Show More
@@ -1,114 +1,116 | |||
|
1 | 1 | """Latex filters. |
|
2 | 2 | |
|
3 | 3 | Module of useful filters for processing Latex within Jinja latex templates. |
|
4 | 4 | """ |
|
5 | 5 | #----------------------------------------------------------------------------- |
|
6 | 6 | # Copyright (c) 2013, the IPython Development Team. |
|
7 | 7 | # |
|
8 | 8 | # Distributed under the terms of the Modified BSD License. |
|
9 | 9 | # |
|
10 | 10 | # The full license is in the file COPYING.txt, distributed with this software. |
|
11 | 11 | #----------------------------------------------------------------------------- |
|
12 | 12 | |
|
13 | 13 | #----------------------------------------------------------------------------- |
|
14 | 14 | # Imports |
|
15 | 15 | #----------------------------------------------------------------------------- |
|
16 | 16 | import re |
|
17 | 17 | |
|
18 | 18 | #----------------------------------------------------------------------------- |
|
19 | 19 | # Globals and constants |
|
20 | 20 | #----------------------------------------------------------------------------- |
|
21 | 21 | |
|
22 | 22 | # Latex substitutions for escaping latex. |
|
23 | 23 | # see: http://stackoverflow.com/questions/16259923/how-can-i-escape-latex-special-characters-inside-django-templates |
|
24 | ||
|
24 | 25 | LATEX_SUBS = { |
|
25 | 26 | '&': r'\&', |
|
26 |
'%': r'\%', |
|
|
27 |
'$': r'\$', |
|
|
28 |
'#': r'\#', |
|
|
29 |
'_': r'\ |
|
|
30 |
'{': r'\ |
|
|
31 |
'}': r'\ |
|
|
32 |
'~': r'\ |
|
|
33 |
'^': r'\ |
|
|
34 |
'\\': r'\ |
|
|
27 | '%': r'\%', | |
|
28 | '$': r'\$', | |
|
29 | '#': r'\#', | |
|
30 | '_': r'\_', | |
|
31 | '{': r'\{', | |
|
32 | '}': r'\}', | |
|
33 | '~': r'\textasciitilde{}', | |
|
34 | '^': r'\^{}', | |
|
35 | '\\': r'\textbackslash{}', | |
|
36 | } | |
|
35 | 37 | |
|
36 | 38 | |
|
37 | 39 | #----------------------------------------------------------------------------- |
|
38 | 40 | # Functions |
|
39 | 41 | #----------------------------------------------------------------------------- |
|
40 | 42 | |
|
41 | 43 | __all__ = ['escape_latex', |
|
42 | 44 | 'strip_math_space'] |
|
43 | 45 | |
|
44 | 46 | def escape_latex(text): |
|
45 | 47 | """ |
|
46 | 48 | Escape characters that may conflict with latex. |
|
47 | 49 | |
|
48 | 50 | Parameters |
|
49 | 51 | ---------- |
|
50 | 52 | text : str |
|
51 | 53 | Text containing characters that may conflict with Latex |
|
52 | 54 | """ |
|
53 | 55 | |
|
54 | 56 | return ''.join([LATEX_SUBS.get(c, c) for c in text]) |
|
55 | 57 | |
|
56 | 58 | |
|
57 | 59 | def strip_math_space(text): |
|
58 | 60 | """ |
|
59 | 61 | Remove the space between latex math commands and enclosing $ symbols. |
|
60 | 62 | This filter is important because latex isn't as flexible as the notebook |
|
61 | 63 | front end when it comes to flagging math using ampersand symbols. |
|
62 | 64 | |
|
63 | 65 | Parameters |
|
64 | 66 | ---------- |
|
65 | 67 | text : str |
|
66 | 68 | Text to filter. |
|
67 | 69 | """ |
|
68 | 70 | |
|
69 | 71 | # First, scan through the markdown looking for $. If |
|
70 | 72 | # a $ symbol is found, without a preceding \, assume |
|
71 | 73 | # it is the start of a math block. UNLESS that $ is |
|
72 | 74 | # not followed by another within two math_lines. |
|
73 | 75 | math_regions = [] |
|
74 | 76 | math_lines = 0 |
|
75 | 77 | within_math = False |
|
76 | 78 | math_start_index = 0 |
|
77 | 79 | ptext = '' |
|
78 | 80 | last_character = "" |
|
79 | 81 | skip = False |
|
80 | 82 | for index, char in enumerate(text): |
|
81 | 83 | |
|
82 | 84 | #Make sure the character isn't preceeded by a backslash |
|
83 | 85 | if (char == "$" and last_character != "\\"): |
|
84 | 86 | |
|
85 | 87 | # Close the math region if this is an ending $ |
|
86 | 88 | if within_math: |
|
87 | 89 | within_math = False |
|
88 | 90 | skip = True |
|
89 | 91 | ptext = ptext+'$'+text[math_start_index+1:index].strip()+'$' |
|
90 | 92 | math_regions.append([math_start_index, index+1]) |
|
91 | 93 | else: |
|
92 | 94 | |
|
93 | 95 | # Start a new math region |
|
94 | 96 | within_math = True |
|
95 | 97 | math_start_index = index |
|
96 | 98 | math_lines = 0 |
|
97 | 99 | |
|
98 | 100 | # If we are in a math region, count the number of lines parsed. |
|
99 | 101 | # Cancel the math region if we find two line breaks! |
|
100 | 102 | elif char == "\n": |
|
101 | 103 | if within_math: |
|
102 | 104 | math_lines += 1 |
|
103 | 105 | if math_lines > 1: |
|
104 | 106 | within_math = False |
|
105 | 107 | ptext = ptext+text[math_start_index:index] |
|
106 | 108 | |
|
107 | 109 | # Remember the last character so we can easily watch |
|
108 | 110 | # for backslashes |
|
109 | 111 | last_character = char |
|
110 | 112 | if not within_math and not skip: |
|
111 | 113 | ptext = ptext+char |
|
112 | 114 | if skip: |
|
113 | 115 | skip = False |
|
114 | 116 | return ptext |
General Comments 0
You need to be logged in to leave comments.
Login now