string interpolation in regex

src/codegen.c

@@ -1935,7 +1935,7 @@ codegen(codegen_scope *s, node *tree, int val)
       int ai = mrb_gc_arena_save(s->mrb);
       int sym = new_sym(s, mrb_intern(s->mrb, REGEXP_CLASS));
       int off = new_lit(s, mrb_str_new(s->mrb, p1, strlen(p1)));
-      int n = 1;
+      int argc = 1;
 
       genop(s, MKOP_A(OP_OCLASS, cursp()));
       genop(s, MKOP_ABx(OP_GETMCNST, cursp(), sym));
@@ -1945,17 +1945,75 @@ codegen(codegen_scope *s, node *tree, int val)
         push();
         off = new_lit(s, mrb_str_new(s->mrb, p2, strlen(p2)));
         genop(s, MKOP_ABx(OP_STRING, cursp(), off));
-        n++;
+        argc++;
         pop();
       }
       pop();
       sym = new_sym(s, mrb_intern(s->mrb, "compile"));
-      genop(s, MKOP_ABC(OP_SEND, cursp(), sym, n));
+      genop(s, MKOP_ABC(OP_SEND, cursp(), sym, argc));
       mrb_gc_arena_restore(s->mrb, ai); 
       push();
     }
     break;
 
+  case NODE_DREGX:
+    if (val) {
+      node *n = tree->car;
+      int ai = mrb_gc_arena_save(s->mrb);
+      int sym = new_sym(s, mrb_intern(s->mrb, REGEXP_CLASS));
+      int argc = 1;
+      int off;
+      char *p;
+
+      genop(s, MKOP_A(OP_OCLASS, cursp()));
+      genop(s, MKOP_ABx(OP_GETMCNST, cursp(), sym));
+      push();
+      codegen(s, n->car, VAL);
+      n = n->cdr;
+      while (n) {
+        codegen(s, n->car, VAL);
+        pop(); pop();
+        genop(s, MKOP_AB(OP_STRCAT, cursp(), cursp()+1));
+        push();
+        n = n->cdr;
+      }
+      n = tree->cdr->cdr;
+      if (n->car) {
+	p = (char*)n->car;
+	off = new_lit(s, mrb_str_new(s->mrb, p, strlen(p)));
+	codegen(s, tree->car, VAL);
+	genop(s, MKOP_ABx(OP_STRING, cursp(), off));
+	pop();
+	genop(s, MKOP_AB(OP_STRCAT, cursp(), cursp()+1));
+      }
+      if (n->cdr) {
+	char *p2 = (char*)n->cdr;
+	int off;
+
+        push();
+        off = new_lit(s, mrb_str_new(s->mrb, p2, strlen(p2)));
+        genop(s, MKOP_ABx(OP_STRING, cursp(), off));
+        argc++;
+        pop();
+      }
+      pop();
+      sym = new_sym(s, mrb_intern(s->mrb, "compile"));
+      genop(s, MKOP_ABC(OP_SEND, cursp(), sym, argc));
+      mrb_gc_arena_restore(s->mrb, ai); 
+      push();
+    }
+    else {
+      node *n = tree->car;
+
+      while (n) {
+        if ((intptr_t)n->car->car != NODE_STR) {
+          codegen(s, n->car, NOVAL);
+        }
+        n = n->cdr;
+      }
+    }
+    break;
+
   case NODE_SYM:
     if (val) {
       int sym = new_sym(s, sym(tree));

src/parse.y

@@ -715,6 +715,13 @@ new_regx(parser_state *p, const char *p1, const char* p2)
   return cons((node*)NODE_REGX, cons((node*)p1, (node*)p2));
 }
 
+// (:dregx . a)
+static node*
+new_dregx(parser_state *p, node *a, node *b)
+{
+  return cons((node*)NODE_DREGX, cons(a, b));
+}
+
 // (:backref . n)
 static node*
 new_back_ref(parser_state *p, int n)
@@ -2510,6 +2517,10 @@ regexp		: tREGEXP_BEG tREGEXP
 		    {
 			$$ = $2;
 		    }
+		| tREGEXP_BEG string_interp tREGEXP
+		    {
+		      $$ = new_dregx(p, $2, $3);
+		    }
 		;
 
 symbol		: basic_symbol
@@ -5502,6 +5513,15 @@ parser_dump(mrb_state *mrb, node *tree, int offset)
     printf("NODE_REGX /%s/%s\n", (char*)tree->car, (char*)tree->cdr);
     break;
 
+  case NODE_DREGX:
+    printf("NODE_DREGX\n");
+    dump_recur(mrb, tree->car, offset+1);
+    dump_prefix(offset);
+    printf("tail: %s\n", (char*)tree->cdr->cdr->car);
+    dump_prefix(offset);
+    printf("opt: %s\n", (char*)tree->cdr->cdr->cdr);
+    break;
+
   case NODE_SYM:
     printf("NODE_SYM :%s\n", mrb_sym2name(mrb, sym(tree)));
     break;