| # |
| # Licensed to the Apache Software Foundation (ASF) under one |
| # or more contributor license agreements. See the NOTICE file |
| # distributed with this work for additional information |
| # regarding copyright ownership. The ASF licenses this file |
| # to you under the Apache License, Version 2.0 (the |
| # "License"); you may not use this file except in compliance |
| # with the License. You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, |
| # software distributed under the License is distributed on an |
| # "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| # KIND, either express or implied. See the License for the |
| # specific language governing permissions and limitations |
| # under the License. |
| # |
| import re, rfc822 |
| from lexer import Lexicon, LexError |
| from parser import Parser, ParseError |
| |
| l = Lexicon() |
| |
| LPAREN = l.define("LPAREN", r"\(") |
| RPAREN = l.define("LPAREN", r"\)") |
| SLASH = l.define("SLASH", r"/") |
| SEMI = l.define("SEMI", r";") |
| EQUAL = l.define("EQUAL", r"=") |
| TOKEN = l.define("TOKEN", r'[^()<>@,;:\\"/\[\]?= ]+') |
| STRING = l.define("STRING", r'"(?:[^\\"]|\\.)*"') |
| WSPACE = l.define("WSPACE", r"[ \n\r\t]+") |
| EOF = l.eof("EOF") |
| |
| LEXER = l.compile() |
| |
| def lex(st): |
| return LEXER.lex(st) |
| |
| class MimeTypeParser(Parser): |
| |
| def __init__(self, tokens): |
| Parser.__init__(self, [t for t in tokens if t.type is not WSPACE]) |
| |
| def parse(self): |
| result = self.mimetype() |
| self.eat(EOF) |
| return result |
| |
| def mimetype(self): |
| self.remove_comments() |
| self.reset() |
| |
| type = self.eat(TOKEN).value.lower() |
| self.eat(SLASH) |
| subtype = self.eat(TOKEN).value.lower() |
| |
| params = [] |
| while True: |
| if self.matches(SEMI): |
| params.append(self.parameter()) |
| else: |
| break |
| |
| return type, subtype, params |
| |
| def remove_comments(self): |
| while True: |
| self.eat_until(LPAREN, EOF) |
| if self.matches(LPAREN): |
| self.remove(*self.comment()) |
| else: |
| break |
| |
| def comment(self): |
| start = self.eat(LPAREN) |
| |
| while True: |
| self.eat_until(LPAREN, RPAREN) |
| if self.matches(LPAREN): |
| self.comment() |
| else: |
| break |
| |
| end = self.eat(RPAREN) |
| return start, end |
| |
| def parameter(self): |
| self.eat(SEMI) |
| name = self.eat(TOKEN).value |
| self.eat(EQUAL) |
| value = self.value() |
| return name, value |
| |
| def value(self): |
| if self.matches(TOKEN): |
| return self.eat().value |
| elif self.matches(STRING): |
| return rfc822.unquote(self.eat().value) |
| else: |
| raise ParseError(self.next(), TOKEN, STRING) |
| |
| def parse(addr): |
| return MimeTypeParser(lex(addr)).parse() |
| |
| __all__ = ["parse", "ParseError"] |