Add ERRORK opcode to trigger constant errors

src/compile.c

@@ -144,6 +144,13 @@ block gen_op_simple(opcode op) {
 }
 
 
+block gen_error(jv constant) {
+  assert(opcode_describe(ERRORK)->flags & OP_HAS_CONSTANT);
+  inst *i = inst_new(ERRORK);
+  i->imm.constant = constant;
+  return inst_block(i);
+}
+
 block gen_const(jv constant) {
   assert(opcode_describe(LOADK)->flags & OP_HAS_CONSTANT);
   inst* i = inst_new(LOADK);

src/compile.h

@@ -19,6 +19,7 @@ block gen_location(location, struct locfile*, block);
 block gen_noop();
 int block_is_noop(block b);
 block gen_op_simple(opcode op);
+block gen_error(jv constant);
 block gen_const(jv constant);
 block gen_const_global(jv constant, const char *name);
 int block_is_const(block b);

src/execute.c

@@ -405,6 +405,12 @@ jv jq_next(jq_state *jq) {
 
     case TOP: break;
 
+    case ERRORK: {
+      jv v = jv_array_get(jv_copy(frame_current(jq)->bc->constants), *pc++);
+      set_error(jq, jv_invalid_with_msg(v));
+      goto do_backtrack;
+    }
+
     case LOADK: {
       jv v = jv_array_get(jv_copy(frame_current(jq)->bc->constants), *pc++);
       assert(jv_is_valid(v));

src/opcode_list.h

@@ -47,3 +47,5 @@ OP(GENLABEL, NONE, 0, 1)
 
 OP(DESTRUCTURE_ALT, BRANCH, 0, 0)
 OP(STOREVN, VARIABLE, 1, 0)
+
+OP(ERRORK, CONSTANT, 1, 0)