PEG based wikitext parser

wikipeg.js

wikitext = (function(){
  /* Generated by PEG.js 0.6.1 (http://pegjs.majda.cz/). */
  
  var result = {
    /*
     * Parses the input with a generated parser. If the parsing is successfull,
     * returns a value explicitly or implicitly specified by the grammar from
     * which the parser was generated (see |PEG.buildParser|). If the parsing is
     * unsuccessful, throws |PEG.parser.SyntaxError| describing the error.
     */
    parse: function(input, startRule) {
      var parseFunctions = {
        "eol": parse_eol,
        "heading": parse_heading,
        "inline": parse_inline,
        "line": parse_line,
        "link": parse_link,
        "list": parse_list,
        "olist": parse_olist,
        "space": parse_space,
        "start": parse_start,
        "text": parse_text,
        "ulist": parse_ulist,
        "word": parse_word
      };
      
      if (startRule !== undefined) {
        if (parseFunctions[startRule] === undefined) {
          throw new Error("Invalid rule name: " + quote(startRule) + ".");
        }
      } else {
        startRule = "start";
      }
      
      var pos = 0;
      var reportMatchFailures = true;
      var rightmostMatchFailuresPos = 0;
      var rightmostMatchFailuresExpected = [];
      var cache = {};
      
      function padLeft(input, padding, length) {
        var result = input;
        
        var padLength = length - input.length;
        for (var i = 0; i < padLength; i++) {
          result = padding + result;
        }
        
        return result;
      }
      
      function escape(ch) {
        var charCode = ch.charCodeAt(0);
        
        if (charCode <= 0xFF) {
          var escapeChar = 'x';
          var length = 2;
        } else {
          var escapeChar = 'u';
          var length = 4;
        }
        
        return '\\' + escapeChar + padLeft(charCode.toString(16).toUpperCase(), '0', length);
      }
      
      function quote(s) {
        /*
         * ECMA-262, 5th ed., 7.8.4: All characters may appear literally in a
         * string literal except for the closing quote character, backslash,
         * carriage return, line separator, paragraph separator, and line feed.
         * Any character may appear in the form of an escape sequence.
         */
        return '"' + s
          .replace(/\\/g, '\\\\')            // backslash
          .replace(/"/g, '\\"')              // closing quote character
          .replace(/\r/g, '\\r')             // carriage return
          .replace(/\n/g, '\\n')             // line feed
          .replace(/[\x80-\uFFFF]/g, escape) // non-ASCII characters
          + '"';
      }
      
      function matchFailed(failure) {
        if (pos < rightmostMatchFailuresPos) {
          return;
        }
        
        if (pos > rightmostMatchFailuresPos) {
          rightmostMatchFailuresPos = pos;
          rightmostMatchFailuresExpected = [];
        }
        
        rightmostMatchFailuresExpected.push(failure);
      }
      
      function parse_start() {
        var cacheKey = 'start@' + pos;
        var cachedResult = cache[cacheKey];
        if (cachedResult) {
          pos = cachedResult.nextPos;
          return cachedResult.result;
        }
        
        
        var result1 = parse_line();
        if (result1 !== null) {
          var result0 = [];
          while (result1 !== null) {
            result0.push(result1);
            var result1 = parse_line();
          }
        } else {
          var result0 = null;
        }
        
        
        
        cache[cacheKey] = {
          nextPos: pos,
          result:  result0
        };
        return result0;
      }
      
      function parse_line() {
        var cacheKey = 'line@' + pos;
        var cachedResult = cache[cacheKey];
        if (cachedResult) {
          pos = cachedResult.nextPos;
          return cachedResult.result;
        }
        
        
        var result4 = parse_heading();
        if (result4 !== null) {
          var result0 = result4;
        } else {
          var result3 = parse_list();
          if (result3 !== null) {
            var result0 = result3;
          } else {
            var result2 = parse_text();
            if (result2 !== null) {
              var result0 = result2;
            } else {
              var result1 = parse_eol();
              if (result1 !== null) {
                var result0 = result1;
              } else {
                var result0 = null;;
              };
            };
          };
        }
        
        
        
        cache[cacheKey] = {
          nextPos: pos,
          result:  result0
        };
        return result0;
      }
      
      function parse_heading() {
        var cacheKey = 'heading@' + pos;
        var cachedResult = cache[cacheKey];
        if (cachedResult) {
          pos = cachedResult.nextPos;
          return cachedResult.result;
        }
        
        
        var savedPos0 = pos;
        if (input.substr(pos, 1) === "!") {
          var result2 = "!";
          pos += 1;
        } else {
          var result2 = null;
          if (reportMatchFailures) {
            matchFailed("\"!\"");
          }
        }
        if (result2 !== null) {
          var result3 = parse_text();
          if (result3 !== null) {
            var result1 = [result2, result3];
          } else {
            var result1 = null;
            pos = savedPos0;
          }
        } else {
          var result1 = null;
          pos = savedPos0;
        }
        var result0 = result1 !== null
          ? (function(bang, text) { return {type: "HEADING", value: text}; })(result1[0], result1[1])
          : null;
        
        
        
        cache[cacheKey] = {
          nextPos: pos,
          result:  result0
        };
        return result0;
      }
      
      function parse_text() {
        var cacheKey = 'text@' + pos;
        var cachedResult = cache[cacheKey];
        if (cachedResult) {
          pos = cachedResult.nextPos;
          return cachedResult.result;
        }
        
        
        var savedPos0 = pos;
        var result4 = parse_word();
        if (result4 !== null) {
          var result6 = parse_space();
          var result5 = result6 !== null ? result6 : '';
          if (result5 !== null) {
            var result3 = [result4, result5];
          } else {
            var result3 = null;
            pos = savedPos0;
          }
        } else {
          var result3 = null;
          pos = savedPos0;
        }
        var result2 = result3 !== null
          ? (function(word, space) {
          	return (typeof word === 'string') ? word + space :
          		((space) ? [word, space] : word);
          	})(result3[0], result3[1])
          : null;
        if (result2 !== null) {
          var result1 = [];
          while (result2 !== null) {
            result1.push(result2);
            var savedPos0 = pos;
            var result4 = parse_word();
            if (result4 !== null) {
              var result6 = parse_space();
              var result5 = result6 !== null ? result6 : '';
              if (result5 !== null) {
                var result3 = [result4, result5];
              } else {
                var result3 = null;
                pos = savedPos0;
              }
            } else {
              var result3 = null;
              pos = savedPos0;
            }
            var result2 = result3 !== null
              ? (function(word, space) {
              	return (typeof word === 'string') ? word + space :
              		((space) ? [word, space] : word);
              	})(result3[0], result3[1])
              : null;
          }
        } else {
          var result1 = null;
        }
        var result0 = result1 !== null
          ? (function(text) {
          		var result = (function() {
          			var res = [], bufStr = '';
          			for (var i = 0; i < text.length; i++) {
          				if (typeof text[i] !== 'string') {
          					if (bufStr) {
          						res.push(bufStr);
          						bufStr = '';
          					}
          					res.push(text[i]);
          				} else {
          					bufStr += text[i];
          				}
          			}
          			if (bufStr) {
          				res.push(bufStr);
          			}
          			if (res.length === 1 && typeof res[0] === 'string') {
          				return { type: 'TEXT', value: res[0] }
          			} else if (res.length === 1) {
          				return res[0];
          			} else {
          				return res;
          			}
          		}());
          		return result;
          	})(result1)
          : null;
        
        
        
        cache[cacheKey] = {
          nextPos: pos,
          result:  result0
        };
        return result0;
      }
      
      function parse_eol() {
        var cacheKey = 'eol@' + pos;
        var cachedResult = cache[cacheKey];
        if (cachedResult) {
          pos = cachedResult.nextPos;
          return cachedResult.result;
        }
        
        
        if (input.substr(pos, 1) === "\n") {
          var result1 = "\n";
          pos += 1;
        } else {
          var result1 = null;
          if (reportMatchFailures) {
            matchFailed("\"\\n\"");
          }
        }
        var result0 = result1 !== null
          ? (function(end) { return "EOL"; })(result1)
          : null;
        
        
        
        cache[cacheKey] = {
          nextPos: pos,
          result:  result0
        };
        return result0;
      }
      
      function parse_space() {
        var cacheKey = 'space@' + pos;
        var cachedResult = cache[cacheKey];
        if (cachedResult) {
          pos = cachedResult.nextPos;
          return cachedResult.result;
        }
        
        
        if (input.substr(pos).match(/^[ 	]/) !== null) {
          var result2 = input.charAt(pos);
          pos++;
        } else {
          var result2 = null;
          if (reportMatchFailures) {
            matchFailed("[ 	]");
          }
        }
        if (result2 !== null) {
          var result1 = [];
          while (result2 !== null) {
            result1.push(result2);
            if (input.substr(pos).match(/^[ 	]/) !== null) {
              var result2 = input.charAt(pos);
              pos++;
            } else {
              var result2 = null;
              if (reportMatchFailures) {
                matchFailed("[ 	]");
              }
            }
          }
        } else {
          var result1 = null;
        }
        var result0 = result1 !== null
          ? (function(ws) { return ws.join(''); })(result1)
          : null;
        
        
        
        cache[cacheKey] = {
          nextPos: pos,
          result:  result0
        };
        return result0;
      }
      
      function parse_word() {
        var cacheKey = 'word@' + pos;
        var cachedResult = cache[cacheKey];
        if (cachedResult) {
          pos = cachedResult.nextPos;
          return cachedResult.result;
        }
        
        
        var result5 = parse_inline();
        var result4 = result5 !== null
          ? (function(inline) { return inline; })(result5)
          : null;
        if (result4 !== null) {
          var result0 = result4;
        } else {
          if (input.substr(pos).match(/^[^ 	\n]/) !== null) {
            var result3 = input.charAt(pos);
            pos++;
          } else {
            var result3 = null;
            if (reportMatchFailures) {
              matchFailed("[^ 	\\n]");
            }
          }
          if (result3 !== null) {
            var result2 = [];
            while (result3 !== null) {
              result2.push(result3);
              if (input.substr(pos).match(/^[^ 	\n]/) !== null) {
                var result3 = input.charAt(pos);
                pos++;
              } else {
                var result3 = null;
                if (reportMatchFailures) {
                  matchFailed("[^ 	\\n]");
                }
              }
            }
          } else {
            var result2 = null;
          }
          var result1 = result2 !== null
            ? (function(text) { return text.join(''); })(result2)
            : null;
          if (result1 !== null) {
            var result0 = result1;
          } else {
            var result0 = null;;
          };
        }
        
        
        
        cache[cacheKey] = {
          nextPos: pos,
          result:  result0
        };
        return result0;
      }
      
      function parse_inline() {
        var cacheKey = 'inline@' + pos;
        var cachedResult = cache[cacheKey];
        if (cachedResult) {
          pos = cachedResult.nextPos;
          return cachedResult.result;
        }
        
        
        var savedPos0 = pos;
        if (input.substr(pos, 2) === "<<") {
          var result5 = "<<";
          pos += 2;
        } else {
          var result5 = null;
          if (reportMatchFailures) {
            matchFailed("\"<<\"");
          }
        }
        if (result5 !== null) {
          if (input.substr(pos).match(/^[^>>]/) !== null) {
            var result8 = input.charAt(pos);
            pos++;
          } else {
            var result8 = null;
            if (reportMatchFailures) {
              matchFailed("[^>>]");
            }
          }
          if (result8 !== null) {
            var result6 = [];
            while (result8 !== null) {
              result6.push(result8);
              if (input.substr(pos).match(/^[^>>]/) !== null) {
                var result8 = input.charAt(pos);
                pos++;
              } else {
                var result8 = null;
                if (reportMatchFailures) {
                  matchFailed("[^>>]");
                }
              }
            }
          } else {
            var result6 = null;
          }
          if (result6 !== null) {
            if (input.substr(pos, 2) === ">>") {
              var result7 = ">>";
              pos += 2;
            } else {
              var result7 = null;
              if (reportMatchFailures) {
                matchFailed("\">>\"");
              }
            }
            if (result7 !== null) {
              var result4 = [result5, result6, result7];
            } else {
              var result4 = null;
              pos = savedPos0;
            }
          } else {
            var result4 = null;
            pos = savedPos0;
          }
        } else {
          var result4 = null;
          pos = savedPos0;
        }
        var result3 = result4 !== null
          ? (function(text) { return {type: 'TRANSCLUDE', value: text.join('')}; })(result4[1])
          : null;
        if (result3 !== null) {
          var result0 = result3;
        } else {
          var result2 = parse_link();
          var result1 = result2 !== null
            ? (function(link) { return link; })(result2)
            : null;
          if (result1 !== null) {
            var result0 = result1;
          } else {
            var result0 = null;;
          };
        }
        
        
        
        cache[cacheKey] = {
          nextPos: pos,
          result:  result0
        };
        return result0;
      }
      
      function parse_link() {
        var cacheKey = 'link@' + pos;
        var cachedResult = cache[cacheKey];
        if (cachedResult) {
          pos = cachedResult.nextPos;
          return cachedResult.result;
        }
        
        
        var savedPos2 = pos;
        if (input.substr(pos, 2) === "[[") {
          var result21 = "[[";
          pos += 2;
        } else {
          var result21 = null;
          if (reportMatchFailures) {
            matchFailed("\"[[\"");
          }
        }
        if (result21 !== null) {
          if (input.substr(pos).match(/^[^\]\]|]/) !== null) {
            var result24 = input.charAt(pos);
            pos++;
          } else {
            var result24 = null;
            if (reportMatchFailures) {
              matchFailed("[^\\]\\]|]");
            }
          }
          if (result24 !== null) {
            var result22 = [];
            while (result24 !== null) {
              result22.push(result24);
              if (input.substr(pos).match(/^[^\]\]|]/) !== null) {
                var result24 = input.charAt(pos);
                pos++;
              } else {
                var result24 = null;
                if (reportMatchFailures) {
                  matchFailed("[^\\]\\]|]");
                }
              }
            }
          } else {
            var result22 = null;
          }
          if (result22 !== null) {
            if (input.substr(pos, 2) === "]]") {
              var result23 = "]]";
              pos += 2;
            } else {
              var result23 = null;
              if (reportMatchFailures) {
                matchFailed("\"]]\"");
              }
            }
            if (result23 !== null) {
              var result20 = [result21, result22, result23];
            } else {
              var result20 = null;
              pos = savedPos2;
            }
          } else {
            var result20 = null;
            pos = savedPos2;
          }
        } else {
          var result20 = null;
          pos = savedPos2;
        }
        var result19 = result20 !== null
          ? (function(text) { return {type: 'LINK', value: text.join('')}; })(result20[1])
          : null;
        if (result19 !== null) {
          var result0 = result19;
        } else {
          var savedPos1 = pos;
          if (input.substr(pos, 2) === "[[") {
            var result12 = "[[";
            pos += 2;
          } else {
            var result12 = null;
            if (reportMatchFailures) {
              matchFailed("\"[[\"");
            }
          }
          if (result12 !== null) {
            if (input.substr(pos).match(/^[^|]/) !== null) {
              var result18 = input.charAt(pos);
              pos++;
            } else {
              var result18 = null;
              if (reportMatchFailures) {
                matchFailed("[^|]");
              }
            }
            if (result18 !== null) {
              var result13 = [];
              while (result18 !== null) {
                result13.push(result18);
                if (input.substr(pos).match(/^[^|]/) !== null) {
                  var result18 = input.charAt(pos);
                  pos++;
                } else {
                  var result18 = null;
                  if (reportMatchFailures) {
                    matchFailed("[^|]");
                  }
                }
              }
            } else {
              var result13 = null;
            }
            if (result13 !== null) {
              if (input.substr(pos, 1) === "|") {
                var result14 = "|";
                pos += 1;
              } else {
                var result14 = null;
                if (reportMatchFailures) {
                  matchFailed("\"|\"");
                }
              }
              if (result14 !== null) {
                if (input.substr(pos).match(/^[^\]\]]/) !== null) {
                  var result17 = input.charAt(pos);
                  pos++;
                } else {
                  var result17 = null;
                  if (reportMatchFailures) {
                    matchFailed("[^\\]\\]]");
                  }
                }
                if (result17 !== null) {
                  var result15 = [];
                  while (result17 !== null) {
                    result15.push(result17);
                    if (input.substr(pos).match(/^[^\]\]]/) !== null) {
                      var result17 = input.charAt(pos);
                      pos++;
                    } else {
                      var result17 = null;
                      if (reportMatchFailures) {
                        matchFailed("[^\\]\\]]");
                      }
                    }
                  }
                } else {
                  var result15 = null;
                }
                if (result15 !== null) {
                  if (input.substr(pos, 2) === "]]") {
                    var result16 = "]]";
                    pos += 2;
                  } else {
                    var result16 = null;
                    if (reportMatchFailures) {
                      matchFailed("\"]]\"");
                    }
                  }
                  if (result16 !== null) {
                    var result11 = [result12, result13, result14, result15, result16];
                  } else {
                    var result11 = null;
                    pos = savedPos1;
                  }
                } else {
                  var result11 = null;
                  pos = savedPos1;
                }
              } else {
                var result11 = null;
                pos = savedPos1;
              }
            } else {
              var result11 = null;
              pos = savedPos1;
            }
          } else {
            var result11 = null;
            pos = savedPos1;
          }
          var result10 = result11 !== null
            ? (function(name, link) { return {type: 'LINK', value: {TITLE: name.join(''), LINK: link.join('')}}; })(result11[1], result11[3])
            : null;
          if (result10 !== null) {
            var result0 = result10;
          } else {
            var savedPos0 = pos;
            if (input.substr(pos).match(/^[A-Z]/) !== null) {
              var result3 = input.charAt(pos);
              pos++;
            } else {
              var result3 = null;
              if (reportMatchFailures) {
                matchFailed("[A-Z]");
              }
            }
            if (result3 !== null) {
              var result4 = [];
              if (input.substr(pos).match(/^[a-z0-9]/) !== null) {
                var result9 = input.charAt(pos);
                pos++;
              } else {
                var result9 = null;
                if (reportMatchFailures) {
                  matchFailed("[a-z0-9]");
                }
              }
              while (result9 !== null) {
                result4.push(result9);
                if (input.substr(pos).match(/^[a-z0-9]/) !== null) {
                  var result9 = input.charAt(pos);
                  pos++;
                } else {
                  var result9 = null;
                  if (reportMatchFailures) {
                    matchFailed("[a-z0-9]");
                  }
                }
              }
              if (result4 !== null) {
                if (input.substr(pos).match(/^[A-Z]/) !== null) {
                  var result8 = input.charAt(pos);
                  pos++;
                } else {
                  var result8 = null;
                  if (reportMatchFailures) {
                    matchFailed("[A-Z]");
                  }
                }
                if (result8 !== null) {
                  var result5 = [];
                  while (result8 !== null) {
                    result5.push(result8);
                    if (input.substr(pos).match(/^[A-Z]/) !== null) {
                      var result8 = input.charAt(pos);
                      pos++;
                    } else {
                      var result8 = null;
                      if (reportMatchFailures) {
                        matchFailed("[A-Z]");
                      }
                    }
                  }
                } else {
                  var result5 = null;
                }
                if (result5 !== null) {
                  if (input.substr(pos).match(/^[0-9a-zA-Z]/) !== null) {
                    var result7 = input.charAt(pos);
                    pos++;
                  } else {
                    var result7 = null;
                    if (reportMatchFailures) {
                      matchFailed("[0-9a-zA-Z]");
                    }
                  }
                  if (result7 !== null) {
                    var result6 = [];
                    while (result7 !== null) {
                      result6.push(result7);
                      if (input.substr(pos).match(/^[0-9a-zA-Z]/) !== null) {
                        var result7 = input.charAt(pos);
                        pos++;
                      } else {
                        var result7 = null;
                        if (reportMatchFailures) {
                          matchFailed("[0-9a-zA-Z]");
                        }
                      }
                    }
                  } else {
                    var result6 = null;
                  }
                  if (result6 !== null) {
                    var result2 = [result3, result4, result5, result6];
                  } else {
                    var result2 = null;
                    pos = savedPos0;
                  }
                } else {
                  var result2 = null;
                  pos = savedPos0;
                }
              } else {
                var result2 = null;
                pos = savedPos0;
              }
            } else {
              var result2 = null;
              pos = savedPos0;
            }
            var result1 = result2 !== null
              ? (function(firstCap, firstText, secondCap, lastText) { return {type: 'WIKILINK', value: firstCap + firstText.join('') + secondCap.join('') + lastText.join('')}; })(result2[0], result2[1], result2[2], result2[3])
              : null;
            if (result1 !== null) {
              var result0 = result1;
            } else {
              var result0 = null;;
            };
          };
        }
        
        
        
        cache[cacheKey] = {
          nextPos: pos,
          result:  result0
        };
        return result0;
      }
      
      function parse_list() {
        var cacheKey = 'list@' + pos;
        var cachedResult = cache[cacheKey];
        if (cachedResult) {
          pos = cachedResult.nextPos;
          return cachedResult.result;
        }
        
        
        var result6 = parse_ulist();
        if (result6 !== null) {
          var result5 = [];
          while (result6 !== null) {
            result5.push(result6);
            var result6 = parse_ulist();
          }
        } else {
          var result5 = null;
        }
        var result4 = result5 !== null
          ? (function(list) { return {type: 'ULIST', value: list}; })(result5)
          : null;
        if (result4 !== null) {
          var result0 = result4;
        } else {
          var result3 = parse_olist();
          if (result3 !== null) {
            var result2 = [];
            while (result3 !== null) {
              result2.push(result3);
              var result3 = parse_olist();
            }
          } else {
            var result2 = null;
          }
          var result1 = result2 !== null
            ? (function(list) {return {type: 'OLIST', value: list}; })(result2)
            : null;
          if (result1 !== null) {
            var result0 = result1;
          } else {
            var result0 = null;;
          };
        }
        
        
        
        cache[cacheKey] = {
          nextPos: pos,
          result:  result0
        };
        return result0;
      }
      
      function parse_ulist() {
        var cacheKey = 'ulist@' + pos;
        var cachedResult = cache[cacheKey];
        if (cachedResult) {
          pos = cachedResult.nextPos;
          return cachedResult.result;
        }
        
        
        var savedPos0 = pos;
        if (input.substr(pos, 1) === "*") {
          var result2 = "*";
          pos += 1;
        } else {
          var result2 = null;
          if (reportMatchFailures) {
            matchFailed("\"*\"");
          }
        }
        if (result2 !== null) {
          var result8 = parse_space();
          var result3 = result8 !== null ? result8 : '';
          if (result3 !== null) {
            var result7 = parse_text();
            var result4 = result7 !== null ? result7 : '';
            if (result4 !== null) {
              var result6 = parse_eol();
              var result5 = result6 !== null ? result6 : '';
              if (result5 !== null) {
                var result1 = [result2, result3, result4, result5];
              } else {
                var result1 = null;
                pos = savedPos0;
              }
            } else {
              var result1 = null;
              pos = savedPos0;
            }
          } else {
            var result1 = null;
            pos = savedPos0;
          }
        } else {
          var result1 = null;
          pos = savedPos0;
        }
        var result0 = result1 !== null
          ? (function(text) { return {type: 'ULI', value: text}; })(result1[2])
          : null;
        
        
        
        cache[cacheKey] = {
          nextPos: pos,
          result:  result0
        };
        return result0;
      }
      
      function parse_olist() {
        var cacheKey = 'olist@' + pos;
        var cachedResult = cache[cacheKey];
        if (cachedResult) {
          pos = cachedResult.nextPos;
          return cachedResult.result;
        }
        
        
        var savedPos0 = pos;
        if (input.substr(pos, 1) === "#") {
          var result2 = "#";
          pos += 1;
        } else {
          var result2 = null;
          if (reportMatchFailures) {
            matchFailed("\"#\"");
          }
        }
        if (result2 !== null) {
          var result8 = parse_space();
          var result3 = result8 !== null ? result8 : '';
          if (result3 !== null) {
            var result7 = parse_text();
            var result4 = result7 !== null ? result7 : '';
            if (result4 !== null) {
              var result6 = parse_eol();
              var result5 = result6 !== null ? result6 : '';
              if (result5 !== null) {
                var result1 = [result2, result3, result4, result5];
              } else {
                var result1 = null;
                pos = savedPos0;
              }
            } else {
              var result1 = null;
              pos = savedPos0;
            }
          } else {
            var result1 = null;
            pos = savedPos0;
          }
        } else {
          var result1 = null;
          pos = savedPos0;
        }
        var result0 = result1 !== null
          ? (function(text) { return {type: 'OLI', value: text}; })(result1[2])
          : null;
        
        
        
        cache[cacheKey] = {
          nextPos: pos,
          result:  result0
        };
        return result0;
      }
      
      function buildErrorMessage() {
        function buildExpected(failuresExpected) {
          failuresExpected.sort();
          
          var lastFailure = null;
          var failuresExpectedUnique = [];
          for (var i = 0; i < failuresExpected.length; i++) {
            if (failuresExpected[i] !== lastFailure) {
              failuresExpectedUnique.push(failuresExpected[i]);
              lastFailure = failuresExpected[i];
            }
          }
          
          switch (failuresExpectedUnique.length) {
            case 0:
              return 'end of input';
            case 1:
              return failuresExpectedUnique[0];
            default:
              return failuresExpectedUnique.slice(0, failuresExpectedUnique.length - 1).join(', ')
                + ' or '
                + failuresExpectedUnique[failuresExpectedUnique.length - 1];
          }
        }
        
        var expected = buildExpected(rightmostMatchFailuresExpected);
        var actualPos = Math.max(pos, rightmostMatchFailuresPos);
        var actual = actualPos < input.length
          ? quote(input.charAt(actualPos))
          : 'end of input';
        
        return 'Expected ' + expected + ' but ' + actual + ' found.';
      }
      
      function computeErrorPosition() {
        /*
         * The first idea was to use |String.split| to break the input up to the
         * error position along newlines and derive the line and column from
         * there. However IE's |split| implementation is so broken that it was
         * enough to prevent it.
         */
        
        var line = 1;
        var column = 1;
        var seenCR = false;
        
        for (var i = 0; i <  rightmostMatchFailuresPos; i++) {
          var ch = input.charAt(i);
          if (ch === '\n') {
            if (!seenCR) { line++; }
            column = 1;
            seenCR = false;
          } else if (ch === '\r' | ch === '\u2028' || ch === '\u2029') {
            line++;
            column = 1;
            seenCR = true;
          } else {
            column++;
            seenCR = false;
          }
        }
        
        return { line: line, column: column };
      }
      
      
      
      var result = parseFunctions[startRule]();
      
      /*
       * The parser is now in one of the following three states:
       *
       * 1. The parser successfully parsed the whole input.
       *
       *    - |result !== null|
       *    - |pos === input.length|
       *    - |rightmostMatchFailuresExpected| may or may not contain something
       *
       * 2. The parser successfully parsed only a part of the input.
       *
       *    - |result !== null|
       *    - |pos < input.length|
       *    - |rightmostMatchFailuresExpected| may or may not contain something
       *
       * 3. The parser did not successfully parse any part of the input.
       *
       *   - |result === null|
       *   - |pos === 0|
       *   - |rightmostMatchFailuresExpected| contains at least one failure
       *
       * All code following this comment (including called functions) must
       * handle these states.
       */
      if (result === null || pos !== input.length) {
        var errorPosition = computeErrorPosition();
        throw new this.SyntaxError(
          buildErrorMessage(),
          errorPosition.line,
          errorPosition.column
        );
      }
      
      return result;
    },
    
    /* Returns the parser source code. */
    toSource: function() { return this._source; }
  };
  
  /* Thrown when a parser encounters a syntax error. */
  
  result.SyntaxError = function(message, line, column) {
    this.name = 'SyntaxError';
    this.message = message;
    this.line = line;
    this.column = column;
  };
  
  result.SyntaxError.prototype = Error.prototype;
  
  return result;
})();

wikipeg.pegjs

start = line+

line = heading / list / text / eol

heading = bang:"!" text:text { return {type: "HEADING", value: text}; }

text = text:(word:word space:space? {
	return (typeof word === 'string') ? word + space :
		((space) ? [word, space] : word);
	})+ {
		var result = (function() {
			var res = [], bufStr = '';
			for (var i = 0; i < text.length; i++) {
				if (typeof text[i] !== 'string') {
					if (bufStr) {
						res.push(bufStr);
						bufStr = '';
					}
					res.push(text[i]);
				} else {
					bufStr += text[i];
				}
			}
			if (bufStr) {
				res.push(bufStr);
			}
			if (res.length === 1 && typeof res[0] === 'string') {
				return { type: 'TEXT', value: res[0] }
			} else if (res.length === 1) {
				return res[0];
			} else {
				return res;
			}
		}());
		return result;
	}

eol = end:"\n" { return "EOL"; }

space = ws:[ \t]+ { return ws.join(''); }

word = inline:inline { return inline; } /
	text:[^ \t\n]+ { return text.join(''); }

inline = "<<" text:[^>>]+ ">>" { return {type: 'TRANSCLUDE', value: text.join('')}; } /
	link:link { return link; }


link = "[[" text:[^\]\]|]+ "]]" { return {type: 'LINK', value: text.join('')}; } /
	"[[" name:[^\|]+ "|" link:[^\]\]]+ "]]" { return {type: 'LINK', value: {TITLE: name.join(''), LINK: link.join('')}}; } /
	firstCap:[A-Z] firstText:[a-z0-9]* secondCap:[A-Z]+ lastText:[0-9a-zA-Z]+ { return {type: 'WIKILINK', value: firstCap + firstText.join('') + secondCap.join('') + lastText.join('')}; }

list = list:ulist+ { return {type: 'ULIST', value: list}; } / list:olist+ {return {type: 'OLIST', value: list}; }

ulist = "*" space? text:text? eol? { return {type: 'ULI', value: text}; }

olist = "#" space? text:text? eol? { return {type: 'OLI', value: text}; }