Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.11/site-packages/genshi/template/interpolation.py: 17%

1# -*- coding: utf-8 -*- 

2# 

3# Copyright (C) 2007-2009 Edgewall Software 

4# All rights reserved. 

5# 

6# This software is licensed as described in the file COPYING, which 

7# you should have received as part of this distribution. The terms 

8# are also available at http://genshi.edgewall.org/wiki/License. 

9# 

10# This software consists of voluntary contributions made by many 

11# individuals. For the exact contribution history, see the revision 

12# history and logs, available at http://genshi.edgewall.org/log/. 

13 

14"""String interpolation routines, i.e. the splitting up a given text into some 

15parts that are literal strings, and others that are Python expressions. 

16""" 

17 

18from itertools import chain 

19import re 

20from tokenize import PseudoToken 

21 

22from genshi.core import TEXT 

23from genshi.template.base import TemplateSyntaxError, EXPR 

24from genshi.template.eval import Expression 

25 

26__all__ = ['interpolate'] 

27__docformat__ = 'restructuredtext en' 

28 

29NAMESTART = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_' 

30NAMECHARS = NAMESTART + '.0123456789' 

31PREFIX = '$' 

32 

33token_re = re.compile('(?s)%s|%s' % ( 

34 r'[uU]?[rR]?("""|\'\'\')((?<!\\)\\\1|.)*?\1', 

35 PseudoToken 

36)) 

37 

38 

39def interpolate(text, filepath=None, lineno=-1, offset=0, lookup='strict'): 

40 """Parse the given string and extract expressions. 

41  

42 This function is a generator that yields `TEXT` events for literal strings, 

43 and `EXPR` events for expressions, depending on the results of parsing the 

44 string. 

45  

46 >>> for kind, data, pos in interpolate("hey ${foo}bar"): 

47 ... print('%s %r' % (kind, data)) 

48 TEXT 'hey ' 

49 EXPR Expression('foo') 

50 TEXT 'bar' 

51  

52 :param text: the text to parse 

53 :param filepath: absolute path to the file in which the text was found 

54 (optional) 

55 :param lineno: the line number at which the text was found (optional) 

56 :param offset: the column number at which the text starts in the source 

57 (optional) 

58 :param lookup: the variable lookup mechanism; either "lenient" (the 

59 default), "strict", or a custom lookup class 

60 :return: a list of `TEXT` and `EXPR` events 

61 :raise TemplateSyntaxError: when a syntax error in an expression is 

62 encountered 

63 """ 

64 pos = [filepath, lineno, offset] 

65 

66 textbuf = [] 

67 textpos = None 

68 for is_expr, chunk in chain(lex(text, pos, filepath), [(True, '')]): 

69 if is_expr: 

70 if textbuf: 

71 yield TEXT, ''.join(textbuf), textpos 

72 del textbuf[:] 

73 textpos = None 

74 if chunk: 

75 try: 

76 expr = Expression(chunk.strip(), pos[0], pos[1], 

77 lookup=lookup) 

78 yield EXPR, expr, tuple(pos) 

79 except SyntaxError as err: 

80 raise TemplateSyntaxError(err, filepath, pos[1], 

81 pos[2] + (err.offset or 0)) 

82 else: 

83 textbuf.append(chunk) 

84 if textpos is None: 

85 textpos = tuple(pos) 

86 

87 if '\n' in chunk: 

88 lines = chunk.splitlines() 

89 pos[1] += len(lines) - 1 

90 pos[2] += len(lines[-1]) 

91 else: 

92 pos[2] += len(chunk) 

93 

94 

95def lex(text, textpos, filepath): 

96 offset = pos = 0 

97 end = len(text) 

98 escaped = False 

99 

100 while 1: 

101 if escaped: 

102 offset = text.find(PREFIX, offset + 2) 

103 escaped = False 

104 else: 

105 offset = text.find(PREFIX, pos) 

106 if offset < 0 or offset == end - 1: 

107 break 

108 next = text[offset + 1] 

109 

110 if next == '{': 

111 if offset > pos: 

112 yield False, text[pos:offset] 

113 pos = offset + 2 

114 level = 1 

115 while level: 

116 match = token_re.match(text, pos) 

117 if match is None or not match.group(): 

118 # if there isn't a match or the match is the empty 

119 # string, we're not going to match up braces ever 

120 raise TemplateSyntaxError('invalid syntax', filepath, 

121 *textpos[1:]) 

122 pos = match.end() 

123 tstart, tend = match.regs[3] 

124 token = text[tstart:tend] 

125 if token == '{': 

126 level += 1 

127 elif token == '}': 

128 level -= 1 

129 yield True, text[offset + 2:pos - 1] 

130 

131 elif next in NAMESTART: 

132 if offset > pos: 

133 yield False, text[pos:offset] 

134 pos = offset 

135 pos += 1 

136 while pos < end: 

137 char = text[pos] 

138 if char not in NAMECHARS: 

139 break 

140 pos += 1 

141 yield True, text[offset + 1:pos].strip() 

142 

143 elif not escaped and next == PREFIX: 

144 if offset > pos: 

145 yield False, text[pos:offset] 

146 escaped = True 

147 pos = offset + 1 

148 

149 else: 

150 yield False, text[pos:offset + 1] 

151 pos = offset + 1 

152 

153 if pos < end: 

154 yield False, text[pos:]