Convert to jison.

package.json

@@ -1,15 +1,15 @@
 {
   "name": "zerkel",
-  "version": "1.1.0",
+  "version": "1.2.0",
   "description": "A compiler for the zerkel language",
   "dependencies": {
-    "coffee-script": "1.6.3",
+    "coffee-script": "1.7.1",
     "browserify": "2.22.0"
   },
   "devDependencies": {
     "chai": "1.2.0",
     "mocha": "1.4.0",
-    "pegjs": "0.7.0"
+    "jison": "0.4.13"
   },
   "scripts": {
     "test": "node_modules/.bin/mocha -R dot"

src/zerkel-parser.jison

@@ -0,0 +1,67 @@
+/* lexical grammar */
+%lex
+%%
+\s+                   {/* skip whitespace */}
+"and"|"AND"           {return 'AND';}
+"or"|"OR"             {return 'OR';}
+"not"|"NOT"           {return 'NOT';}
+"="                   {return '=';}
+"<>"                  {return '<>';}
+">"|"<"|"<="|">="     {return 'LTGT';}
+"contains"|"CONTAINS" {return 'CONTAINS';}
+"like"|"LIKE"         {return 'LIKE';}
+[0-9]+                {return 'INTEGER';}
+\"[^\"]*\"            {return 'STRING';}
+[A-Za-z]+             {return 'VAR';}
+"("                   {return 'OPEN';}
+")"                   {return 'CLOSE';}
+<<EOF>>               {return 'EOF';}
+
+/lex
+
+/* operator associations and precedence */
+
+%left '=' '<>'
+%left 'LTGT'
+%left 'AND' 'OR'
+%left 'NOT'
+%left 'CONTAINS' 'LIKE'
+
+%start expressions
+
+%% /* language grammar */
+
+expressions
+    : e EOF
+        {return $1;}
+    ;
+e
+    : 'NOT' e
+        {$$ = "!" + $2;}
+    | 'OPEN' e 'CLOSE'
+        {$$ = "(" + $2 + ")";}
+    | e 'AND' e
+        {$$ = $1 + " && " + $3;}
+    | e 'OR' e
+        {$$ = $1 + " || " + $3;}
+    | value '=' value
+        {$$ = $1 + "==" + $3;}
+    | value '<>' value
+        {$$ = $1 + "!=" + $3;}
+    | value 'LTGT' value
+        {$$ = $1 + $2 + $3}
+    | value 'CONTAINS' value
+        {$$ = "(" + $1 + "&&" + $1 + ".indexOf(" + $3 + ")" + " >= 0)"; }
+    | value 'LIKE' value
+        {$$ = "_helpers['match'](" + $1 + "," + $3 + ")";}
+    | value
+        {$$ = $1;}
+    ;
+value
+    : INTEGER
+        {$$ = Number(yytext);}
+    | STRING
+        {$$ = yytext;}
+    | VAR
+        {$$ = "_env['" + yytext + "']";}
+    ;