should splat and iterate elements when "*ary" speficied in the case-when clause; close #1627

src/array.c

@@ -1111,6 +1111,22 @@ mrb_ary_eql(mrb_state *mrb, mrb_value ary1)
   return mrb_true_value();
 }
 
+static mrb_value
+mrb_ary_ceqq(mrb_state *mrb, mrb_value ary)
+{
+  mrb_value v;
+  mrb_int i, len;
+  mrb_sym eqq = mrb_intern_lit(mrb, "===");
+
+  mrb_get_args(mrb, "o", &v);
+  len = RARRAY_LEN(ary);
+  for (i=0; i<len; i++) {
+    mrb_value c = mrb_funcall_argv(mrb, ary_elt(ary, i), eqq, 1, &v);
+    if (mrb_test(c)) return mrb_true_value();
+  }
+  return mrb_false_value();
+}
+
 void
 mrb_init_array(mrb_state *mrb)
 {
@@ -1153,4 +1169,5 @@ mrb_init_array(mrb_state *mrb)
   mrb_define_method(mrb, a, "==",              mrb_ary_equal,        MRB_ARGS_REQ(1)); /* 15.2.12.5.33 (x) */
   mrb_define_method(mrb, a, "eql?",            mrb_ary_eql,          MRB_ARGS_REQ(1)); /* 15.2.12.5.34 (x) */
   mrb_define_method(mrb, a, "<=>",             mrb_ary_cmp,          MRB_ARGS_REQ(1)); /* 15.2.12.5.36 (x) */
+  mrb_define_method(mrb, a, "__case_eqq",      mrb_ary_ceqq,         MRB_ARGS_REQ(1)); /* internal */
 }

src/codegen.c

@@ -1386,7 +1386,12 @@ codegen(codegen_scope *s, node *tree, int val)
           if (head) {
             genop(s, MKOP_AB(OP_MOVE, cursp(), head));
             pop();
-            genop(s, MKOP_ABC(OP_SEND, cursp(), new_msym(s, mrb_intern_lit(s->mrb, "===")), 1));
+            if ((intptr_t)n->car->car == NODE_SPLAT) {
+              genop(s, MKOP_ABC(OP_SEND, cursp(), new_msym(s, mrb_intern_lit(s->mrb, "__case_eqq")), 1));
+            }
+            else {
+              genop(s, MKOP_ABC(OP_SEND, cursp(), new_msym(s, mrb_intern_lit(s->mrb, "===")), 1));
+            }
           }
           else {
             pop();
@@ -1510,7 +1515,14 @@ codegen(codegen_scope *s, node *tree, int val)
     break;
 
   case NODE_SPLAT:
-    codegen(s, tree, VAL);
+    {
+      int idx = new_msym(s, mrb_intern_lit(s->mrb, "to_a"));
+
+      codegen(s, tree, VAL);
+      pop();
+      genop(s, MKOP_ABC(OP_SEND, cursp(), idx, 0));
+      push();
+    }
     break;
 
   case NODE_ASGN: