diff options
| -rw-r--r-- | screenplain/richstring.py | 64 | ||||
| -rw-r--r-- | tests/richstring_test.py | 6 |
2 files changed, 49 insertions, 21 deletions
diff --git a/screenplain/richstring.py b/screenplain/richstring.py index e126ae4..c602966 100644 --- a/screenplain/richstring.py +++ b/screenplain/richstring.py @@ -203,6 +203,32 @@ underline = _CreateStyledString((Underline,)) empty_string = RichString() +# A special unicode character to use for a literal '*' +literal_star = u'\ue706' + +# All styles. Note: order matters! This is the order they are parsed. +all_styles = (Bold, Italic, Underline) + + +def _unescape(source): + """Converts backslash-escaped stars in a string to the magic + "literal star" character. + + >>> _unescape(r'\*hello\*') + u'\ue706hello\ue706' + + """ + return source.replace('\\*', literal_star) + + +def _demagic_literals(text): + """Converts "literal star" characters to actual stars: "*" + + >>> _demagic_literals(u'\ue706hello\ue706') + u'*hello*' + """ + return text.replace(literal_star, '*') + def parse_emphasis(source): """Parses emphasis markers like * and ** in a string @@ -215,15 +241,18 @@ def parse_emphasis(source): >>> parse_emphasis(u'**hello** there') (bold)(u'hello') + (plain)(u' there') """ - source = Bold.parse_re.sub( - Bold.start_magic + r'\1' + Bold.end_magic, source - ) - source = Italic.parse_re.sub( - Italic.start_magic + r'\1' + Italic.end_magic, source - ) - source = Underline.parse_re.sub( - Underline.start_magic + r'\1' + Underline.end_magic, source - ) + + # Convert escaped characters to magic characters so they aren't parsed + # as emphasis. + source = _unescape(source) + + for style in all_styles: + source = style.parse_re.sub( + style.start_magic + r'\1' + style.end_magic, source + ) + + # Convert magic characters back, so they are printable again. + source = _demagic_literals(source) styles = set() segments = [] @@ -240,18 +269,11 @@ def parse_emphasis(source): append(pos, end) pos = end + 1 magic = match.group(0) - if magic == Bold.start_magic: - styles.add(Bold) - elif magic == Bold.end_magic: - styles.remove(Bold) - elif magic == Italic.start_magic: - styles.add(Italic) - elif magic == Italic.end_magic: - styles.remove(Italic) - elif magic == Underline.start_magic: - styles.add(Underline) - elif magic == Underline.end_magic: - styles.remove(Underline) + for style in all_styles: + if magic == style.start_magic: + styles.add(style) + elif magic == style.end_magic: + styles.remove(style) append(pos, len(source)) return RichString(*segments) diff --git a/tests/richstring_test.py b/tests/richstring_test.py index 0e83aa1..5e5f7f5 100644 --- a/tests/richstring_test.py +++ b/tests/richstring_test.py @@ -199,3 +199,9 @@ class ParseEmphasisTests(unittest2.TestCase): parse_emphasis('**first** **second**'), bold('first') + plain(' ') + bold('second') ) + + def test_escaping_star_creates_a_literal_star(self): + self.assertEquals( + parse_emphasis(r'\*hello*'), + plain('*hello*') + ) |