Most of RVM desugaring done in first draft, for TQ to check.

src/parsers/int_range.c

@@ -28,10 +28,31 @@ static HParseResult* parse_int_range(void *env, HParseState *state) {
   }
 }
 
+bool h_svm_action_validate_int_range(HArena *arena, HSVMContext *ctx, void* env) {
+  HRange *r_env = (*HRange)env;
+  HParsedToken *head = ctx->stack[ctx->stack_count-1];
+  switch (head-> token_type) {
+  case TT_SINT: 
+    return head->sint >= r_env->lower && head->sint <= r_env->upper;
+  case TT_UINT: 
+    return head->uint >= (uint64_t)r_env->lower && head->uint <= (uint64_t)r_env->upper;
+  default:
+    return false;
+  }
+}
+static bool ir_ctrvm(HRVMProg *prog, void *env) {
+  HRange *r_env = (*HRange)env;
+  
+  h_compile_regex(prog, r_env->p);
+  h_rvm_insert_insn(prog, RVM_ACTION, h_rvm_create_action(prog, h_svm_action_validate_int_range, env));
+  return false;
+}
+
 static const HParserVtable int_range_vt = {
   .parse = parse_int_range,
   .isValidRegular = h_true,
   .isValidCF = h_true,
+  .compile_to_rvm = ir_ctrvm,
 };
 
 const HParser* h_int_range(const HParser *p, const int64_t lower, const int64_t upper) {