From cd8a683229d4e207075e29b4aa07f88348cd136d Mon Sep 17 00:00:00 2001
From: Max Brunsfeld <maxbrunsfeld@gmail.com>
Date: Wed, 10 Sep 2014 13:02:16 -0700
Subject: [PATCH] Improve error messages for invalid ubiquitous tokens

---
 spec/compiler/prepare_grammar/extract_tokens_spec.cc | 8 ++++++--
 src/compiler/prepare_grammar/extract_tokens.cc       | 8 ++++----
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/spec/compiler/prepare_grammar/extract_tokens_spec.cc b/spec/compiler/prepare_grammar/extract_tokens_spec.cc
index d444adef..542535ee 100644
--- a/spec/compiler/prepare_grammar/extract_tokens_spec.cc
+++ b/spec/compiler/prepare_grammar/extract_tokens_spec.cc
@@ -214,7 +214,9 @@ describe("extract_tokens", []() {
         }).ubiquitous_tokens({ i_sym(1) }));
 
         AssertThat(get<2>(result), !Equals<const GrammarError *>(nullptr));
-        AssertThat(get<2>(result), EqualsPointer(new GrammarError(GrammarErrorTypeInvalidUbiquitousToken, "Not a token: (sym 1)")));
+        AssertThat(get<2>(result), EqualsPointer(
+            new GrammarError(GrammarErrorTypeInvalidUbiquitousToken,
+                             "Not a token: rule_B")));
       });
     });
 
@@ -226,7 +228,9 @@ describe("extract_tokens", []() {
         }).ubiquitous_tokens({ choice({ i_sym(1), blank() }) }));
 
         AssertThat(get<2>(result), !Equals<const GrammarError *>(nullptr));
-        AssertThat(get<2>(result), EqualsPointer(new GrammarError(GrammarErrorTypeInvalidUbiquitousToken, "Not a token: (choice (sym 1) (blank))")));
+        AssertThat(get<2>(result), EqualsPointer(
+            new GrammarError(GrammarErrorTypeInvalidUbiquitousToken,
+                             "Not a token: (choice (sym 1) (blank))")));
       });
     });
   });
diff --git a/src/compiler/prepare_grammar/extract_tokens.cc b/src/compiler/prepare_grammar/extract_tokens.cc
index 74780186..5b416a02 100644
--- a/src/compiler/prepare_grammar/extract_tokens.cc
+++ b/src/compiler/prepare_grammar/extract_tokens.cc
@@ -92,10 +92,10 @@ class TokenExtractor : public rules::IdentityRuleFn {
 };
 
 static tuple<SyntaxGrammar, LexicalGrammar, const GrammarError *> ubiq_token_err(
-    const rule_ptr rule) {
+    const string &msg) {
   return make_tuple(SyntaxGrammar(), LexicalGrammar(),
                     new GrammarError(GrammarErrorTypeInvalidUbiquitousToken,
-                                     "Not a token: " + rule->to_string()));
+                                     "Not a token: " + msg));
 }
 
 tuple<SyntaxGrammar, LexicalGrammar, const GrammarError *> extract_tokens(
@@ -128,11 +128,11 @@ tuple<SyntaxGrammar, LexicalGrammar, const GrammarError *> extract_tokens(
     } else {
       auto sym = dynamic_pointer_cast<const Symbol>(extractor.apply(rule));
       if (!sym.get())
-        return ubiq_token_err(rule);
+        return ubiq_token_err(rule->to_string());
 
       Symbol symbol = symbol_replacer.replace_symbol(*sym);
       if (!symbol.is_token())
-        return ubiq_token_err(rule);
+        return ubiq_token_err(rules[symbol.index].first);
 
       ubiquitous_tokens.insert(symbol);
     }