From 0e3d292739e9ee4e2010941243e181f7ea1177b6 Mon Sep 17 00:00:00 2001
From: Zhifei Fang <facetothefate@gmail.com>
Date: Tue, 9 Feb 2016 11:57:35 -0500
Subject: [PATCH 1/2] Add detail grammar error output

Add detail grammar error output, which will help developer find the yacc
grammar error quickly.
---
 lib/cli.js | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/cli.js b/lib/cli.js
index 338a23827..9342867ae 100755
--- a/lib/cli.js
+++ b/lib/cli.js
@@ -168,6 +168,7 @@ cli.processGrammars = function processGrammars(file, lexFile, jsonMode) {
             grammar = ebnfParser.parse(file);
         }
     } catch (e) {
+        console.log(e);
         throw new Error('Could not parse jison grammar');
     }
     try {
@@ -175,6 +176,7 @@ cli.processGrammars = function processGrammars(file, lexFile, jsonMode) {
             grammar.lex = require('lex-parser').parse(lexFile);
         }
     } catch (e) {
+        console.log(e);
         throw new Error('Could not parse lex grammar');
     }
     return grammar;

From 5f4344dbea04364c5d7514d3b20fab90e57d5620 Mon Sep 17 00:00:00 2001
From: Zhifei Fang <facetothefate@gmail.com>
Date: Tue, 9 Feb 2016 16:55:01 -0500
Subject: [PATCH 2/2] add the parse error to the exception message

---
 lib/cli.js | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/lib/cli.js b/lib/cli.js
index 9342867ae..d03381d2d 100755
--- a/lib/cli.js
+++ b/lib/cli.js
@@ -168,16 +168,14 @@ cli.processGrammars = function processGrammars(file, lexFile, jsonMode) {
             grammar = ebnfParser.parse(file);
         }
     } catch (e) {
-        console.log(e);
-        throw new Error('Could not parse jison grammar');
+        throw new Error(e.message + '\nCould not parse jison grammar.');
     }
     try {
         if (lexFile) {
             grammar.lex = require('lex-parser').parse(lexFile);
         }
     } catch (e) {
-        console.log(e);
-        throw new Error('Could not parse lex grammar');
+        throw new Error(e.message + '\nCould not parse lex grammar.');
     }
     return grammar;
 };