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'use strict';
// --------------------------------------------------------------------// Imports// --------------------------------------------------------------------
const MatchState = require('./MatchState');
const pexprs = require('./pexprs');
// --------------------------------------------------------------------// Private stuff// --------------------------------------------------------------------
function Matcher(grammar) {  this.grammar = grammar;  this.memoTable = [];  this.input = '';}
Matcher.prototype.getInput = function() {  return this.input;};
Matcher.prototype.setInput = function(str) {  if (this.input !== str) {    this.replaceInputRange(0, this.input.length, str);  }  return this;};
Matcher.prototype.replaceInputRange = function(startIdx, endIdx, str) {  const currentInput = this.input;  if (    startIdx < 0 ||    startIdx > currentInput.length ||    endIdx < 0 ||    endIdx > currentInput.length ||    startIdx > endIdx  ) {    throw new Error('Invalid indices: ' + startIdx + ' and ' + endIdx);  }
  // update input  this.input = currentInput.slice(0, startIdx) + str + currentInput.slice(endIdx);
  // update memo table (similar to the above)  const restOfMemoTable = this.memoTable.slice(endIdx);  this.memoTable.length = startIdx;  for (let idx = 0; idx < str.length; idx++) {    this.memoTable.push(undefined);  }  restOfMemoTable.forEach(function(posInfo) {    this.memoTable.push(posInfo);  }, this);
  // Invalidate memoRecs  for (let pos = 0; pos < startIdx; pos++) {    const posInfo = this.memoTable[pos];    if (posInfo) {      posInfo.clearObsoleteEntries(pos, startIdx);    }  }
  return this;};
Matcher.prototype.match = function(optStartApplicationStr) {  return this._match(this._getStartExpr(optStartApplicationStr), false);};
Matcher.prototype.trace = function(optStartApplicationStr) {  return this._match(this._getStartExpr(optStartApplicationStr), true);};
Matcher.prototype._match = function(startExpr, tracing, optPositionToRecordFailures) {  const state = new MatchState(this, startExpr, optPositionToRecordFailures);  return tracing ? state.getTrace() : state.getMatchResult();};
/*  Returns the starting expression for this Matcher's associated grammar. If `optStartApplicationStr`  is specified, it is a string expressing a rule application in the grammar. If not specified, the  grammar's default start rule will be used.*/Matcher.prototype._getStartExpr = function(optStartApplicationStr) {  const applicationStr = optStartApplicationStr || this.grammar.defaultStartRule;  if (!applicationStr) {    throw new Error('Missing start rule argument -- the grammar has no default start rule.');  }
  const startApp = this.grammar.parseApplication(applicationStr);  return new pexprs.Seq([startApp, pexprs.end]);};
// --------------------------------------------------------------------// Exports// --------------------------------------------------------------------
module.exports = Matcher;