      case TAG_RETURN:
 		return_value(result);
@@ -2203,6 +2205,12 @@ rb_eval(self, n)
 	break;
 
       case NODE_BREAK:
+	if (node->nd_stts) {
+ 	    return_value(rb_eval(self, node->nd_stts));
+ 	}
+	else {
+	    return_value(Qnil);
+	}
 	JUMP_TAG(TAG_BREAK);
 	break;
 
@@ -3242,11 +3250,19 @@ rb_f_abort()
 }
 
 void
-rb_iter_break()
+rb_break(val)
+    VALUE val;
 {
+    return_value(val);
     JUMP_TAG(TAG_BREAK);
 }
 
+void
+rb_iter_break()
+{
+    rb_break(Qnil);
+}
+
 static void rb_longjmp _((int, VALUE)) NORETURN;
 static VALUE make_backtrace _((void));
 
@@ -3704,7 +3720,6 @@ rb_iterate(it_proc, data1, bl_proc, data
 	goto iter_retry;
 
       case TAG_BREAK:
-	retval = Qnil;
 	break;
 
       case TAG_RETURN:
@@ -6103,6 +6118,7 @@ proc_call(proc, args)
     if (state) {
 	switch (state) {
 	  case TAG_BREAK:
+	    result = prot_tag->retval;
 	    break;
 	  case TAG_RETRY:
 	    rb_raise(rb_eLocalJumpError, "retry from proc-closure");
diff -up .#gc.c.1.41 gc.c
--- .#gc.c.1.41	Tue Oct 24 01:07:47 2000
+++ gc.c	Sat Oct 28 13:06:27 2000
@@ -498,6 +498,7 @@ rb_gc_mark(ptr)
 	  case NODE_DEFINED:
 	  case NODE_MATCH:
 	  case NODE_RETURN:
+	  case NODE_BREAK:
 	  case NODE_YIELD:
 	  case NODE_COLON2:
 	  case NODE_ARGS:
@@ -525,7 +526,6 @@ rb_gc_mark(ptr)
 	  case NODE_BACK_REF:
 	  case NODE_ALIAS:
 	  case NODE_VALIAS:
-	  case NODE_BREAK:
 	  case NODE_NEXT:
 	  case NODE_REDO:
 	  case NODE_RETRY:
diff -up .#node.h.1.16 node.h
--- .#node.h.1.16	Fri Sep  8 06:19:08 2000
+++ node.h	Sat Oct 28 13:05:44 2000
@@ -244,7 +244,7 @@ typedef struct RNode {
 #define NEW_UNTIL(c,b,n) rb_node_newnode(NODE_UNTIL,c,b,n)
 #define NEW_FOR(v,i,b) rb_node_newnode(NODE_FOR,v,b,i)
 #define NEW_ITER(v,i,b) rb_node_newnode(NODE_ITER,v,b,i)
-#define NEW_BREAK() rb_node_newnode(NODE_BREAK,0,0,0)
+#define NEW_BREAK(s) rb_node_newnode(NODE_BREAK,s,0,0)
 #define NEW_NEXT() rb_node_newnode(NODE_NEXT,0,0,0)
 #define NEW_REDO() rb_node_newnode(NODE_REDO,0,0,0)
 #define NEW_RETRY() rb_node_newnode(NODE_RETRY,0,0,0)
diff -up .#parse.y.1.64 parse.y
--- .#parse.y.1.64	Sat Oct 21 06:19:21 2000
+++ parse.y	Sat Oct 28 14:13:50 2000
@@ -421,6 +421,10 @@ expr		: mlhs '=' mrhs
 			    yyerror("return appeared outside of method");
 			$$ = NEW_RETURN($2);
 		    }
+		| kBREAK ret_args
+		    {
+			$$ = NEW_BREAK($2);
+		    }
 		| command_call
 		| expr kAND expr
 		    {
@@ -1292,9 +1296,18 @@ primary		: literal
 		        local_pop();
 			in_single--;
 		    }
+		| kBREAK '(' ret_args ')'
+		    {
+			value_expr($3);
+			$$ = NEW_BREAK($3);
+		    }
+		| kBREAK '(' ')'
+		    {
+			$$ = NEW_BREAK(0);
+		    }
 		| kBREAK
 		    {
-			$$ = NEW_BREAK();
+			$$ = NEW_BREAK(0);
 		    }
 		| kNEXT
 		    {
@@ -4185,8 +4198,6 @@ value_expr(node)
       case NODE_NEXT:
       case NODE_REDO:
       case NODE_RETRY:
-      case NODE_WHILE:
-      case NODE_UNTIL:
       case NODE_CLASS:
       case NODE_MODULE:
       case NODE_DEFN:
diff -up .#ruby.h.1.27 ruby.h
--- .#ruby.h.1.27	Mon Oct 16 23:19:17 2000
+++ ruby.h	Sat Oct 28 14:04:56 2000
@@ -456,6 +456,7 @@ void rb_raise __((VALUE, const char*, ..
 void rb_fatal __((const char*, ...)) NORETURN;
 void rb_bug __((const char*, ...)) NORETURN;
 void rb_sys_fail _((const char*)) NORETURN;
+void rb_break _((VALUE)) NORETURN;
 void rb_iter_break _((void)) NORETURN;
 void rb_exit _((int)) NORETURN;
 void rb_notimplement _((void)) NORETURN;


-- 
--- 僕の前にBugはない。
--- 僕の後ろにBugはできる。
    中田 伸悦