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| from __future__ import annotations | |
| from fontTools.misc.textTools import byteord, tostr | |
| import re | |
| from bisect import bisect_right | |
| from typing import Literal, TypeVar, overload | |
| try: | |
| # use unicodedata backport compatible with python2: | |
| # https://github.com/fonttools/unicodedata2 | |
| from unicodedata2 import * | |
| except ImportError: # pragma: no cover | |
| # fall back to built-in unicodedata (possibly outdated) | |
| from unicodedata import * | |
| from . import Blocks, Scripts, ScriptExtensions, OTTags | |
| __all__ = [ | |
| # names from built-in unicodedata module | |
| "lookup", | |
| "name", | |
| "decimal", | |
| "digit", | |
| "numeric", | |
| "category", | |
| "bidirectional", | |
| "combining", | |
| "east_asian_width", | |
| "mirrored", | |
| "decomposition", | |
| "normalize", | |
| "unidata_version", | |
| "ucd_3_2_0", | |
| # additonal functions | |
| "block", | |
| "script", | |
| "script_extension", | |
| "script_name", | |
| "script_code", | |
| "script_horizontal_direction", | |
| "ot_tags_from_script", | |
| "ot_tag_to_script", | |
| ] | |
| def script(char): | |
| """Return the four-letter script code assigned to the Unicode character | |
| 'char' as string. | |
| >>> script("a") | |
| 'Latn' | |
| >>> script(",") | |
| 'Zyyy' | |
| >>> script(chr(0x10FFFF)) | |
| 'Zzzz' | |
| """ | |
| code = byteord(char) | |
| # 'bisect_right(a, x, lo=0, hi=len(a))' returns an insertion point which | |
| # comes after (to the right of) any existing entries of x in a, and it | |
| # partitions array a into two halves so that, for the left side | |
| # all(val <= x for val in a[lo:i]), and for the right side | |
| # all(val > x for val in a[i:hi]). | |
| # Our 'SCRIPT_RANGES' is a sorted list of ranges (only their starting | |
| # breakpoints); we want to use `bisect_right` to look up the range that | |
| # contains the given codepoint: i.e. whose start is less than or equal | |
| # to the codepoint. Thus, we subtract -1 from the index returned. | |
| i = bisect_right(Scripts.RANGES, code) | |
| return Scripts.VALUES[i - 1] | |
| def script_extension(char): | |
| """Return the script extension property assigned to the Unicode character | |
| 'char' as a set of string. | |
| >>> script_extension("a") == {'Latn'} | |
| True | |
| >>> script_extension(chr(0x060C)) == {'Nkoo', 'Arab', 'Rohg', 'Thaa', 'Syrc', 'Gara', 'Yezi'} | |
| True | |
| >>> script_extension(chr(0x10FFFF)) == {'Zzzz'} | |
| True | |
| """ | |
| code = byteord(char) | |
| i = bisect_right(ScriptExtensions.RANGES, code) | |
| value = ScriptExtensions.VALUES[i - 1] | |
| if value is None: | |
| # code points not explicitly listed for Script Extensions | |
| # have as their value the corresponding Script property value | |
| return {script(char)} | |
| return value | |
| def script_name(code, default=KeyError): | |
| """Return the long, human-readable script name given a four-letter | |
| Unicode script code. | |
| If no matching name is found, a KeyError is raised by default. | |
| You can use the 'default' argument to return a fallback value (e.g. | |
| 'Unknown' or None) instead of throwing an error. | |
| """ | |
| try: | |
| return str(Scripts.NAMES[code].replace("_", " ")) | |
| except KeyError: | |
| if isinstance(default, type) and issubclass(default, KeyError): | |
| raise | |
| return default | |
| _normalize_re = re.compile(r"[-_ ]+") | |
| def _normalize_property_name(string): | |
| """Remove case, strip space, '-' and '_' for loose matching.""" | |
| return _normalize_re.sub("", string).lower() | |
| _SCRIPT_CODES = {_normalize_property_name(v): k for k, v in Scripts.NAMES.items()} | |
| def script_code(script_name, default=KeyError): | |
| """Returns the four-letter Unicode script code from its long name | |
| If no matching script code is found, a KeyError is raised by default. | |
| You can use the 'default' argument to return a fallback string (e.g. | |
| 'Zzzz' or None) instead of throwing an error. | |
| """ | |
| normalized_name = _normalize_property_name(script_name) | |
| try: | |
| return _SCRIPT_CODES[normalized_name] | |
| except KeyError: | |
| if isinstance(default, type) and issubclass(default, KeyError): | |
| raise | |
| return default | |
| # The data on script direction is taken from Harfbuzz source code: | |
| # https://github.com/harfbuzz/harfbuzz/blob/3.2.0/src/hb-common.cc#L514-L613 | |
| # This in turn references the following "Script_Metadata" document: | |
| # https://docs.google.com/spreadsheets/d/1Y90M0Ie3MUJ6UVCRDOypOtijlMDLNNyyLk36T6iMu0o | |
| RTL_SCRIPTS = { | |
| # Unicode-1.1 additions | |
| "Arab", # Arabic | |
| "Hebr", # Hebrew | |
| # Unicode-3.0 additions | |
| "Syrc", # Syriac | |
| "Thaa", # Thaana | |
| # Unicode-4.0 additions | |
| "Cprt", # Cypriot | |
| # Unicode-4.1 additions | |
| "Khar", # Kharoshthi | |
| # Unicode-5.0 additions | |
| "Phnx", # Phoenician | |
| "Nkoo", # Nko | |
| # Unicode-5.1 additions | |
| "Lydi", # Lydian | |
| # Unicode-5.2 additions | |
| "Avst", # Avestan | |
| "Armi", # Imperial Aramaic | |
| "Phli", # Inscriptional Pahlavi | |
| "Prti", # Inscriptional Parthian | |
| "Sarb", # Old South Arabian | |
| "Orkh", # Old Turkic | |
| "Samr", # Samaritan | |
| # Unicode-6.0 additions | |
| "Mand", # Mandaic | |
| # Unicode-6.1 additions | |
| "Merc", # Meroitic Cursive | |
| "Mero", # Meroitic Hieroglyphs | |
| # Unicode-7.0 additions | |
| "Mani", # Manichaean | |
| "Mend", # Mende Kikakui | |
| "Nbat", # Nabataean | |
| "Narb", # Old North Arabian | |
| "Palm", # Palmyrene | |
| "Phlp", # Psalter Pahlavi | |
| # Unicode-8.0 additions | |
| "Hatr", # Hatran | |
| "Hung", # Old Hungarian | |
| # Unicode-9.0 additions | |
| "Adlm", # Adlam | |
| # Unicode-11.0 additions | |
| "Rohg", # Hanifi Rohingya | |
| "Sogo", # Old Sogdian | |
| "Sogd", # Sogdian | |
| # Unicode-12.0 additions | |
| "Elym", # Elymaic | |
| # Unicode-13.0 additions | |
| "Chrs", # Chorasmian | |
| "Yezi", # Yezidi | |
| # Unicode-14.0 additions | |
| "Ougr", # Old Uyghur | |
| } | |
| HorizDirection = Literal["RTL", "LTR"] | |
| T = TypeVar("T") | |
| def script_horizontal_direction(script_code: str, default: T) -> HorizDirection | T: ... | |
| def script_horizontal_direction( | |
| script_code: str, default: type[KeyError] = KeyError | |
| ) -> HorizDirection: ... | |
| def script_horizontal_direction( | |
| script_code: str, default: T | type[KeyError] = KeyError | |
| ) -> HorizDirection | T: | |
| """Return "RTL" for scripts that contain right-to-left characters | |
| according to the Bidi_Class property. Otherwise return "LTR". | |
| """ | |
| if script_code not in Scripts.NAMES: | |
| if isinstance(default, type) and issubclass(default, KeyError): | |
| raise default(script_code) | |
| return default | |
| return "RTL" if script_code in RTL_SCRIPTS else "LTR" | |
| def block(char): | |
| """Return the block property assigned to the Unicode character 'char' | |
| as a string. | |
| >>> block("a") | |
| 'Basic Latin' | |
| >>> block(chr(0x060C)) | |
| 'Arabic' | |
| >>> block(chr(0xEFFFF)) | |
| 'No_Block' | |
| """ | |
| code = byteord(char) | |
| i = bisect_right(Blocks.RANGES, code) | |
| return Blocks.VALUES[i - 1] | |
| def ot_tags_from_script(script_code): | |
| """Return a list of OpenType script tags associated with a given | |
| Unicode script code. | |
| Return ['DFLT'] script tag for invalid/unknown script codes. | |
| """ | |
| if script_code in OTTags.SCRIPT_EXCEPTIONS: | |
| return [OTTags.SCRIPT_EXCEPTIONS[script_code]] | |
| if script_code not in Scripts.NAMES: | |
| return [OTTags.DEFAULT_SCRIPT] | |
| script_tags = [script_code[0].lower() + script_code[1:]] | |
| if script_code in OTTags.NEW_SCRIPT_TAGS: | |
| script_tags.extend(OTTags.NEW_SCRIPT_TAGS[script_code]) | |
| script_tags.reverse() # last in, first out | |
| return script_tags | |
| def ot_tag_to_script(tag): | |
| """Return the Unicode script code for the given OpenType script tag, or | |
| None for "DFLT" tag or if there is no Unicode script associated with it. | |
| Raises ValueError if the tag is invalid. | |
| """ | |
| tag = tostr(tag).strip() | |
| if not tag or " " in tag or len(tag) > 4: | |
| raise ValueError("invalid OpenType tag: %r" % tag) | |
| if tag in OTTags.SCRIPT_ALIASES: | |
| tag = OTTags.SCRIPT_ALIASES[tag] | |
| while len(tag) != 4: | |
| tag += str(" ") # pad with spaces | |
| if tag == OTTags.DEFAULT_SCRIPT: | |
| # it's unclear which Unicode script the "DFLT" OpenType tag maps to, | |
| # so here we return None | |
| return None | |
| if tag in OTTags.NEW_SCRIPT_TAGS_REVERSED: | |
| return OTTags.NEW_SCRIPT_TAGS_REVERSED[tag] | |
| if tag in OTTags.SCRIPT_EXCEPTIONS_REVERSED: | |
| return OTTags.SCRIPT_EXCEPTIONS_REVERSED[tag] | |
| # This side of the conversion is fully algorithmic | |
| # Any spaces at the end of the tag are replaced by repeating the last | |
| # letter. Eg 'nko ' -> 'Nkoo'. | |
| # Change first char to uppercase | |
| script_code = tag[0].upper() + tag[1] | |
| for i in range(2, 4): | |
| script_code += script_code[i - 1] if tag[i] == " " else tag[i] | |
| if script_code not in Scripts.NAMES: | |
| return None | |
| return script_code | |