diff --git a/lib/parser.js b/lib/parser.js
index fb2ca94..26a0dce 100644
--- a/lib/parser.js
+++ b/lib/parser.js
@@ -913,38 +913,24 @@ module.exports = (function(){
           pos = r2;
         }
         if (r0 !== null) {
-          reportedPos = r1;
-          r0 = (function(parts) {
-              return "{" + parts.join("") + "}";
-            })(r4);
-        }
-        if (r0 === null) {
-          pos = r1;
+          r0 = input.substring(pos, r1);
         }
         return r0;
       }
       
       function parse_nonBraceCharacters() {
-        var r0, r1, r2;
+        var r0, r1;
         
-        r1 = pos;
-        r2 = parse_nonBraceCharacter();
-        if (r2 !== null) {
+        r1 = parse_nonBraceCharacter();
+        if (r1 !== null) {
           r0 = [];
-          while (r2 !== null) {
-            r0.push(r2);
-            r2 = parse_nonBraceCharacter();
+          while (r1 !== null) {
+            r0.push(r1);
+            r1 = parse_nonBraceCharacter();
           }
         } else {
           r0 = null;
         }
-        if (r0 !== null) {
-          reportedPos = r1;
-          r0 = (function(chars) { return chars.join(""); })(r0);
-        }
-        if (r0 === null) {
-          pos = r1;
-        }
         return r0;
       }
       
@@ -1432,51 +1418,53 @@ module.exports = (function(){
       }
       
       function parse_identifier() {
-        var r0, r1, r2, r3, r4, r5;
+        var r0, r1, r2, r3, r4, r5, r6, r7, r8;
         
         reportFailures++;
         r1 = pos;
         r2 = pos;
-        r3 = parse_letter();
-        if (r3 === null) {
+        r4 = pos;
+        r5 = pos;
+        r6 = parse_letter();
+        if (r6 === null) {
           if (input.charCodeAt(pos) === 95) {
-            r3 = "_";
+            r6 = "_";
             pos++;
           } else {
-            r3 = null;
+            r6 = null;
             if (reportFailures === 0) {
               matchFailed("\"_\"");
             }
           }
         }
-        if (r3 !== null) {
-          r4 = [];
-          r5 = parse_letter();
-          if (r5 === null) {
-            r5 = parse_digit();
-            if (r5 === null) {
+        if (r6 !== null) {
+          r7 = [];
+          r8 = parse_letter();
+          if (r8 === null) {
+            r8 = parse_digit();
+            if (r8 === null) {
               if (input.charCodeAt(pos) === 95) {
-                r5 = "_";
+                r8 = "_";
                 pos++;
               } else {
-                r5 = null;
+                r8 = null;
                 if (reportFailures === 0) {
                   matchFailed("\"_\"");
                 }
               }
             }
           }
-          while (r5 !== null) {
-            r4.push(r5);
-            r5 = parse_letter();
-            if (r5 === null) {
-              r5 = parse_digit();
-              if (r5 === null) {
+          while (r8 !== null) {
+            r7.push(r8);
+            r8 = parse_letter();
+            if (r8 === null) {
+              r8 = parse_digit();
+              if (r8 === null) {
                 if (input.charCodeAt(pos) === 95) {
-                  r5 = "_";
+                  r8 = "_";
                   pos++;
                 } else {
-                  r5 = null;
+                  r8 = null;
                   if (reportFailures === 0) {
                     matchFailed("\"_\"");
                   }
@@ -1484,14 +1472,23 @@ module.exports = (function(){
               }
             }
           }
+          if (r7 !== null) {
+            r3 = [r6, r7];
+          } else {
+            r3 = null;
+            pos = r5;
+          }
+        } else {
+          r3 = null;
+          pos = r5;
+        }
+        if (r3 !== null) {
+          r3 = input.substring(pos, r4);
+        }
+        if (r3 !== null) {
+          r4 = parse___();
           if (r4 !== null) {
-            r5 = parse___();
-            if (r5 !== null) {
-              r0 = [r3, r4, r5];
-            } else {
-              r0 = null;
-              pos = r2;
-            }
+            r0 = [r3, r4];
           } else {
             r0 = null;
             pos = r2;
@@ -1502,9 +1499,7 @@ module.exports = (function(){
         }
         if (r0 !== null) {
           reportedPos = r1;
-          r0 = (function(head, tail) {
-              return head + tail.join("");
-            })(r3, r4);
+          r0 = (function(chars) { return chars; })(r3);
         }
         if (r0 === null) {
           pos = r1;
@@ -2317,7 +2312,7 @@ module.exports = (function(){
       }
       
       function parse_hexEscapeSequence() {
-        var r0, r1, r2, r3, r4, r5;
+        var r0, r1, r2, r3, r4, r5, r6, r7, r8;
         
         r1 = pos;
         r2 = pos;
@@ -2331,15 +2326,26 @@ module.exports = (function(){
           }
         }
         if (r3 !== null) {
-          r4 = parse_hexDigit();
-          if (r4 !== null) {
-            r5 = parse_hexDigit();
-            if (r5 !== null) {
-              r0 = [r3, r4, r5];
+          r5 = pos;
+          r6 = pos;
+          r7 = parse_hexDigit();
+          if (r7 !== null) {
+            r8 = parse_hexDigit();
+            if (r8 !== null) {
+              r4 = [r7, r8];
             } else {
-              r0 = null;
-              pos = r2;
+              r4 = null;
+              pos = r6;
             }
+          } else {
+            r4 = null;
+            pos = r6;
+          }
+          if (r4 !== null) {
+            r4 = input.substring(pos, r5);
+          }
+          if (r4 !== null) {
+            r0 = [r3, r4];
           } else {
             r0 = null;
             pos = r2;
@@ -2350,9 +2356,9 @@ module.exports = (function(){
         }
         if (r0 !== null) {
           reportedPos = r1;
-          r0 = (function(h1, h2) {
-              return String.fromCharCode(parseInt(h1 + h2, 16));
-            })(r4, r5);
+          r0 = (function(digits) {
+              return String.fromCharCode(parseInt(digits, 16));
+            })(r4);
         }
         if (r0 === null) {
           pos = r1;
@@ -2361,7 +2367,7 @@ module.exports = (function(){
       }
       
       function parse_unicodeEscapeSequence() {
-        var r0, r1, r2, r3, r4, r5, r6, r7;
+        var r0, r1, r2, r3, r4, r5, r6, r7, r8, r9, r10;
         
         r1 = pos;
         r2 = pos;
@@ -2375,27 +2381,38 @@ module.exports = (function(){
           }
         }
         if (r3 !== null) {
-          r4 = parse_hexDigit();
-          if (r4 !== null) {
-            r5 = parse_hexDigit();
-            if (r5 !== null) {
-              r6 = parse_hexDigit();
-              if (r6 !== null) {
-                r7 = parse_hexDigit();
-                if (r7 !== null) {
-                  r0 = [r3, r4, r5, r6, r7];
+          r5 = pos;
+          r6 = pos;
+          r7 = parse_hexDigit();
+          if (r7 !== null) {
+            r8 = parse_hexDigit();
+            if (r8 !== null) {
+              r9 = parse_hexDigit();
+              if (r9 !== null) {
+                r10 = parse_hexDigit();
+                if (r10 !== null) {
+                  r4 = [r7, r8, r9, r10];
                 } else {
-                  r0 = null;
-                  pos = r2;
+                  r4 = null;
+                  pos = r6;
                 }
               } else {
-                r0 = null;
-                pos = r2;
+                r4 = null;
+                pos = r6;
               }
             } else {
-              r0 = null;
-              pos = r2;
+              r4 = null;
+              pos = r6;
             }
+          } else {
+            r4 = null;
+            pos = r6;
+          }
+          if (r4 !== null) {
+            r4 = input.substring(pos, r5);
+          }
+          if (r4 !== null) {
+            r0 = [r3, r4];
           } else {
             r0 = null;
             pos = r2;
@@ -2406,9 +2423,9 @@ module.exports = (function(){
         }
         if (r0 !== null) {
           reportedPos = r1;
-          r0 = (function(h1, h2, h3, h4) {
-              return String.fromCharCode(parseInt(h1 + h2 + h3 + h4, 16));
-            })(r4, r5, r6, r7);
+          r0 = (function(digits) {
+              return String.fromCharCode(parseInt(digits, 16));
+            })(r4);
         }
         if (r0 === null) {
           pos = r1;
diff --git a/src/parser.pegjs b/src/parser.pegjs
index 91bac72..39ed65a 100644
--- a/src/parser.pegjs
+++ b/src/parser.pegjs
@@ -159,12 +159,10 @@ action "action"
   = braced:braced __ { return braced.substr(1, braced.length - 2); }
 
 braced
-  = "{" parts:(braced / nonBraceCharacters)* "}" {
-      return "{" + parts.join("") + "}";
-    }
+  = $("{" (braced / nonBraceCharacters)* "}")
 
 nonBraceCharacters
-  = chars:nonBraceCharacter+ { return chars.join(""); }
+  = nonBraceCharacter+
 
 nonBraceCharacter
   = [^{}]
@@ -202,9 +200,7 @@ dot       = "." __ { return "."; }
  * purpose in the grammar.
  */
 identifier "identifier"
-  = head:(letter / "_") tail:(letter / digit / "_")* __ {
-      return head + tail.join("");
-    }
+  = chars:$((letter / "_") (letter / digit / "_")*) __ { return chars; }
 
 /*
  * Modeled after ECMA-262, 5th ed., 7.8.4. (syntax & semantics, rules only
@@ -319,13 +315,13 @@ zeroEscapeSequence
   = "\\0" !digit { return "\x00"; }
 
 hexEscapeSequence
-  = "\\x" h1:hexDigit h2:hexDigit {
-      return String.fromCharCode(parseInt(h1 + h2, 16));
+  = "\\x" digits:$(hexDigit hexDigit) {
+      return String.fromCharCode(parseInt(digits, 16));
     }
 
 unicodeEscapeSequence
-  = "\\u" h1:hexDigit h2:hexDigit h3:hexDigit h4:hexDigit {
-      return String.fromCharCode(parseInt(h1 + h2 + h3 + h4, 16));
+  = "\\u" digits:$(hexDigit hexDigit hexDigit hexDigit) {
+      return String.fromCharCode(parseInt(digits, 16));
     }
 
 eolEscapeSequence