| |
| |
| |
| |
| """ |
| The implementation of tokenizer according to Thai Character Clusters (TCCs) |
| rules proposed by `Theeramunkong et al. 2000. \ |
| <http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.59.2548>`_ |
| and improved rules that are used in newmm |
| |
| Credits: |
| * TCC: Jakkrit TeCho |
| * Grammar: Wittawat Jitkrittum (`link to the source file \ |
| <https://github.com/wittawatj/jtcc/blob/master/TCC.g>`_) |
| * Python code: Korakot Chaovavanich |
| """ |
| import re |
| from typing import List, Set |
|
|
| _RE_TCC = ( |
| """\ |
| เc็ck |
| เcctาะk |
| เccีtยะk |
| เccีtย(?=[เ-ไก-ฮ]|$)k |
| เcc็ck |
| เcิc์ck |
| เcิtck |
| เcีtยะ?k |
| เcืtอะ?k |
| เc[ิีุู]tย(?=[เ-ไก-ฮ]|$)k |
| เctา?ะ?k |
| cัtวะk |
| c[ัื]tc[ุิะ]?k |
| c[ิุู]์ |
| c[ะ-ู]tk |
| cรรc์ |
| c็ |
| ct[ะาำ]?k |
| ck |
| แc็c |
| แcc์ |
| แctะ |
| แcc็c |
| แccc์ |
| โctะ |
| [เ-ไ]ct |
| ก็ |
| อึ |
| หึ |
| """.replace( |
| "k", "(cc?[dิ]?[์])?" |
| ) |
| .replace("c", "[ก-ฮ]") |
| .replace("t", "[่-๋]?") |
| .replace("d", "อูอุ".replace("อ", "")) |
| .split() |
| ) |
|
|
| _PAT_TCC = re.compile("|".join(_RE_TCC)) |
|
|
|
|
| def tcc(text: str) -> str: |
| """ |
| TCC generator which generates Thai Character Clusters |
| |
| :param str text: text to be tokenized into character clusters |
| :return: subwords (character clusters) |
| :rtype: Iterator[str] |
| """ |
| if not text or not isinstance(text, str): |
| return "" |
|
|
| len_text = len(text) |
| p = 0 |
| while p < len_text: |
| m = _PAT_TCC.match(text[p:]) |
| if m: |
| n = m.span()[1] |
| else: |
| n = 1 |
| yield text[p : p + n] |
| p += n |
|
|
|
|
| def tcc_pos(text: str) -> Set[int]: |
| """ |
| TCC positions |
| |
| :param str text: text to be tokenized into character clusters |
| :return: list of the ending position of subwords |
| :rtype: set[int] |
| """ |
| if not text or not isinstance(text, str): |
| return set() |
|
|
| p_set = set() |
| p = 0 |
| for w in tcc(text): |
| p += len(w) |
| p_set.add(p) |
|
|
| return p_set |
|
|
|
|
| def segment(text: str) -> List[str]: |
| """ |
| Subword segmentation |
| |
| :param str text: text to be tokenized into character clusters |
| :return: list of subwords (character clusters), tokenized from the text |
| :rtype: list[str] |
| |
| """ |
|
|
| return list(tcc(text)) |
|
|
