* eval.c (massign): removed awkward conversion between yvalue,

  mvalue, etc.

* eval.c (rb_yield_0): new parameter added to tell whether val is
  an array value or not.

* parse.y (yield_args): restructuring: new nodes: NODE_RESTARY2,
  NODE_SVALUE; removed node: NODE_RESTARGS.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@3269 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

5 files changed, 185 insertions, 213 deletions

diff --git a/ChangeLog b/ChangeLog
index 735895e14e..516aef14ec 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -5,6 +5,17 @@ Wed Jan  1 04:16:18 2003  Akinori MUSHA  <knu@iDaemons.org>
 	  sizeof(int) != sizeof(long) and the byte order is big-endian.
 	  This fixes breakage on FreeBSD/sparc64.
 
+Tue Dec 31 23:22:50 2002  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* eval.c (massign): removed awkward conversion between yvalue,
+	  mvalue, etc.
+
+	* eval.c (rb_yield_0): new parameter added to tell whether val is
+	  an array value or not.
+
+	* parse.y (yield_args): restructuring: new nodes: NODE_RESTARY2,
+	  NODE_SVALUE; removed node: NODE_RESTARGS.
+
 Tue Dec 31 21:13:51 2002  WATANABE Hirofumi  <eban@ruby-lang.org>
 
 	* Makefile.in, {win32,bcc32}/Makefile.sub: add new target:
diff --git a/eval.c b/eval.c
index 1c32855f8f..b451a91251 100644
--- a/eval.c
+++ b/eval.c
@@ -905,7 +905,7 @@ static VALUE rb_eval _((VALUE,NODE*));
 static VALUE eval _((VALUE,VALUE,VALUE,char*,int));
 static NODE *compile _((VALUE, char*, int));
 
-static VALUE rb_yield_0 _((VALUE, VALUE, VALUE, int));
+static VALUE rb_yield_0 _((VALUE, VALUE, VALUE, int, int));
 static VALUE rb_call _((VALUE,VALUE,ID,int,const VALUE*,int));
 static VALUE module_setup _((VALUE,NODE*));
 
@@ -2157,82 +2157,61 @@ call_trace_func(event, node, self, id, klass)
 }
 
 static VALUE
-svalue_to_avalue(v)
+mrhs_to_svalue(v)
     VALUE v;
 {
-    if (NIL_P(v)) return rb_ary_new2(0);
-    if (v == Qundef) return rb_ary_new2(0);
-    if (TYPE(v) == T_ARRAY) {
-	if (RARRAY(v)->len > 1) return v;
-	return rb_ary_new3(1, v);
-    }
-    else {
-	v = rb_ary_to_ary(v);
-    }
-    return v;
-}
-
-static VALUE
-avalue_to_svalue(v)
-    VALUE v;
-{
-    if (TYPE(v) != T_ARRAY) {
-	v = rb_ary_to_ary(v);
-    }
-    if (RARRAY(v)->len == 0) {
-	return Qnil;
-    }
-    if (RARRAY(v)->len == 1) {
-	return RARRAY(v)->ptr[0];
-    }
-    return v;
-}
+    VALUE tmp;
 
-static VALUE
-avalue_to_yvalue(v)
-    VALUE v;
-{
-    if (TYPE(v) != T_ARRAY) {
-	v = rb_ary_to_ary(v);
+    if (v == Qundef) return v;
+    tmp = rb_check_array_type(v);
+    if (NIL_P(tmp)) {
+	return v;
     }
-    if (RARRAY(v)->len == 0) {
+    if (RARRAY(tmp)->len == 0) {
 	return Qundef;
     }
-    if (RARRAY(v)->len == 1) {
-	return RARRAY(v)->ptr[0];
+    if (RARRAY(tmp)->len == 1) {
+	return RARRAY(tmp)->ptr[0];
     }
-    return v;
+    return tmp;
 }
 
 static VALUE
-svalue_to_mvalue(v)
+mrhs_to_avalue(v)
     VALUE v;
 {
-    if (v == Qnil || v == Qundef)
-	return rb_ary_new2(0);
-    if (TYPE(v) == T_ARRAY) {
-	return v;
-    }
-    else {
-	v = rb_ary_to_ary(v);
+    VALUE tmp;
+
+    if (v == Qundef) return rb_ary_new2(0);
+    tmp = rb_check_array_type(v);
+
+    if (NIL_P(tmp)) {
+	return rb_ary_new3(1, v);
     }
     return v;
 }
 
 static VALUE
-mvalue_to_svalue(v)
+args_to_svalue(v)
     VALUE v;
 {
-    if (TYPE(v) != T_ARRAY) {
-	v = rb_ary_to_ary(v);
+    VALUE tmp;
+
+    if (v == Qundef) return v;
+    tmp = rb_check_array_type(v);
+    if (NIL_P(tmp)) {
+	return v;
     }
-    if (RARRAY(v)->len == 0) {
-	return Qnil;
+    if (RARRAY(tmp)->len == 0) {
+	return Qundef;
     }
-    if (RARRAY(v)->len == 1 && TYPE(RARRAY(v)->ptr[0]) != T_ARRAY) {
-	return RARRAY(v)->ptr[0];
+    if (RARRAY(tmp)->len == 1) {
+	v = rb_check_array_type(tmp);
+	if (NIL_P(v)) {
+	    return RARRAY(tmp)->ptr[0];
+	}
     }
-    return v;
+    return tmp;
 }
 
 static void return_check _((void));
@@ -2557,23 +2536,13 @@ rb_eval(self, n)
 	break;
 
       case NODE_BREAK:
-	if (node->nd_stts) {
- 	    return_value(avalue_to_svalue(rb_eval(self, node->nd_stts)));
- 	}
-	else {
-	    return_value(Qnil);
-	}
+	return_value(rb_eval(self, node->nd_stts));
 	JUMP_TAG(TAG_BREAK);
 	break;
 
       case NODE_NEXT:
 	CHECK_INTS;
-	if (node->nd_stts) {
- 	    return_value(avalue_to_svalue(rb_eval(self, node->nd_stts)));
- 	}
-	else {
-	    return_value(Qnil);
-	}
+	return_value(rb_eval(self, node->nd_stts));
 	JUMP_TAG(TAG_NEXT);
 	break;
 
@@ -2587,24 +2556,29 @@ rb_eval(self, n)
 	JUMP_TAG(TAG_RETRY);
 	break;
 
-      case NODE_RESTARGS:
       case NODE_RESTARY:
+      case NODE_RESTARY2:
 	result = rb_ary_to_ary(rb_eval(self, node->nd_head));
 	break;
 
       case NODE_REXPAND:
-	result = avalue_to_svalue(rb_eval(self, node->nd_head));
+	result = mrhs_to_svalue(rb_eval(self, node->nd_head));
+	break;
+
+      case NODE_SVALUE:
+	result = rb_eval(self, node->nd_head);
+	if (result == Qundef) result = Qnil;
 	break;
 
       case NODE_YIELD:
 	if (node->nd_stts) {
-	    result = avalue_to_yvalue(rb_eval(self, node->nd_stts));
+	    result = rb_eval(self, node->nd_head);
 	}
 	else {
 	    result = Qundef;	/* no arg */
 	}
 	SET_CURRENT_SOURCE();
-	result = rb_yield_0(result, 0, 0, 0);
+	result = rb_yield_0(result, 0, 0, 0, 0);
 	break;
 
       case NODE_RESCUE:
@@ -2742,12 +2716,7 @@ rb_eval(self, n)
 	break;
 
       case NODE_RETURN:
-	if (node->nd_stts) {
- 	    return_value(avalue_to_svalue(rb_eval(self, node->nd_stts)));
- 	}
-	else {
-	    return_value(Qnil);
-	}
+	return_value(rb_eval(self, node->nd_stts));
 	return_check();
 	JUMP_TAG(TAG_RETURN);
 	break;
@@ -2958,7 +2927,7 @@ rb_eval(self, n)
 	break;
 
       case NODE_MASGN:
-	result = massign(self, node, rb_eval(self, node->nd_value),0);
+	result = massign(self, node, rb_eval(self, node->nd_value), 0);
 	break;
 
       case NODE_LASGN:
@@ -3826,9 +3795,9 @@ rb_f_block_given_p()
 }
 
 static VALUE
-rb_yield_0(val, self, klass, pcall)
+rb_yield_0(val, self, klass, pcall, avalue)
     VALUE val, self, klass;	/* OK */
-    int pcall;
+    int pcall, avalue;
 {
     NODE *node;
     volatile VALUE result = Qnil;
@@ -3889,18 +3858,14 @@ rb_yield_0(val, self, klass, pcall)
 		massign(self, block->var, val, pcall);
 	    }
 	    else {
-		if (pcall) {
-		    val = avalue_to_yvalue(val);
-		}
+		if (avalue) val = mrhs_to_svalue(val);
+		if (val == Qundef) val = Qnil;
 		assign(self, block->var, val, pcall);
 	    }
 	}
 	POP_TAG();
 	if (state) goto pop_state;
     }
-    else if (pcall) {
-	val = avalue_to_yvalue(val);
-    }
 
     PUSH_ITER(block->iter);
     PUSH_TAG(PROT_NONE);
@@ -3981,14 +3946,14 @@ VALUE
 rb_yield(val)
     VALUE val;
 {
-    return rb_yield_0(val, 0, 0, 0);
+    return rb_yield_0(val, 0, 0, 0, 0);
 }
 
 static VALUE
 rb_f_loop()
 {
     for (;;) {
-	rb_yield_0(Qundef, 0, 0, 0);
+	rb_yield_0(Qundef, 0, 0, 0, 0);
 	CHECK_INTS;
     }
     return Qnil;		/* dummy */
@@ -4004,9 +3969,7 @@ massign(self, node, val, pcall)
     NODE *list;
     long i = 0, len;
 
-    if (!pcall) {
-	val = svalue_to_mvalue(val);
-    }
+    val = mrhs_to_avalue(val);
     len = RARRAY(val)->len;
     list = node->nd_head;
     for (i=0; list && i<len; i++) {
@@ -4095,7 +4058,7 @@ assign(self, lhs, val, pcall)
 	break;
 
       case NODE_MASGN:
-	massign(self, lhs, svalue_to_mvalue(val), pcall);
+	massign(self, lhs, val, pcall);
 	break;
 
       case NODE_CALL:
@@ -5329,7 +5292,7 @@ static VALUE
 yield_under_i(self)
     VALUE self;
 {
-    return rb_yield_0(self, self, ruby_class, 0);
+    return rb_yield_0(self, self, ruby_class, 0, 0);
 }
 
 /* block eval under the class/module context */
@@ -6620,14 +6583,11 @@ proc_invoke(proc, args, pcall, self)
     PUSH_ITER(ITER_CUR);
     ruby_frame->iter = ITER_CUR;
 
-    if (!pcall) {
-	args = avalue_to_yvalue(args);
-    }
     PUSH_TAG(PROT_NONE);
     state = EXEC_TAG();
     if (state == 0) {
 	proc_set_safe_level(proc);
-	result = rb_yield_0(args, self, self!=Qundef?CLASS_OF(self):0, pcall);
+	result = rb_yield_0(args, self, self!=Qundef?CLASS_OF(self):0, pcall, Qtrue);
     }
     POP_TAG();
 
@@ -7167,7 +7127,6 @@ static VALUE
 bmcall(args, method)
     VALUE args, method;
 {
-    args = svalue_to_avalue(args);
     return method_call(RARRAY(args)->len, RARRAY(args)->ptr, method);
 }
 
@@ -8951,7 +8910,7 @@ rb_thread_yield(arg, th)
     rb_dvar_push('~', Qnil);
     ruby_block->dyna_vars = ruby_dyna_vars;
 
-    return rb_yield_0(mvalue_to_svalue(arg), 0, 0, Qtrue);
+    return rb_yield_0(arg, 0, 0, Qtrue, Qtrue);
 }
 
 static VALUE
@@ -9546,7 +9505,7 @@ rb_f_catch(dmy, tag)
     t = rb_to_id(tag);
     PUSH_TAG(t);
     if ((state = EXEC_TAG()) == 0) {
-	val = rb_yield_0(tag, 0, 0, 0);
+	val = rb_yield_0(tag, 0, 0, 0, Qfalse);
     }
     else if (state == TAG_THROW && t == prot_tag->dst) {
 	val = prot_tag->retval;
diff --git a/node.h b/node.h
index 74a462a98a..24964c3a1e 100644
--- a/node.h
+++ b/node.h
@@ -87,9 +87,10 @@ enum node_type {
     NODE_ARGS,
     NODE_ARGSCAT,
     NODE_ARGSPUSH,
-    NODE_RESTARGS,
     NODE_RESTARY,
+    NODE_RESTARY2,
     NODE_REXPAND,
+    NODE_SVALUE,
     NODE_BLOCK_ARG,
     NODE_BLOCK_PASS,
     NODE_DEFN,
@@ -306,9 +307,10 @@ typedef struct RNode {
 #define NEW_ARGS(f,o,r) rb_node_newnode(NODE_ARGS,o,r,f)
 #define NEW_ARGSCAT(a,b) rb_node_newnode(NODE_ARGSCAT,a,b,0)
 #define NEW_ARGSPUSH(a,b) rb_node_newnode(NODE_ARGSPUSH,a,b,0)
-#define NEW_RESTARGS(a) rb_node_newnode(NODE_RESTARGS,a,0,0)
 #define NEW_RESTARY(a) rb_node_newnode(NODE_RESTARY,a,0,0)
+#define NEW_RESTARY2(a) rb_node_newnode(NODE_RESTARY2,a,0,0)
 #define NEW_REXPAND(a) rb_node_newnode(NODE_REXPAND,a,0,0)
+#define NEW_SVALUE(a) rb_node_newnode(NODE_SVALUE,a,0,0)
 #define NEW_BLOCK_ARG(v) rb_node_newnode(NODE_BLOCK_ARG,v,0,local_cnt(v))
 #define NEW_BLOCK_PASS(b) rb_node_newnode(NODE_BLOCK_PASS,0,b,0)
 #define NEW_ALIAS(n,o) rb_node_newnode(NODE_ALIAS,o,n,0)
diff --git a/parse.y b/parse.y
index 664914552c..b2a835e4b7 100644
--- a/parse.y
+++ b/parse.y
@@ -137,6 +137,7 @@ static NODE *new_evstr();
 static NODE *call_op();
 static int in_defined = 0;
 
+static NODE *yield_args();
 static NODE *ret_args();
 static NODE *arg_blk_pass();
 static NODE *new_call();
@@ -245,7 +246,7 @@ static void top_local_setup();
 %type <node> if_tail opt_else case_body cases opt_rescue exc_list exc_var opt_ensure
 %type <node> args when_args call_args call_args2 open_args paren_args opt_paren_args
 %type <node> command_args aref_args opt_block_arg block_arg var_ref var_lhs
-%type <node> mrhs mrhs_basic superclass block_call block_command
+%type <node> mrhs superclass block_call block_command
 %type <node> f_arglist f_args f_optarg f_opt f_block_arg opt_f_block_arg
 %type <node> assoc_list assocs assoc undef_list backref string_dvar
 %type <node> block_var opt_block_var brace_block cmd_brace_block do_block lhs none
@@ -460,7 +461,7 @@ stmt		: kALIAS fitem {lex_state = EXPR_FNAME;} fitem
 		| mlhs '=' command_call
 		    {
 			value_expr($3);
-			$1->nd_value = $3;
+			$1->nd_value = NEW_RESTARY($3);
 			$$ = $1;
 		    }
 		| var_lhs tOP_ASGN command_call
@@ -546,9 +547,14 @@ stmt		: kALIAS fitem {lex_state = EXPR_FNAME;} fitem
 		        rb_backref_error($1);
 			$$ = 0;
 		    }
-		| lhs '=' mrhs_basic
+		| lhs '=' mrhs
+		    {
+			$$ = node_assign($1, NEW_SVALUE($3));
+		    }
+		| mlhs '=' arg_value
 		    {
-			$$ = node_assign($1, NEW_REXPAND($3));
+			$1->nd_value = NEW_RESTARY($3);
+			$$ = $1;
 		    }
 		| mlhs '=' mrhs
 		    {
@@ -689,7 +695,7 @@ command		: operation command_args       %prec tLOWEST
 		    }
 		| kYIELD command_args
 		    {
-			$$ = NEW_YIELD(ret_args($2));
+			$$ = NEW_YIELD(yield_args($2));
 		        fixpos($$, $2);
 		    }
 		;
@@ -1147,7 +1153,7 @@ aref_args	: none
 		| tSTAR arg opt_nl
 		    {
 			value_expr($2);
-			$$ = NEW_RESTARY($2);
+			$$ = NEW_RESTARY2($2);
 		    }
 		;
 
@@ -1212,7 +1218,7 @@ call_args	: command
 		    }
 		| tSTAR arg_value opt_block_arg
 		    {
-			$$ = arg_blk_pass(NEW_RESTARGS($2), $3);
+			$$ = arg_blk_pass(NEW_RESTARY($2), $3);
 		    }
 		| block_arg
 		;
@@ -1267,7 +1273,7 @@ call_args2	: arg_value ',' args opt_block_arg
 		    }
 		| tSTAR arg_value opt_block_arg
 		    {
-			$$ = arg_blk_pass(NEW_RESTARGS($2), $3);
+			$$ = arg_blk_pass(NEW_RESTARY($2), $3);
 		    }
 		| block_arg
 		;
@@ -1322,17 +1328,7 @@ args 		: arg_value
 		    }
 		;
 
-mrhs		: arg_value
-		    {
-			$$ = $1;
-		    }
-		| mrhs_basic
-		    {
-			$$ = NEW_REXPAND($1);
-		    }
-		;
-
-mrhs_basic	: args ',' arg_value
+mrhs		: args ',' arg_value
 		    {
 			$$ = list_append($1, $3);
 		    }
@@ -1342,7 +1338,7 @@ mrhs_basic	: args ',' arg_value
 		    }
 		| tSTAR arg_value
 		    {
-			$$ = $2;
+			$$ = NEW_REXPAND($2);
 		    }
 		;
 
@@ -1408,7 +1404,7 @@ primary		: literal
 		    }
 		| kYIELD '(' call_args ')'
 		    {
-			$$ = NEW_YIELD(ret_args($3));
+			$$ = NEW_YIELD(yield_args($3));
 		    }
 		| kYIELD '(' ')'
 		    {
@@ -4765,7 +4761,7 @@ rb_backref_error(node)
 	rb_compile_error("Can't set variable $%d", node->nd_nth);
 	break;
       case NODE_BACK_REF:
-	rb_compile_error("Can't set variable $%c", node->nd_nth);
+	rb_compile_error("Can't set variable $%c", (int)node->nd_nth);
 	break;
     }
 }
@@ -5198,6 +5194,20 @@ ret_args(node)
 	if (nd_type(node) == NODE_BLOCK_PASS) {
 	    rb_compile_error("block argument should not be given");
 	}
+	if (nd_type(node) == NODE_ARRAY && node->nd_next == 0) {
+	    node = node->nd_head;
+	}
+    }
+    return node;
+}
+
+static NODE *
+yield_args(node)
+    NODE *node;
+{
+    node = ret_args(node);
+    if (node && nd_type(node) == NODE_RESTARY) {
+	nd_set_type(node, NODE_REXPAND);
     }
     return node;
 }
@@ -5222,7 +5232,8 @@ arg_prepend(node1, node2)
       case NODE_ARRAY:
 	return list_concat(NEW_LIST(node1), node2);
 
-      case NODE_RESTARGS:
+      case NODE_RESTARY:
+      case NODE_RESTARY2:
 	return arg_concat(node1, node2->nd_head);
 
       case NODE_BLOCK_PASS:
diff --git a/sample/test.rb b/sample/test.rb
index b16d7779c1..f8a3eb447e 100644
--- a/sample/test.rb
+++ b/sample/test.rb
@@ -48,6 +48,7 @@ a = []; test_ok(a == [])
 a = [1]; test_ok(a == [1])
 a = [nil]; test_ok(a == [nil])
 a = [[]]; test_ok(a == [[]])
+a = [1,2]; test_ok(a == [1,2])
 a = [*[]]; test_ok(a == [])
 a = [*[1]]; test_ok(a == [1])
 a = [*[1,2]]; test_ok(a == [1,2])
@@ -58,50 +59,56 @@ a = *[]; test_ok(a == nil)
 a = *[1]; test_ok(a == 1)
 a = *[nil]; test_ok(a == nil)
 a = *[[]]; test_ok(a == [])
+a = *[1,2]; test_ok(a == [1,2])
 a = *[*[]]; test_ok(a == nil)
 a = *[*[1]]; test_ok(a == 1)
 a = *[*[1,2]]; test_ok(a == [1,2])
 
-*a = nil; test_ok(a == [])
+*a = nil; test_ok(a == [nil])
 *a = 1; test_ok(a == [1])
 *a = []; test_ok(a == [])
 *a = [1]; test_ok(a == [1])
 *a = [nil]; test_ok(a == [nil])
 *a = [[]]; test_ok(a == [[]])
+*a = [1,2]; test_ok(a == [1,2])
 *a = [*[]]; test_ok(a == [])
 *a = [*[1]]; test_ok(a == [1])
 *a = [*[1,2]]; test_ok(a == [1,2])
 
-*a = *nil; test_ok(a == [])
+*a = *nil; test_ok(a == [nil])
 *a = *1; test_ok(a == [1])
 *a = *[]; test_ok(a == [])
 *a = *[1]; test_ok(a == [1])
-*a = *[nil]; test_ok(a == [])
+*a = *[nil]; test_ok(a == [nil])
 *a = *[[]]; test_ok(a == [])
+*a = *[1,2]; test_ok(a == [1,2])
 *a = *[*[]]; test_ok(a == [])
 *a = *[*[1]]; test_ok(a == [1])
 *a = *[*[1,2]]; test_ok(a == [1,2])
 
-a,b,*c = nil; test_ok([a,b,c] == [nil, nil, []])
-a,b,*c = 1; test_ok([a,b,c] == [1, nil, []])
-a,b,*c = []; test_ok([a,b,c] == [nil, nil, []])
-a,b,*c = [1]; test_ok([a,b,c] == [1, nil, []])
-a,b,*c = [nil]; test_ok([a,b,c] == [nil, nil, []])
-a,b,*c = [[]]; test_ok([a,b,c] == [[], nil, []])
-a,b,*c = [*[]]; test_ok([a,b,c] == [nil, nil, []])
-a,b,*c = [*[1]]; test_ok([a,b,c] == [1, nil, []])
-a,b,*c = [*[1,2]]; test_ok([a,b,c] == [1, 2, []])
-
-a,b,*c = *nil; test_ok([a,b,c] == [nil, nil, []])
-a,b,*c = *1; test_ok([a,b,c] == [1, nil, []])
-a,b,*c = *[]; test_ok([a,b,c] == [nil, nil, []])
-a,b,*c = *[1]; test_ok([a,b,c] == [1, nil, []])
-a,b,*c = *[nil]; test_ok([a,b,c] == [nil, nil, []])
-a,b,*c = *[[]]; test_ok([a,b,c] == [nil, nil, []])
-a,b,*c = *[*[]]; test_ok([a,b,c] == [nil, nil, []])
-a,b,*c = *[*[1]]; test_ok([a,b,c] == [1, nil, []])
-a,b,*c = *[*[1,2]]; test_ok([a,b,c] == [1, 2, []])
-
+a,b,*c = nil; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = 1; test_ok([a,b,c] == [1,nil,[]])
+a,b,*c = []; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = [1]; test_ok([a,b,c] == [1,nil,[]])
+a,b,*c = [nil]; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = [[]]; test_ok([a,b,c] == [[],nil,[]])
+a,b,*c = [1,2]; test_ok([a,b,c] == [1,2,[]])
+a,b,*c = [*[]]; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = [*[1]]; test_ok([a,b,c] == [1,nil,[]])
+a,b,*c = [*[1,2]]; test_ok([a,b,c] == [1,2,[]])
+
+a,b,*c = *nil; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = *1; test_ok([a,b,c] == [1,nil,[]])
+a,b,*c = *[]; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = *[1]; test_ok([a,b,c] == [1,nil,[]])
+a,b,*c = *[nil]; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = *[[]]; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = *[1,2]; test_ok([a,b,c] == [1,2,[]])
+a,b,*c = *[*[]]; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = *[*[1]]; test_ok([a,b,c] == [1,nil,[]])
+a,b,*c = *[*[1,2]]; test_ok([a,b,c] == [1,2,[]])
+
+def f; yield; end; f {|a| test_ok(a == nil)}
 def f; yield nil; end; f {|a| test_ok(a == nil)}
 def f; yield 1; end; f {|a| test_ok(a == 1)}
 def f; yield []; end; f {|a| test_ok(a == [])}
@@ -122,7 +129,8 @@ def f; yield *[*[]]; end; f {|a| test_ok(a == nil)}
 def f; yield *[*[1]]; end; f {|a| test_ok(a == 1)}
 def f; yield *[*[1,2]]; end; f {|a| test_ok(a == [1,2])}
 
-def f; yield nil; end; f {|*a| test_ok(a == [])}
+def f; yield; end; f {|*a| test_ok(a == [])}
+def f; yield nil; end; f {|*a| test_ok(a == [nil])}
 def f; yield 1; end; f {|*a| test_ok(a == [1])}
 def f; yield []; end; f {|*a| test_ok(a == [])}
 def f; yield [1]; end; f {|*a| test_ok(a == [1])}
@@ -132,35 +140,36 @@ def f; yield [*[]]; end; f {|*a| test_ok(a == [])}
 def f; yield [*[1]]; end; f {|*a| test_ok(a == [1])}
 def f; yield [*[1,2]]; end; f {|*a| test_ok(a == [1,2])}
 
-def f; yield *nil; end; f {|*a| test_ok(a == [])}
+def f; yield *nil; end; f {|*a| test_ok(a == [nil])}
 def f; yield *1; end; f {|*a| test_ok(a == [1])}
 def f; yield *[]; end; f {|*a| test_ok(a == [])}
 def f; yield *[1]; end; f {|*a| test_ok(a == [1])}
-def f; yield *[nil]; end; f {|*a| test_ok(a == [])}
+def f; yield *[nil]; end; f {|*a| test_ok(a == [nil])}
 def f; yield *[[]]; end; f {|*a| test_ok(a == [])}
 def f; yield *[*[]]; end; f {|*a| test_ok(a == [])}
 def f; yield *[*[1]]; end; f {|*a| test_ok(a == [1])}
 def f; yield *[*[1,2]]; end; f {|*a| test_ok(a == [1,2])}
 
-def f; yield nil; end; f {|a,b,*c| test_ok([a,b,c] == [nil, nil, []])}
-def f; yield 1; end; f {|a,b,*c| test_ok([a,b,c] == [1, nil, []])}
-def f; yield []; end; f {|a,b,*c| test_ok([a,b,c] == [nil, nil, []])}
-def f; yield [1]; end; f {|a,b,*c| test_ok([a,b,c] == [1, nil, []])}
-def f; yield [nil]; end; f {|a,b,*c| test_ok([a,b,c] == [nil, nil, []])}
-def f; yield [[]]; end; f {|a,b,*c| test_ok([a,b,c] == [[], nil, []])}
-def f; yield [*[]]; end; f {|a,b,*c| test_ok([a,b,c] == [nil, nil, []])}
-def f; yield [*[1]]; end; f {|a,b,*c| test_ok([a,b,c] == [1, nil, []])}
-def f; yield [*[1,2]]; end; f {|a,b,*c| test_ok([a,b,c] == [1, 2, []])}
-
-def f; yield *nil; end; f {|a,b,*c| test_ok([a,b,c] == [nil, nil, []])}
-def f; yield *1; end; f {|a,b,*c| test_ok([a,b,c] == [1, nil, []])}
-def f; yield *[]; end; f {|a,b,*c| test_ok([a,b,c] == [nil, nil, []])}
-def f; yield *[1]; end; f {|a,b,*c| test_ok([a,b,c] == [1, nil, []])}
-def f; yield *[nil]; end; f {|a,b,*c| test_ok([a,b,c] == [nil, nil, []])}
-def f; yield *[[]]; end; f {|a,b,*c| test_ok([a,b,c] == [nil, nil, []])}
-def f; yield *[*[]]; end; f {|a,b,*c| test_ok([a,b,c] == [nil, nil, []])}
-def f; yield *[*[1]]; end; f {|a,b,*c| test_ok([a,b,c] == [1, nil, []])}
-def f; yield *[*[1,2]]; end; f {|a,b,*c| test_ok([a,b,c] == [1, 2, []])}
+def f; yield; end; f {|a,b,*c| test_ok([a,b,c] == [nil,nil,[]])}
+def f; yield nil; end; f {|a,b,*c| test_ok([a,b,c] == [nil,nil,[]])}
+def f; yield 1; end; f {|a,b,*c| test_ok([a,b,c] == [1,nil,[]])}
+def f; yield []; end; f {|a,b,*c| test_ok([a,b,c] == [nil,nil,[]])}
+def f; yield [1]; end; f {|a,b,*c| test_ok([a,b,c] == [1,nil,[]])}
+def f; yield [nil]; end; f {|a,b,*c| test_ok([a,b,c] == [nil,nil,[]])}
+def f; yield [[]]; end; f {|a,b,*c| test_ok([a,b,c] == [[],nil,[]])}
+def f; yield [*[]]; end; f {|a,b,*c| test_ok([a,b,c] == [nil,nil,[]])}
+def f; yield [*[1]]; end; f {|a,b,*c| test_ok([a,b,c] == [1,nil,[]])}
+def f; yield [*[1,2]]; end; f {|a,b,*c| test_ok([a,b,c] == [1,2,[]])}
+
+def f; yield *nil; end; f {|a,b,*c| test_ok([a,b,c] == [nil,nil,[]])}
+def f; yield *1; end; f {|a,b,*c| test_ok([a,b,c] == [1,nil,[]])}
+def f; yield *[]; end; f {|a,b,*c| test_ok([a,b,c] == [nil,nil,[]])}
+def f; yield *[1]; end; f {|a,b,*c| test_ok([a,b,c] == [1,nil,[]])}
+def f; yield *[nil]; end; f {|a,b,*c| test_ok([a,b,c] == [nil,nil,[]])}
+def f; yield *[[]]; end; f {|a,b,*c| test_ok([a,b,c] == [nil,nil,[]])}
+def f; yield *[*[]]; end; f {|a,b,*c| test_ok([a,b,c] == [nil,nil,[]])}
+def f; yield *[*[1]]; end; f {|a,b,*c| test_ok([a,b,c] == [1,nil,[]])}
+def f; yield *[*[1,2]]; end; f {|a,b,*c| test_ok([a,b,c] == [1,2,[]])}
 
 test_check "condition"
 
@@ -679,48 +688,28 @@ class IterTest
 end
 IterTest.new(nil).method(:f).to_proc.call([1])
 
-IterTest.new([0]).each0 { |x| $x = x }
-test_ok($x == 0)
-IterTest.new([1]).each1 { |x| $x = x }
-test_ok($x == 1)
-IterTest.new([2]).each2 { |x| $x = x }
-test_ok($x == [2])
-IterTest.new([3]).each3 { |x| $x = x }
-test_ok($x == 3)
-IterTest.new([4]).each4 { |x| $x = x }
-test_ok($x == 4)
-IterTest.new([5]).each5 { |x| $x = x }
-test_ok($x == 5)
-IterTest.new([6]).each6 { |x| $x = x }
-test_ok($x == [6])
-IterTest.new([7]).each7 { |x| $x = x }
-test_ok($x == 7)
-IterTest.new([8]).each8 { |x| $x = x }
-test_ok($x == 8)
-
-IterTest.new([[0]]).each0 { |x| $x = x }
-test_ok($x == [0])
-IterTest.new([[1]]).each1 { |x| $x = x }
-test_ok($x == 1)
-IterTest.new([[2]]).each2 { |x| $x = x }
-test_ok($x == [2])
-IterTest.new([[3]]).each3 { |x| $x = x }
-test_ok($x == 3)
-IterTest.new([[4]]).each4 { |x| $x = x }
-test_ok($x == [4])
-IterTest.new([[5]]).each5 { |x| $x = x }
-test_ok($x == 5)
-IterTest.new([[6]]).each6 { |x| $x = x }
-test_ok($x == [6])
-IterTest.new([[7]]).each7 { |x| $x = x }
-test_ok($x == 7)
-IterTest.new([[8]]).each8 { |x| $x = x }
-test_ok($x == [8])
-
-IterTest.new([[0,0]]).each0 { |x| $x = x }
-test_ok($x == [0,0])
-IterTest.new([[8,8]]).each8 { |x| $x = x }
-test_ok($x == [8,8])
+IterTest.new([0]).each0 { |x| test_ok(x == 0)}
+IterTest.new([1]).each1 { |x| test_ok(x == 1)}
+IterTest.new([2]).each2 { |x| test_ok(x == [2])}
+IterTest.new([3]).each3 { |x| test_ok(x == 3)}
+IterTest.new([4]).each4 { |x| test_ok(x == 4)}
+IterTest.new([5]).each5 { |x| test_ok(x == 5)}
+IterTest.new([6]).each6 { |x| test_ok(x == [6])}
+IterTest.new([7]).each7 { |x| test_ok(x == 7)}
+IterTest.new([8]).each8 { |x| test_ok(x == 8)}
+
+IterTest.new([[0]]).each0 { |x| test_ok(x == [0])}
+IterTest.new([[1]]).each1 { |x| test_ok(x == 1)}
+IterTest.new([[2]]).each2 { |x| test_ok(x == [2])}
+IterTest.new([[3]]).each3 { |x| test_ok(x == 3)}
+IterTest.new([[4]]).each4 { |x| test_ok(x == [4])}
+IterTest.new([[5]]).each5 { |x| test_ok(x == 5)}
+IterTest.new([[6]]).each6 { |x| test_ok(x == [6])}
+IterTest.new([[7]]).each7 { |x| test_ok(x == 7)}
+IterTest.new([[8]]).each8 { |x| test_ok(x == [8])}
+
+IterTest.new([[0,0]]).each0 { |x| test_ok(x == [0,0])}
+IterTest.new([[8,8]]).each8 { |x| test_ok(x == [8,8])}
 
 test_check "float"
 test_ok(2.6.floor == 2)
@@ -948,7 +937,7 @@ test_ok(a == [1, 2, 3])
 test_ok(a == [4])
 
 *a = nil
-test_ok(a == [])
+test_ok(a == [nil])
 
 test_check "call"
 def aaa(a, b=100, *rest)