match.hpp

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/*
 * Copyright (c) 2004 Shane Beasley.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#ifndef MATCH_HPP_20040515T221421
#define MATCH_HPP_20040515T221421

#include <stdexcept>

namespace eloi {
  /**
   * Determine conformance of a subject string to a pattern formatted like so:
   * - The sequence \x, where x is any character, matches that character.
   * - * matches zero or more characters.
   * - ? matches exactly one character.
   * - Any other character matches itself.
   * @return true if subject matches the pattern, false otherwise
   **/
  template <typename InIt>
  bool
  match (InIt subject, InIt subjectEnd, InIt pattern, InIt patternEnd) {
    while (pattern != patternEnd) {
      switch (*pattern) {
      case '*':
	if (++pattern != patternEnd) {
	  while (subject != subjectEnd) {
	    if (match(subject, subjectEnd, pattern, patternEnd)) return true;
	    ++subject;
	  }

	  return false;
	}

	return true;

      case '?':
	if (subject != subjectEnd) break;
	return false;

      case '\\':
	if (++pattern == patternEnd) {
	  throw std::runtime_error("eloi::match: pattern cannot end with '\\'");
	}

	/*
	 * fall through
	 */

      default:
	if (subject != subjectEnd && *subject == *pattern) break;
	return false;
      }

      ++subject;
      ++pattern;
    }

    return (subject == subjectEnd);
  }
}

#endif