aboutsummaryrefslogtreecommitdiff
path: root/src/Text/Pandoc/Extensions.hs
blob: 771898d70afb6ba662115571fddae45acaacbb8f (plain)
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
{-
Copyright (C) 2012-2017 John MacFarlane <jgm@berkeley.edu>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-}
{-# LANGUAGE DeriveDataTypeable         #-}
{-# LANGUAGE DeriveGeneric              #-}
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE TemplateHaskell            #-}

{- |
   Module      : Text.Pandoc.Extensions
   Copyright   : Copyright (C) 2012-2017 John MacFarlane
   License     : GNU GPL, version 2 or above

   Maintainer  : John MacFarlane <jgm@berkeley.edu>
   Stability   : alpha
   Portability : portable

Data structures and functions for representing markup extensions.
-}
module Text.Pandoc.Extensions ( Extension(..)
                              , Extensions
                              , emptyExtensions
                              , extensionsFromList
                              , parseFormatSpec
                              , extensionEnabled
                              , enableExtension
                              , disableExtension
                              , getDefaultExtensions
                              , pandocExtensions
                              , plainExtensions
                              , strictExtensions
                              , phpMarkdownExtraExtensions
                              , githubMarkdownExtensions
                              , multimarkdownExtensions )
where
import Data.Aeson (FromJSON (..), ToJSON (..), defaultOptions)
import Data.Aeson.TH (deriveJSON)
import Data.Bits (clearBit, setBit, testBit, (.|.))
import Data.Data (Data)
import Data.Typeable (Typeable)
import GHC.Generics (Generic)
import Text.Pandoc.Shared (safeRead)
import Text.Parsec

newtype Extensions = Extensions Integer
  deriving (Show, Read, Eq, Ord, Data, Typeable, Generic, ToJSON, FromJSON)

instance Monoid Extensions where
  mempty = Extensions 0
  mappend (Extensions a) (Extensions b) = Extensions (a .|. b)

extensionsFromList :: [Extension] -> Extensions
extensionsFromList = foldr enableExtension emptyExtensions

emptyExtensions :: Extensions
emptyExtensions = Extensions 0

extensionEnabled :: Extension -> Extensions -> Bool
extensionEnabled x (Extensions exts) = testBit exts (fromEnum x)

enableExtension :: Extension -> Extensions -> Extensions
enableExtension x (Extensions exts) = Extensions (setBit exts (fromEnum x))

disableExtension :: Extension -> Extensions -> Extensions
disableExtension x (Extensions exts) = Extensions (clearBit exts (fromEnum x))

-- | Individually selectable syntax extensions.
data Extension =
      Ext_footnotes           -- ^ Pandoc/PHP/MMD style footnotes
    | Ext_inline_notes        -- ^ Pandoc-style inline notes
    | Ext_pandoc_title_block  -- ^ Pandoc title block
    | Ext_yaml_metadata_block -- ^ YAML metadata block
    | Ext_mmd_title_block     -- ^ Multimarkdown metadata block
    | Ext_table_captions      -- ^ Pandoc-style table captions
    | Ext_implicit_figures    -- ^ A paragraph with just an image is a figure
    | Ext_simple_tables       -- ^ Pandoc-style simple tables
    | Ext_multiline_tables    -- ^ Pandoc-style multiline tables
    | Ext_grid_tables         -- ^ Grid tables (pandoc, reST)
    | Ext_pipe_tables         -- ^ Pipe tables (as in PHP markdown extra)
    | Ext_citations           -- ^ Pandoc/citeproc citations
    | Ext_raw_tex             -- ^ Allow raw TeX (other than math)
    | Ext_raw_html            -- ^ Allow raw HTML
    | Ext_tex_math_dollars    -- ^ TeX math between $..$ or $$..$$
    | Ext_tex_math_single_backslash  -- ^ TeX math btw \(..\) \[..\]
    | Ext_tex_math_double_backslash  -- ^ TeX math btw \\(..\\) \\[..\\]
    | Ext_latex_macros        -- ^ Parse LaTeX macro definitions (for math only)
    | Ext_fenced_code_blocks  -- ^ Parse fenced code blocks
    | Ext_fenced_code_attributes  -- ^ Allow attributes on fenced code blocks
    | Ext_backtick_code_blocks    -- ^ GitHub style ``` code blocks
    | Ext_inline_code_attributes  -- ^ Allow attributes on inline code
    | Ext_raw_attribute           -- ^ Allow explicit raw blocks/inlines
    | Ext_markdown_in_html_blocks -- ^ Interpret as markdown inside HTML blocks
    | Ext_native_divs             -- ^ Use Div blocks for contents of <div> tags
    | Ext_fenced_divs             -- ^ Allow fenced div syntax :::
    | Ext_native_spans            -- ^ Use Span inlines for contents of <span>
    | Ext_bracketed_spans         -- ^ Bracketed spans with attributes
    | Ext_markdown_attribute      -- ^ Interpret text inside HTML as markdown
                                  --   iff container has attribute 'markdown'
    | Ext_escaped_line_breaks     -- ^ Treat a backslash at EOL as linebreak
    | Ext_link_attributes         -- ^ link and image attributes
    | Ext_mmd_link_attributes     -- ^ MMD style reference link attributes
    | Ext_autolink_bare_uris  -- ^ Make all absolute URIs into links
    | Ext_fancy_lists         -- ^ Enable fancy list numbers and delimiters
    | Ext_lists_without_preceding_blankline -- ^ Allow lists without preceding blank
    | Ext_four_space_rule     -- ^ Require 4-space indent for list contents
    | Ext_startnum            -- ^ Make start number of ordered list significant
    | Ext_definition_lists    -- ^ Definition lists as in pandoc, mmd, php
    | Ext_compact_definition_lists  -- ^ Definition lists without
                               -- space between items, and disallow laziness
    | Ext_example_lists       -- ^ Markdown-style numbered examples
    | Ext_all_symbols_escapable  -- ^ Make all non-alphanumerics escapable
    | Ext_angle_brackets_escapable  -- ^ Make < and > escapable
    | Ext_intraword_underscores  -- ^ Treat underscore inside word as literal
    | Ext_blank_before_blockquote -- ^ Require blank line before a blockquote
    | Ext_blank_before_header     -- ^ Require blank line before a header
    | Ext_space_in_atx_header -- ^ Require space between # and header text
    | Ext_strikeout           -- ^ Strikeout using ~~this~~ syntax
    | Ext_superscript         -- ^ Superscript using ^this^ syntax
    | Ext_subscript           -- ^ Subscript using ~this~ syntax
    | Ext_hard_line_breaks    -- ^ All newlines become hard line breaks
    | Ext_ignore_line_breaks  -- ^ Newlines in paragraphs are ignored
    | Ext_east_asian_line_breaks  -- ^ Newlines in paragraphs are ignored between
                              -- East Asian wide characters
    | Ext_literate_haskell    -- ^ Enable literate Haskell conventions
    | Ext_abbreviations       -- ^ PHP markdown extra abbreviation definitions
    | Ext_emoji               -- ^ Support emoji like :smile:
    | Ext_auto_identifiers    -- ^ Automatic identifiers for headers
    | Ext_gfm_auto_identifiers  -- ^ Automatic identifiers for headers,
                                -- using GitHub's method for generating identifiers
    | Ext_ascii_identifiers   -- ^ ascii-only identifiers for headers
    | Ext_header_attributes   -- ^ Explicit header attributes {#id .class k=v}
    | Ext_mmd_header_identifiers -- ^ Multimarkdown style header identifiers [myid]
    | Ext_implicit_header_references -- ^ Implicit reference links for headers
    | Ext_line_blocks         -- ^ RST style line blocks
    | Ext_epub_html_exts      -- ^ Recognise the EPUB extended version of HTML
    | Ext_shortcut_reference_links -- ^ Shortcut reference links
    | Ext_smart               -- ^ "Smart" quotes, apostrophes, ellipses, dashes
    | Ext_old_dashes          -- ^ -- = em, - before number = en
    | Ext_spaced_reference_links -- ^ Allow space between two parts of ref link
    | Ext_amuse -- ^ Enable Text::Amuse extensions to Emacs Muse markup
    | Ext_empty_paragraphs -- ^ Allow empty paragraphs
    deriving (Show, Read, Enum, Eq, Ord, Bounded, Data, Typeable, Generic)

-- | Extensions to be used with pandoc-flavored markdown.
pandocExtensions :: Extensions
pandocExtensions = extensionsFromList
  [ Ext_footnotes
  , Ext_inline_notes
  , Ext_pandoc_title_block
  , Ext_yaml_metadata_block
  , Ext_table_captions
  , Ext_implicit_figures
  , Ext_simple_tables
  , Ext_multiline_tables
  , Ext_grid_tables
  , Ext_pipe_tables
  , Ext_citations
  , Ext_raw_tex
  , Ext_raw_html
  , Ext_tex_math_dollars
  , Ext_latex_macros
  , Ext_fenced_code_blocks
  , Ext_fenced_code_attributes
  , Ext_backtick_code_blocks
  , Ext_inline_code_attributes
  , Ext_raw_attribute
  , Ext_markdown_in_html_blocks
  , Ext_native_divs
  , Ext_fenced_divs
  , Ext_native_spans
  , Ext_bracketed_spans
  , Ext_escaped_line_breaks
  , Ext_fancy_lists
  , Ext_startnum
  , Ext_definition_lists
  , Ext_example_lists
  , Ext_all_symbols_escapable
  , Ext_intraword_underscores
  , Ext_blank_before_blockquote
  , Ext_blank_before_header
  , Ext_space_in_atx_header
  , Ext_strikeout
  , Ext_superscript
  , Ext_subscript
  , Ext_auto_identifiers
  , Ext_header_attributes
  , Ext_link_attributes
  , Ext_implicit_header_references
  , Ext_line_blocks
  , Ext_shortcut_reference_links
  , Ext_smart
  ]

-- | Extensions to be used with plain text output.
plainExtensions :: Extensions
plainExtensions = extensionsFromList
  [ Ext_table_captions
  , Ext_implicit_figures
  , Ext_simple_tables
  , Ext_multiline_tables
  , Ext_grid_tables
  , Ext_latex_macros
  , Ext_fancy_lists
  , Ext_startnum
  , Ext_definition_lists
  , Ext_example_lists
  , Ext_intraword_underscores
  , Ext_blank_before_blockquote
  , Ext_blank_before_header
  , Ext_strikeout
  ]

-- | Extensions to be used with github-flavored markdown.
phpMarkdownExtraExtensions :: Extensions
phpMarkdownExtraExtensions = extensionsFromList
  [ Ext_footnotes
  , Ext_pipe_tables
  , Ext_raw_html
  , Ext_markdown_attribute
  , Ext_fenced_code_blocks
  , Ext_definition_lists
  , Ext_intraword_underscores
  , Ext_header_attributes
  , Ext_link_attributes
  , Ext_abbreviations
  , Ext_shortcut_reference_links
  , Ext_spaced_reference_links
  ]

-- | Extensions to be used with github-flavored markdown.
githubMarkdownExtensions :: Extensions
githubMarkdownExtensions = extensionsFromList
  [ Ext_angle_brackets_escapable
  , Ext_pipe_tables
  , Ext_raw_html
  , Ext_fenced_code_blocks
  , Ext_gfm_auto_identifiers
  , Ext_ascii_identifiers
  , Ext_backtick_code_blocks
  , Ext_autolink_bare_uris
  , Ext_space_in_atx_header
  , Ext_intraword_underscores
  , Ext_strikeout
  , Ext_emoji
  , Ext_lists_without_preceding_blankline
  , Ext_shortcut_reference_links
  ]

-- | Extensions to be used with multimarkdown.
multimarkdownExtensions :: Extensions
multimarkdownExtensions = extensionsFromList
  [ Ext_pipe_tables
  , Ext_raw_html
  , Ext_markdown_attribute
  , Ext_mmd_link_attributes
  -- , Ext_raw_tex
  -- Note: MMD's raw TeX syntax requires raw TeX to be
  -- enclosed in HTML comment
  , Ext_tex_math_double_backslash
  , Ext_intraword_underscores
  , Ext_mmd_title_block
  , Ext_footnotes
  , Ext_definition_lists
  , Ext_all_symbols_escapable
  , Ext_implicit_header_references
  , Ext_shortcut_reference_links
  , Ext_auto_identifiers
  , Ext_mmd_header_identifiers
  , Ext_implicit_figures
  -- Note: MMD's syntax for superscripts and subscripts
  -- is a bit more permissive than pandoc's, allowing
  -- e^2 and a~1 instead of e^2^ and a~1~, so even with
  -- these options we don't have full support for MMD
  -- superscripts and subscripts, but there's no reason
  -- not to include these:
  , Ext_superscript
  , Ext_subscript
  , Ext_backtick_code_blocks
  , Ext_spaced_reference_links
  -- So far only in dev version of mmd:
  , Ext_raw_attribute
  ]

-- | Language extensions to be used with strict markdown.
strictExtensions :: Extensions
strictExtensions = extensionsFromList
  [ Ext_raw_html
  , Ext_shortcut_reference_links
  , Ext_spaced_reference_links
  ]

-- | Default extensions from format-describing string.
getDefaultExtensions :: String -> Extensions
getDefaultExtensions "markdown_strict" = strictExtensions
getDefaultExtensions "markdown_phpextra" = phpMarkdownExtraExtensions
getDefaultExtensions "markdown_mmd" = multimarkdownExtensions
getDefaultExtensions "markdown_github" = githubMarkdownExtensions
getDefaultExtensions "markdown"        = pandocExtensions
getDefaultExtensions "muse"            = extensionsFromList
                                           [Ext_amuse,
                                            Ext_auto_identifiers]
getDefaultExtensions "plain"           = plainExtensions
getDefaultExtensions "gfm"             = githubMarkdownExtensions
getDefaultExtensions "org"             = extensionsFromList
                                          [Ext_citations,
                                           Ext_auto_identifiers]
getDefaultExtensions "html"            = extensionsFromList
                                          [Ext_auto_identifiers,
                                           Ext_native_divs,
                                           Ext_native_spans]
getDefaultExtensions "html4"           = getDefaultExtensions "html"
getDefaultExtensions "html5"           = getDefaultExtensions "html"
getDefaultExtensions "epub"            = extensionsFromList
                                          [Ext_raw_html,
                                           Ext_native_divs,
                                           Ext_native_spans,
                                           Ext_epub_html_exts]
getDefaultExtensions "epub2"           = getDefaultExtensions "epub"
getDefaultExtensions "epub3"           = getDefaultExtensions "epub"
getDefaultExtensions "latex"           = extensionsFromList
                                          [Ext_smart,
                                           Ext_latex_macros,
                                           Ext_auto_identifiers]
getDefaultExtensions "context"         = extensionsFromList
                                          [Ext_smart,
                                           Ext_auto_identifiers]
getDefaultExtensions "textile"         = extensionsFromList
                                          [Ext_old_dashes,
                                           Ext_smart,
                                           Ext_raw_html,
                                           Ext_auto_identifiers]
getDefaultExtensions _                 = extensionsFromList
                                          [Ext_auto_identifiers]

-- | Parse a format-specifying string into a markup format and a function that
-- takes Extensions and enables and disables extensions as defined in the format
-- spec.
parseFormatSpec :: String
                -> Either ParseError (String, Extensions -> Extensions)
parseFormatSpec = parse formatSpec ""
  where formatSpec = do
          name <- formatName
          extMods <- many extMod
          return (name, \x -> foldl (flip ($)) x extMods)
        formatName = many1 $ noneOf "-+"
        extMod = do
          polarity <- oneOf "-+"
          name <- many $ noneOf "-+"
          ext <- case safeRead ("Ext_" ++ name) of
                       Just n  -> return n
                       Nothing
                         | name == "lhs" -> return Ext_literate_haskell
                         | otherwise -> fail $ "Unknown extension: " ++ name
          return $ case polarity of
                        '-' -> disableExtension ext
                        _   -> enableExtension ext

$(deriveJSON defaultOptions ''Extension)