fix formatting in derive_type_ident function output

Author: hackwaly

boot/moonyacc.js

@@ -27800,7 +27800,7 @@ function moonbitlang$yacc$lib$codegen$gen_mbt$$derive_type_ident(type_) {
       const _args$2 = _Arrow._0;
       const _ret = _Arrow._1;
       const _bind$2 = moonbitlang$core$array$$Array$iter$45$(_args$2);
-      return `_${moonbitlang$core$builtin$$Iter$join((_p) => _bind$2((_p$2) => _p(moonbitlang$yacc$lib$codegen$gen_mbt$$derive_type_ident(_p$2))), "__")}_ -> ${moonbitlang$yacc$lib$codegen$gen_mbt$$derive_type_ident(_ret)}`;
+      return `_${moonbitlang$core$builtin$$Iter$join((_p) => _bind$2((_p$2) => _p(moonbitlang$yacc$lib$codegen$gen_mbt$$derive_type_ident(_p$2))), "__")}_____${moonbitlang$yacc$lib$codegen$gen_mbt$$derive_type_ident(_ret)}`;
     }
   }
 }

moon.mod.json

@@ -1,6 +1,6 @@
 {
   "name": "moonbitlang/yacc",
-  "version": "0.3.31",
+  "version": "0.3.32",
   "deps": {
     "moonbitlang/x": "0.4.23",
     "Yoorkin/ArgParser": "0.1.9"

src/lib/codegen/gen_mbt/gen_mbt.mbt

@@ -74,7 +74,7 @@ fn derive_type_ident(type_ : @elab.TypeExpr) -> String {
     Arrow(args, ret) =>
       "_" +
       args.iter().map(derive_type_ident).join("__") +
-      "_ -> " +
+      "_____" +
       derive_type_ident(ret)
   }
 }