Source code for fontTools.voltLib.lexer

from fontTools.voltLib.error import VoltLibError

[docs]class Lexer(object): NUMBER = "NUMBER" STRING = "STRING" NAME = "NAME" NEWLINE = "NEWLINE" CHAR_WHITESPACE_ = " \t" CHAR_NEWLINE_ = "\r\n" CHAR_DIGIT_ = "0123456789" CHAR_UC_LETTER_ = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" CHAR_LC_LETTER_ = "abcdefghijklmnopqrstuvwxyz" CHAR_UNDERSCORE_ = "_" CHAR_PERIOD_ = "." CHAR_NAME_START_ = CHAR_UC_LETTER_ + CHAR_LC_LETTER_ + CHAR_PERIOD_ + \ CHAR_UNDERSCORE_ CHAR_NAME_CONTINUATION_ = CHAR_NAME_START_ + CHAR_DIGIT_ def __init__(self, text, filename): self.filename_ = filename self.line_ = 1 self.pos_ = 0 self.line_start_ = 0 self.text_ = text self.text_length_ = len(text) def __iter__(self): return self
[docs] def next(self): # Python 2 return self.__next__()
def __next__(self): # Python 3 while True: token_type, token, location = self.next_() if token_type not in {Lexer.NEWLINE}: return (token_type, token, location)
[docs] def location_(self): column = self.pos_ - self.line_start_ + 1 return (self.filename_ or "<volt>", self.line_, column)
[docs] def next_(self): self.scan_over_(Lexer.CHAR_WHITESPACE_) location = self.location_() start = self.pos_ text = self.text_ limit = len(text) if start >= limit: raise StopIteration() cur_char = text[start] next_char = text[start + 1] if start + 1 < limit else None if cur_char == "\n": self.pos_ += 1 self.line_ += 1 self.line_start_ = self.pos_ return (Lexer.NEWLINE, None, location) if cur_char == "\r": self.pos_ += (2 if next_char == "\n" else 1) self.line_ += 1 self.line_start_ = self.pos_ return (Lexer.NEWLINE, None, location) if cur_char == '"': self.pos_ += 1 self.scan_until_('"\r\n') if self.pos_ < self.text_length_ and self.text_[self.pos_] == '"': self.pos_ += 1 return (Lexer.STRING, text[start + 1:self.pos_ - 1], location) else: raise VoltLibError("Expected '\"' to terminate string", location) if cur_char in Lexer.CHAR_NAME_START_: self.pos_ += 1 self.scan_over_(Lexer.CHAR_NAME_CONTINUATION_) token = text[start:self.pos_] return (Lexer.NAME, token, location) if cur_char in Lexer.CHAR_DIGIT_: self.scan_over_(Lexer.CHAR_DIGIT_) return (Lexer.NUMBER, int(text[start:self.pos_], 10), location) if cur_char == "-" and next_char in Lexer.CHAR_DIGIT_: self.pos_ += 1 self.scan_over_(Lexer.CHAR_DIGIT_) return (Lexer.NUMBER, int(text[start:self.pos_], 10), location) raise VoltLibError("Unexpected character: '%s'" % cur_char, location)
[docs] def scan_over_(self, valid): p = self.pos_ while p < self.text_length_ and self.text_[p] in valid: p += 1 self.pos_ = p
[docs] def scan_until_(self, stop_at): p = self.pos_ while p < self.text_length_ and self.text_[p] not in stop_at: p += 1 self.pos_ = p