1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
"""
    pygments.formatters.latex
    ~~~~~~~~~~~~~~~~~~~~~~~~~

    Formatter for LaTeX fancyvrb output.

    :copyright: Copyright 2006-2022 by the Pygments team, see AUTHORS.
    :license: BSD, see LICENSE for details.
"""

from io import StringIO

from pygments.formatter import Formatter
from pygments.lexer import Lexer, do_insertions
from pygments.token import Token, STANDARD_TYPES
from pygments.util import get_bool_opt, get_int_opt


__all__ = ['LatexFormatter']


def escape_tex(text, commandprefix):
    return text.replace('\\', '\x00'). \
                replace('{', '\x01'). \
                replace('}', '\x02'). \
                replace('\x00', r'\%sZbs{}' % commandprefix). \
                replace('\x01', r'\%sZob{}' % commandprefix). \
                replace('\x02', r'\%sZcb{}' % commandprefix). \
                replace('^', r'\%sZca{}' % commandprefix). \
                replace('_', r'\%sZus{}' % commandprefix). \
                replace('&', r'\%sZam{}' % commandprefix). \
                replace('<', r'\%sZlt{}' % commandprefix). \
                replace('>', r'\%sZgt{}' % commandprefix). \
                replace('#', r'\%sZsh{}' % commandprefix). \
                replace('%', r'\%sZpc{}' % commandprefix). \
                replace('$', r'\%sZdl{}' % commandprefix). \
                replace('-', r'\%sZhy{}' % commandprefix). \
                replace("'", r'\%sZsq{}' % commandprefix). \
                replace('"', r'\%sZdq{}' % commandprefix). \
                replace('~', r'\%sZti{}' % commandprefix)


DOC_TEMPLATE = r'''
\documentclass{%(docclass)s}
\usepackage{fancyvrb}
\usepackage{color}
\usepackage[%(encoding)s]{inputenc}
%(preamble)s

%(styledefs)s

\begin{document}

\section*{%(title)s}

%(code)s
\end{document}
'''

## Small explanation of the mess below :)
#
# The previous version of the LaTeX formatter just assigned a command to
# each token type defined in the current style.  That obviously is
# problematic if the highlighted code is produced for a different style
# than the style commands themselves.
#
# This version works much like the HTML formatter which assigns multiple
# CSS classes to each <span> tag, from the most specific to the least
# specific token type, thus falling back to the parent token type if one
# is not defined.  Here, the classes are there too and use the same short
# forms given in token.STANDARD_TYPES.
#
# Highlighted code now only uses one custom command, which by default is
# \PY and selectable by the commandprefix option (and in addition the
# escapes \PYZat, \PYZlb and \PYZrb which haven't been renamed for
# backwards compatibility purposes).
#
# \PY has two arguments: the classes, separated by +, and the text to
# render in that style.  The classes are resolved into the respective
# style commands by magic, which serves to ignore unknown classes.
#
# The magic macros are:
# * \PY@it, \PY@bf, etc. are unconditionally wrapped around the text
#   to render in \PY@do.  Their definition determines the style.
# * \PY@reset resets \PY@it etc. to do nothing.
# * \PY@toks parses the list of classes, using magic inspired by the
#   keyval package (but modified to use plusses instead of commas
#   because fancyvrb redefines commas inside its environments).
# * \PY@tok processes one class, calling the \PY@tok@classname command
#   if it exists.
# * \PY@tok@classname sets the \PY@it etc. to reflect the chosen style
#   for its class.
# * \PY resets the style, parses the classnames and then calls \PY@do.
#
# Tip: to read this code, print it out in substituted form using e.g.
# >>> print STYLE_TEMPLATE % {'cp': 'PY'}

STYLE_TEMPLATE = r'''
\makeatletter
\def\%(cp)s@reset{\let\%(cp)s@it=\relax \let\%(cp)s@bf=\relax%%
    \let\%(cp)s@ul=\relax \let\%(cp)s@tc=\relax%%
    \let\%(cp)s@bc=\relax \let\%(cp)s@ff=\relax}
\def\%(cp)s@tok#1{\csname %(cp)s@tok@#1\endcsname}
\def\%(cp)s@toks#1+{\ifx\relax#1\empty\else%%
    \%(cp)s@tok{#1}\expandafter\%(cp)s@toks\fi}
\def\%(cp)s@do#1{\%(cp)s@bc{\%(cp)s@tc{\%(cp)s@ul{%%
    \%(cp)s@it{\%(cp)s@bf{\%(cp)s@ff{#1}}}}}}}
\def\%(cp)s#1#2{\%(cp)s@reset\%(cp)s@toks#1+\relax+\%(cp)s@do{#2}}

%(styles)s

\def\%(cp)sZbs{\char`\\}
\def\%(cp)sZus{\char`\_}
\def\%(cp)sZob{\char`\{}
\def\%(cp)sZcb{\char`\}}
\def\%(cp)sZca{\char`\^}
\def\%(cp)sZam{\char`\&}
\def\%(cp)sZlt{\char`\<}
\def\%(cp)sZgt{\char`\>}
\def\%(cp)sZsh{\char`\#}
\def\%(cp)sZpc{\char`\%%}
\def\%(cp)sZdl{\char`\$}
\def\%(cp)sZhy{\char`\-}
\def\%(cp)sZsq{\char`\'}
\def\%(cp)sZdq{\char`\"}
\def\%(cp)sZti{\char`\~}
%% for compatibility with earlier versions
\def\%(cp)sZat{@}
\def\%(cp)sZlb{[}
\def\%(cp)sZrb{]}
\makeatother
'''


def _get_ttype_name(ttype):
    fname = STANDARD_TYPES.get(ttype)
    if fname:
        return fname
    aname = ''
    while fname is None:
        aname = ttype[-1] + aname
        ttype = ttype.parent
        fname = STANDARD_TYPES.get(ttype)
    return fname + aname


class LatexFormatter(Formatter):
    r"""
    Format tokens as LaTeX code. This needs the `fancyvrb` and `color`
    standard packages.

    Without the `full` option, code is formatted as one ``Verbatim``
    environment, like this:

    .. sourcecode:: latex

        \begin{Verbatim}[commandchars=\\\{\}]
        \PY{k}{def }\PY{n+nf}{foo}(\PY{n}{bar}):
            \PY{k}{pass}
        \end{Verbatim}

    Wrapping can be disabled using the `nowrap` option.

    The special command used here (``\PY``) and all the other macros it needs
    are output by the `get_style_defs` method.

    With the `full` option, a complete LaTeX document is output, including
    the command definitions in the preamble.

    The `get_style_defs()` method of a `LatexFormatter` returns a string
    containing ``\def`` commands defining the macros needed inside the
    ``Verbatim`` environments.

    Additional options accepted:

    `nowrap`
        If set to ``True``, don't wrap the tokens at all, not even inside a
        ``\begin{Verbatim}`` environment. This disables most other options
        (default: ``False``).

    `style`
        The style to use, can be a string or a Style subclass (default:
        ``'default'``).

    `full`
        Tells the formatter to output a "full" document, i.e. a complete
        self-contained document (default: ``False``).

    `title`
        If `full` is true, the title that should be used to caption the
        document (default: ``''``).

    `docclass`
        If the `full` option is enabled, this is the document class to use
        (default: ``'article'``).

    `preamble`
        If the `full` option is enabled, this can be further preamble commands,
        e.g. ``\usepackage`` (default: ``''``).

    `linenos`
        If set to ``True``, output line numbers (default: ``False``).

    `linenostart`
        The line number for the first line (default: ``1``).

    `linenostep`
        If set to a number n > 1, only every nth line number is printed.

    `verboptions`
        Additional options given to the Verbatim environment (see the *fancyvrb*
        docs for possible values) (default: ``''``).

    `commandprefix`
        The LaTeX commands used to produce colored output are constructed
        using this prefix and some letters (default: ``'PY'``).

        .. versionadded:: 0.7
        .. versionchanged:: 0.10
           The default is now ``'PY'`` instead of ``'C'``.

    `texcomments`
        If set to ``True``, enables LaTeX comment lines.  That is, LaTex markup
        in comment tokens is not escaped so that LaTeX can render it (default:
        ``False``).

        .. versionadded:: 1.2

    `mathescape`
        If set to ``True``, enables LaTeX math mode escape in comments. That
        is, ``'$...$'`` inside a comment will trigger math mode (default:
        ``False``).

        .. versionadded:: 1.2

    `escapeinside`
        If set to a string of length 2, enables escaping to LaTeX. Text
        delimited by these 2 characters is read as LaTeX code and
        typeset accordingly. It has no effect in string literals. It has
        no effect in comments if `texcomments` or `mathescape` is
        set. (default: ``''``).

        .. versionadded:: 2.0

    `envname`
        Allows you to pick an alternative environment name replacing Verbatim.
        The alternate environment still has to support Verbatim's option syntax.
        (default: ``'Verbatim'``).

        .. versionadded:: 2.0
    """
    name = 'LaTeX'
    aliases = ['latex', 'tex']
    filenames = ['*.tex']

    def __init__(self, **options):
        Formatter.__init__(self, **options)
        self.nowrap = get_bool_opt(options, 'nowrap', False)
        self.docclass = options.get('docclass', 'article')
        self.preamble = options.get('preamble', '')
        self.linenos = get_bool_opt(options, 'linenos', False)
        self.linenostart = abs(get_int_opt(options, 'linenostart', 1))
        self.linenostep = abs(get_int_opt(options, 'linenostep', 1))
        self.verboptions = options.get('verboptions', '')
        self.nobackground = get_bool_opt(options, 'nobackground', False)
        self.commandprefix = options.get('commandprefix', 'PY')
        self.texcomments = get_bool_opt(options, 'texcomments', False)
        self.mathescape = get_bool_opt(options, 'mathescape', False)
        self.escapeinside = options.get('escapeinside', '')
        if len(self.escapeinside) == 2:
            self.left = self.escapeinside[0]
            self.right = self.escapeinside[1]
        else:
            self.escapeinside = ''
        self.envname = options.get('envname', 'Verbatim')

        self._create_stylesheet()

    def _create_stylesheet(self):
        t2n = self.ttype2name = {Token: ''}
        c2d = self.cmd2def = {}
        cp = self.commandprefix

        def rgbcolor(col):
            if col:
                return ','.join(['%.2f' % (int(col[i] + col[i + 1], 16) / 255.0)
                                 for i in (0, 2, 4)])
            else:
                return '1,1,1'

        for ttype, ndef in self.style:
            name = _get_ttype_name(ttype)
            cmndef = ''
            if ndef['bold']:
                cmndef += r'\let\$$@bf=\textbf'
            if ndef['italic']:
                cmndef += r'\let\$$@it=\textit'
            if ndef['underline']:
                cmndef += r'\let\$$@ul=\underline'
            if ndef['roman']:
                cmndef += r'\let\$$@ff=\textrm'
            if ndef['sans']:
                cmndef += r'\let\$$@ff=\textsf'
            if ndef['mono']:
                cmndef += r'\let\$$@ff=\textsf'
            if ndef['color']:
                cmndef += (r'\def\$$@tc##1{\textcolor[rgb]{%s}{##1}}' %
                           rgbcolor(ndef['color']))
            if ndef['border']:
                cmndef += (r'\def\$$@bc##1{{\setlength{\fboxsep}{\string -\fboxrule}'
                           r'\fcolorbox[rgb]{%s}{%s}{\strut ##1}}}' %
                           (rgbcolor(ndef['border']),
                            rgbcolor(ndef['bgcolor'])))
            elif ndef['bgcolor']:
                cmndef += (r'\def\$$@bc##1{{\setlength{\fboxsep}{0pt}'
                           r'\colorbox[rgb]{%s}{\strut ##1}}}' %
                           rgbcolor(ndef['bgcolor']))
            if cmndef == '':
                continue
            cmndef = cmndef.replace('$$', cp)
            t2n[ttype] = name
            c2d[name] = cmndef

    def get_style_defs(self, arg=''):
        """
        Return the command sequences needed to define the commands
        used to format text in the verbatim environment. ``arg`` is ignored.
        """
        cp = self.commandprefix
        styles = []
        for name, definition in self.cmd2def.items():
            styles.append(r'\@namedef{%s@tok@%s}{%s}' % (cp, name, definition))
        return STYLE_TEMPLATE % {'cp': self.commandprefix,
                                 'styles': '\n'.join(styles)}

    def format_unencoded(self, tokensource, outfile):
        # TODO: add support for background colors
        t2n = self.ttype2name
        cp = self.commandprefix

        if self.full:
            realoutfile = outfile
            outfile = StringIO()

        if not self.nowrap:
            outfile.write('\\begin{' + self.envname + '}[commandchars=\\\\\\{\\}')
            if self.linenos:
                start, step = self.linenostart, self.linenostep
                outfile.write(',numbers=left' +
                              (start and ',firstnumber=%d' % start or '') +
                              (step and ',stepnumber=%d' % step or ''))
            if self.mathescape or self.texcomments or self.escapeinside:
                outfile.write(',codes={\\catcode`\\$=3\\catcode`\\^=7'
                              '\\catcode`\\_=8\\relax}')
            if self.verboptions:
                outfile.write(',' + self.verboptions)
            outfile.write(']\n')

        for ttype, value in tokensource:
            if ttype in Token.Comment:
                if self.texcomments:
                    # Try to guess comment starting lexeme and escape it ...
                    start = value[0:1]
                    for i in range(1, len(value)):
                        if start[0] != value[i]:
                            break
                        start += value[i]

                    value = value[len(start):]
                    start = escape_tex(start, cp)

                    # ... but do not escape inside comment.
                    value = start + value
                elif self.mathescape:
                    # Only escape parts not inside a math environment.
                    parts = value.split('$')
                    in_math = False
                    for i, part in enumerate(parts):
                        if not in_math:
                            parts[i] = escape_tex(part, cp)
                        in_math = not in_math
                    value = '$'.join(parts)
                elif self.escapeinside:
                    text = value
                    value = ''
                    while text:
                        a, sep1, text = text.partition(self.left)
                        if sep1:
                            b, sep2, text = text.partition(self.right)
                            if sep2:
                                value += escape_tex(a, cp) + b
                            else:
                                value += escape_tex(a + sep1 + b, cp)
                        else:
                            value += escape_tex(a, cp)
                else:
                    value = escape_tex(value, cp)
            elif ttype not in Token.Escape:
                value = escape_tex(value, cp)
            styles = []
            while ttype is not Token:
                try:
                    styles.append(t2n[ttype])
                except KeyError:
                    # not in current style
                    styles.append(_get_ttype_name(ttype))
                ttype = ttype.parent
            styleval = '+'.join(reversed(styles))
            if styleval:
                spl = value.split('\n')
                for line in spl[:-1]:
                    if line:
                        outfile.write("\\%s{%s}{%s}" % (cp, styleval, line))
                    outfile.write('\n')
                if spl[-1]:
                    outfile.write("\\%s{%s}{%s}" % (cp, styleval, spl[-1]))
            else:
                outfile.write(value)

        if not self.nowrap:
            outfile.write('\\end{' + self.envname + '}\n')

        if self.full:
            encoding = self.encoding or 'utf8'
            # map known existings encodings from LaTeX distribution
            encoding = {
                'utf_8': 'utf8',
                'latin_1': 'latin1',
                'iso_8859_1': 'latin1',
            }.get(encoding.replace('-', '_'), encoding)
            realoutfile.write(DOC_TEMPLATE %
                dict(docclass  = self.docclass,
                     preamble  = self.preamble,
                     title     = self.title,
                     encoding  = encoding,
                     styledefs = self.get_style_defs(),
                     code      = outfile.getvalue()))


class LatexEmbeddedLexer(Lexer):
    """
    This lexer takes one lexer as argument, the lexer for the language
    being formatted, and the left and right delimiters for escaped text.

    First everything is scanned using the language lexer to obtain
    strings and comments. All other consecutive tokens are merged and
    the resulting text is scanned for escaped segments, which are given
    the Token.Escape type. Finally text that is not escaped is scanned
    again with the language lexer.
    """
    def __init__(self, left, right, lang, **options):
        self.left = left
        self.right = right
        self.lang = lang
        Lexer.__init__(self, **options)

    def get_tokens_unprocessed(self, text):
        # find and remove all the escape tokens (replace with an empty string)
        # this is very similar to DelegatingLexer.get_tokens_unprocessed.
        buffered = ''
        insertions = []
        insertion_buf = []
        for i, t, v in self._find_safe_escape_tokens(text):
            if t is None:
                if insertion_buf:
                    insertions.append((len(buffered), insertion_buf))
                    insertion_buf = []
                buffered += v
            else:
                insertion_buf.append((i, t, v))
        if insertion_buf:
            insertions.append((len(buffered), insertion_buf))
        return do_insertions(insertions,
                             self.lang.get_tokens_unprocessed(buffered))

    def _find_safe_escape_tokens(self, text):
        """ find escape tokens that are not in strings or comments """
        for i, t, v in self._filter_to(
            self.lang.get_tokens_unprocessed(text),
            lambda t: t in Token.Comment or t in Token.String
        ):
            if t is None:
                for i2, t2, v2 in self._find_escape_tokens(v):
                    yield i + i2, t2, v2
            else:
                yield i, None, v

    def _filter_to(self, it, pred):
        """ Keep only the tokens that match `pred`, merge the others together """
        buf = ''
        idx = 0
        for i, t, v in it:
            if pred(t):
                if buf:
                    yield idx, None, buf
                    buf = ''
                yield i, t, v
            else:
                if not buf:
                    idx = i
                buf += v
        if buf:
            yield idx, None, buf

    def _find_escape_tokens(self, text):
        """ Find escape tokens within text, give token=None otherwise """
        index = 0
        while text:
            a, sep1, text = text.partition(self.left)
            if a:
                yield index, None, a
                index += len(a)
            if sep1:
                b, sep2, text = text.partition(self.right)
                if sep2:
                    yield index + len(sep1), Token.Escape, b
                    index += len(sep1) + len(b) + len(sep2)
                else:
                    yield index, Token.Error, sep1
                    index += len(sep1)
                    text = b