/** * Used to split a string of text in the language given by $locale into * space separated words. Ex: "acontinuousstringofwords" becomes * "a continuous string of words". It operates by scanning from the end of * the string to the front and splitting on the longest segment that is a * word. * * @param string $segment string to make into a string of space separated * words * @param string $locale IANA tag used to look up dictionary filter to * use to do this segmenting * @return string space separated words */ static function reverseMaximalMatch($segment, $locale) { $len = mb_strlen($segment); $cur_pos = $len - 1; if ($cur_pos < 1) { return $segment; } $out_segment = ""; $word_len = 2; $char_added = mb_substr($segment, $cur_pos, 1); $word_guess = $char_added; $is_ascii = mb_check_encoding($char_added, 'ASCII'); $was_space = trim($char_added) == ""; $added = false; $suffix_backup = -1; $suffix_check = true; while ($cur_pos >= 0) { $old_word_guess = $word_guess; $cur_pos--; $char_added = mb_substr($segment, $cur_pos, 1); $is_space = trim($char_added) == ""; if ($is_space && $was_space) { continue; } if (!$is_space) { $word_guess = $char_added . $word_guess; $was_space = false; } else { $was_space = true; } if ($suffix_check) { $is_suffix = NWordGrams::ngramsContains("*" . $word_guess, $locale, "segment"); } else { $is_suffix = false; } $suffix_check = true; $is_ascii = $is_ascii && mb_check_encoding($char_added, 'ASCII') && !$is_space; if ($is_suffix || $is_ascii) { $word_len++; $added = false; if ($is_suffix) { $suffix_backup = $cur_pos; $suffix_guess = $word_guess; } } else { if ($suffix_backup >= 0) { $cur_pos = $suffix_backup; $suffix_backup = -1; $suffix_check = false; $word_guess = $suffix_guess; $word_len = strlen($word_guess); } else { if (NWordGrams::ngramsContains($word_guess, $locale, "segment") || $is_space) { $out_segment .= " " . strrev($word_guess); $cur_pos--; $suffix_backup = -1; $word_len = 1; $word_guess = mb_substr($segment, $cur_pos, $word_len); $is_ascii = mb_check_encoding($word_guess, 'ASCII'); $was_space = trim($char_added) == ""; $word_len++; $added = true; } else { $word_len = 1; $suffix_backup = -1; $out_segment .= " " . strrev($old_word_guess); $word_guess = mb_substr($segment, $cur_pos, $word_len); $is_ascii = mb_check_encoding($word_guess, 'ASCII'); $was_space = trim($char_added) == ""; $word_len++; $added = true; } } } } if (!$added) { if (NWordGrams::ngramsContains($old_word_guess, $locale, "segment") || mb_check_encoding($old_word_guess, 'ASCII')) { $out_segment .= " " . strrev($old_word_guess); } else { $front = mb_substr($old_word_guess, 0, 1); $back = mb_substr($old_word_guess, 1); $out_segment .= " " . strrev($front) . " " . strrev($back); } } $out_segment = strrev($out_segment); return $out_segment; }