parser.js

/*
 * Generated by PEG.js 0.10.0.
 *
 * http://pegjs.org/
 */

"use strict";

function peg$subclass(child, parent) {
  function ctor() { this.constructor = child; }
  ctor.prototype = parent.prototype;
  child.prototype = new ctor();
}

function peg$SyntaxError(message, expected, found, location) {
  this.message  = message;
  this.expected = expected;
  this.found    = found;
  this.location = location;
  this.name     = "SyntaxError";

  if (typeof Error.captureStackTrace === "function") {
    Error.captureStackTrace(this, peg$SyntaxError);
  }
}

peg$subclass(peg$SyntaxError, Error);

peg$SyntaxError.buildMessage = function(expected, found) {
  var DESCRIBE_EXPECTATION_FNS = {
        literal: function(expectation) {
          return "\"" + literalEscape(expectation.text) + "\"";
        },

        "class": function(expectation) {
          var escapedParts = "",
              i;

          for (i = 0; i < expectation.parts.length; i++) {
            escapedParts += expectation.parts[i] instanceof Array
              ? classEscape(expectation.parts[i][0]) + "-" + classEscape(expectation.parts[i][1])
              : classEscape(expectation.parts[i]);
          }

          return "[" + (expectation.inverted ? "^" : "") + escapedParts + "]";
        },

        any: function(expectation) {
          return "any character";
        },

        end: function(expectation) {
          return "end of input";
        },

        other: function(expectation) {
          return expectation.description;
        }
      };

  function hex(ch) {
    return ch.charCodeAt(0).toString(16).toUpperCase();
  }

  function literalEscape(s) {
    return s
      .replace(/\\/g, '\\\\')
      .replace(/"/g,  '\\"')
      .replace(/\0/g, '\\0')
      .replace(/\t/g, '\\t')
      .replace(/\n/g, '\\n')
      .replace(/\r/g, '\\r')
      .replace(/[\x00-\x0F]/g,          function(ch) { return '\\x0' + hex(ch); })
      .replace(/[\x10-\x1F\x7F-\x9F]/g, function(ch) { return '\\x'  + hex(ch); });
  }

  function classEscape(s) {
    return s
      .replace(/\\/g, '\\\\')
      .replace(/\]/g, '\\]')
      .replace(/\^/g, '\\^')
      .replace(/-/g,  '\\-')
      .replace(/\0/g, '\\0')
      .replace(/\t/g, '\\t')
      .replace(/\n/g, '\\n')
      .replace(/\r/g, '\\r')
      .replace(/[\x00-\x0F]/g,          function(ch) { return '\\x0' + hex(ch); })
      .replace(/[\x10-\x1F\x7F-\x9F]/g, function(ch) { return '\\x'  + hex(ch); });
  }

  function describeExpectation(expectation) {
    return DESCRIBE_EXPECTATION_FNS[expectation.type](expectation);
  }

  function describeExpected(expected) {
    var descriptions = new Array(expected.length),
        i, j;

    for (i = 0; i < expected.length; i++) {
      descriptions[i] = describeExpectation(expected[i]);
    }

    descriptions.sort();

    if (descriptions.length > 0) {
      for (i = 1, j = 1; i < descriptions.length; i++) {
        if (descriptions[i - 1] !== descriptions[i]) {
          descriptions[j] = descriptions[i];
          j++;
        }
      }
      descriptions.length = j;
    }

    switch (descriptions.length) {
      case 1:
        return descriptions[0];

      case 2:
        return descriptions[0] + " or " + descriptions[1];

      default:
        return descriptions.slice(0, -1).join(", ")
          + ", or "
          + descriptions[descriptions.length - 1];
    }
  }

  function describeFound(found) {
    return found ? "\"" + literalEscape(found) + "\"" : "end of input";
  }

  return "Expected " + describeExpected(expected) + " but " + describeFound(found) + " found.";
};

function peg$parse(input, options) {
  options = options !== void 0 ? options : {};

  var peg$FAILED = {},

      peg$startRuleFunctions = { start: peg$parsestart },
      peg$startRuleFunction  = peg$parsestart,

      peg$c0 = "+",
      peg$c1 = peg$literalExpectation("+", false),
      peg$c2 = function(left, right) { return left + right; },
      peg$c3 = "*",
      peg$c4 = peg$literalExpectation("*", false),
      peg$c5 = function(left, right) { return left * right; },
      peg$c6 = "(",
      peg$c7 = peg$literalExpectation("(", false),
      peg$c8 = ")",
      peg$c9 = peg$literalExpectation(")", false),
      peg$c10 = function(additive) { return additive; },
      peg$c11 = peg$otherExpectation("integer"),
      peg$c12 = /^[0-9]/,
      peg$c13 = peg$classExpectation([["0", "9"]], false, false),
      peg$c14 = function(digits) { return parseInt(digits.join(""), 10); },

      peg$currPos          = 0,
      peg$savedPos         = 0,
      peg$posDetailsCache  = [{ line: 1, column: 1 }],
      peg$maxFailPos       = 0,
      peg$maxFailExpected  = [],
      peg$silentFails      = 0,

      peg$result;

  if ("startRule" in options) {
    if (!(options.startRule in peg$startRuleFunctions)) {
      throw new Error("Can't start parsing from rule \"" + options.startRule + "\".");
    }

    peg$startRuleFunction = peg$startRuleFunctions[options.startRule];
  }

  function text() {
    return input.substring(peg$savedPos, peg$currPos);
  }

  function location() {
    return peg$computeLocation(peg$savedPos, peg$currPos);
  }

  function expected(description, location) {
    location = location !== void 0 ? location : peg$computeLocation(peg$savedPos, peg$currPos)

    throw peg$buildStructuredError(
      [peg$otherExpectation(description)],
      input.substring(peg$savedPos, peg$currPos),
      location
    );
  }

  function error(message, location) {
    location = location !== void 0 ? location : peg$computeLocation(peg$savedPos, peg$currPos)

    throw peg$buildSimpleError(message, location);
  }

  function peg$literalExpectation(text, ignoreCase) {
    return { type: "literal", text: text, ignoreCase: ignoreCase };
  }

  function peg$classExpectation(parts, inverted, ignoreCase) {
    return { type: "class", parts: parts, inverted: inverted, ignoreCase: ignoreCase };
  }

  function peg$anyExpectation() {
    return { type: "any" };
  }

  function peg$endExpectation() {
    return { type: "end" };
  }

  function peg$otherExpectation(description) {
    return { type: "other", description: description };
  }

  function peg$computePosDetails(pos) {
    var details = peg$posDetailsCache[pos], p;

    if (details) {
      return details;
    } else {
      p = pos - 1;
      while (!peg$posDetailsCache[p]) {
        p--;
      }

      details = peg$posDetailsCache[p];
      details = {
        line:   details.line,
        column: details.column
      };

      while (p < pos) {
        if (input.charCodeAt(p) === 10) {
          details.line++;
          details.column = 1;
        } else {
          details.column++;
        }

        p++;
      }

      peg$posDetailsCache[pos] = details;
      return details;
    }
  }

  function peg$computeLocation(startPos, endPos) {
    var startPosDetails = peg$computePosDetails(startPos),
        endPosDetails   = peg$computePosDetails(endPos);

    return {
      start: {
        offset: startPos,
        line:   startPosDetails.line,
        column: startPosDetails.column
      },
      end: {
        offset: endPos,
        line:   endPosDetails.line,
        column: endPosDetails.column
      }
    };
  }

  function peg$fail(expected) {
    if (peg$currPos < peg$maxFailPos) { return; }

    if (peg$currPos > peg$maxFailPos) {
      peg$maxFailPos = peg$currPos;
      peg$maxFailExpected = [];
    }

    peg$maxFailExpected.push(expected);
  }

  function peg$buildSimpleError(message, location) {
    return new peg$SyntaxError(message, null, null, location);
  }

  function peg$buildStructuredError(expected, found, location) {
    return new peg$SyntaxError(
      peg$SyntaxError.buildMessage(expected, found),
      expected,
      found,
      location
    );
  }

  function peg$parsestart() {
    var s0;

    s0 = peg$parseadditive();

    return s0;
  }

  function peg$parseadditive() {
    var s0, s1, s2, s3;

    s0 = peg$currPos;
    s1 = peg$parsemultiplicative();
    if (s1 !== peg$FAILED) {
      if (input.charCodeAt(peg$currPos) === 43) {
        s2 = peg$c0;
        peg$currPos++;
      } else {
        s2 = peg$FAILED;
        if (peg$silentFails === 0) { peg$fail(peg$c1); }
      }
      if (s2 !== peg$FAILED) {
        s3 = peg$parseadditive();
        if (s3 !== peg$FAILED) {
          peg$savedPos = s0;
          s1 = peg$c2(s1, s3);
          s0 = s1;
        } else {
          peg$currPos = s0;
          s0 = peg$FAILED;
        }
      } else {
        peg$currPos = s0;
        s0 = peg$FAILED;
      }
    } else {
      peg$currPos = s0;
      s0 = peg$FAILED;
    }
    if (s0 === peg$FAILED) {
      s0 = peg$parsemultiplicative();
    }

    return s0;
  }

  function peg$parsemultiplicative() {
    var s0, s1, s2, s3;

    s0 = peg$currPos;
    s1 = peg$parseprimary();
    if (s1 !== peg$FAILED) {
      if (input.charCodeAt(peg$currPos) === 42) {
        s2 = peg$c3;
        peg$currPos++;
      } else {
        s2 = peg$FAILED;
        if (peg$silentFails === 0) { peg$fail(peg$c4); }
      }
      if (s2 !== peg$FAILED) {
        s3 = peg$parsemultiplicative();
        if (s3 !== peg$FAILED) {
          peg$savedPos = s0;
          s1 = peg$c5(s1, s3);
          s0 = s1;
        } else {
          peg$currPos = s0;
          s0 = peg$FAILED;
        }
      } else {
        peg$currPos = s0;
        s0 = peg$FAILED;
      }
    } else {
      peg$currPos = s0;
      s0 = peg$FAILED;
    }
    if (s0 === peg$FAILED) {
      s0 = peg$parseprimary();
    }

    return s0;
  }

  function peg$parseprimary() {
    var s0, s1, s2, s3;

    s0 = peg$parseinteger();
    if (s0 === peg$FAILED) {
      s0 = peg$currPos;
      if (input.charCodeAt(peg$currPos) === 40) {
        s1 = peg$c6;
        peg$currPos++;
      } else {
        s1 = peg$FAILED;
        if (peg$silentFails === 0) { peg$fail(peg$c7); }
      }
      if (s1 !== peg$FAILED) {
        s2 = peg$parseadditive();
        if (s2 !== peg$FAILED) {
          if (input.charCodeAt(peg$currPos) === 41) {
            s3 = peg$c8;
            peg$currPos++;
          } else {
            s3 = peg$FAILED;
            if (peg$silentFails === 0) { peg$fail(peg$c9); }
          }
          if (s3 !== peg$FAILED) {
            peg$savedPos = s0;
            s1 = peg$c10(s2);
            s0 = s1;
          } else {
            peg$currPos = s0;
            s0 = peg$FAILED;
          }
        } else {
          peg$currPos = s0;
          s0 = peg$FAILED;
        }
      } else {
        peg$currPos = s0;
        s0 = peg$FAILED;
      }
    }

    return s0;
  }

  function peg$parseinteger() {
    var s0, s1, s2;

    peg$silentFails++;
    s0 = peg$currPos;
    s1 = [];
    if (peg$c12.test(input.charAt(peg$currPos))) {
      s2 = input.charAt(peg$currPos);
      peg$currPos++;
    } else {
      s2 = peg$FAILED;
      if (peg$silentFails === 0) { peg$fail(peg$c13); }
    }
    if (s2 !== peg$FAILED) {
      while (s2 !== peg$FAILED) {
        s1.push(s2);
        if (peg$c12.test(input.charAt(peg$currPos))) {
          s2 = input.charAt(peg$currPos);
          peg$currPos++;
        } else {
          s2 = peg$FAILED;
          if (peg$silentFails === 0) { peg$fail(peg$c13); }
        }
      }
    } else {
      s1 = peg$FAILED;
    }
    if (s1 !== peg$FAILED) {
      peg$savedPos = s0;
      s1 = peg$c14(s1);
    }
    s0 = s1;
    peg$silentFails--;
    if (s0 === peg$FAILED) {
      s1 = peg$FAILED;
      if (peg$silentFails === 0) { peg$fail(peg$c11); }
    }

    return s0;
  }

  peg$result = peg$startRuleFunction();

  if (peg$result !== peg$FAILED && peg$currPos === input.length) {
    return peg$result;
  } else {
    if (peg$result !== peg$FAILED && peg$currPos < input.length) {
      peg$fail(peg$endExpectation());
    }

    throw peg$buildStructuredError(
      peg$maxFailExpected,
      peg$maxFailPos < input.length ? input.charAt(peg$maxFailPos) : null,
      peg$maxFailPos < input.length
        ? peg$computeLocation(peg$maxFailPos, peg$maxFailPos + 1)
        : peg$computeLocation(peg$maxFailPos, peg$maxFailPos)
    );
  }
}

module.exports = {
  SyntaxError: peg$SyntaxError,
  parse:       peg$parse
};