diff options
Diffstat (limited to 'intl/icu/source/python/icutools/databuilder/comment_stripper.py')
| -rw-r--r-- | intl/icu/source/python/icutools/databuilder/comment_stripper.py | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/intl/icu/source/python/icutools/databuilder/comment_stripper.py b/intl/icu/source/python/icutools/databuilder/comment_stripper.py new file mode 100644 index 0000000000..4001f2f675 --- /dev/null +++ b/intl/icu/source/python/icutools/databuilder/comment_stripper.py @@ -0,0 +1,51 @@ +# Copyright (C) 2018 and later: Unicode, Inc. and others. +# License & terms of use: http://www.unicode.org/copyright.html + +import io + +class CommentStripper(object): + """Removes lines starting with "//" from a file stream.""" + + def __init__(self, f): + self.f = f + self.state = 0 + + def read(self, size=-1): + bytes = self.f.read(size) + # TODO: Do we need to read more bytes if comments were stripped + # in order to obey the size request? + return "".join(self._strip_comments(bytes)) + + def _strip_comments(self, bytes): + for byte in bytes: + if self.state == 0: + # state 0: start of a line + if byte == "/": + self.state = 1 + elif byte == "\n": + self.state = 0 + yield byte + else: + self.state = 2 + yield byte + elif self.state == 1: + # state 1: read a single '/' + if byte == "/": + self.state = 3 + elif byte == "\n": + self.state = 0 + yield "/" # the one that was skipped + yield "\n" + else: + self.state = 2 + yield "/" # the one that was skipped + yield byte + elif self.state == 2: + # state 2: middle of a line, no comment + if byte == "\n": + self.state = 0 + yield byte + elif self.state == 3: + # state 3: inside a comment + if byte == "\n": + self.state = 0 |