/
roff.rb
379 lines (336 loc) · 10.6 KB
/
roff.rb
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
require 'nokogiri'
require 'ronn/utils'
module Ronn
# Filter for converting HTML to ROFF
class RoffFilter
include Ronn::Utils
# Convert Ronn HTML to roff.
# The html input is an HTML fragment, not a complete document
def initialize(html_fragment, name, section, tagline, manual = nil,
version = nil, date = nil)
@buf = []
title_heading name, section, tagline, manual, version, date
doc = Nokogiri::HTML.fragment(html_fragment)
remove_extraneous_elements! doc
normalize_whitespace! doc
block_filter doc
write "\n"
end
def to_s
@buf.join.gsub(/[ \t]+$/, '')
end
protected
def previous(node)
return unless node.respond_to?(:previous)
prev = node.previous
prev = prev.previous until prev.nil? || prev.elem?
prev
end
def title_heading(name, section, _tagline, manual, version, date)
comment "generated with Ronn-NG/v#{Ronn.version}"
comment "http://github.com/apjanke/ronn-ng/tree/#{Ronn.revision}"
return if name.nil?
macro 'TH', %("#{escape(name.upcase)}" "#{section}" "#{date.strftime('%B %Y')}" "#{version}" "#{manual}")
end
def remove_extraneous_elements!(doc)
doc.traverse do |node|
node.parent.children.delete(node) if node.comment?
end
end
def normalize_whitespace!(node)
if node.is_a?(Array) || node.is_a?(Nokogiri::XML::NodeSet)
node.to_a.dup.each { |ch| normalize_whitespace! ch }
elsif node.text?
preceding = node.previous
following = node.next
content = node.content.gsub(/[\n ]+/m, ' ')
if preceding.nil? || block_element?(preceding.name) ||
preceding.name == 'br'
content.lstrip!
end
if following.nil? || block_element?(following.name) ||
following.name == 'br'
content.rstrip!
end
if content.empty?
node.remove
else
node.content = content
end
elsif node.elem? && node.name == 'pre'
# stop traversing
elsif node.elem? && node.children
normalize_whitespace! node.children
elsif node.elem?
# element has no children
elsif node.document? || node.fragment?
normalize_whitespace! node.children
elsif node.is_a?(Nokogiri::XML::DTD) || node.is_a?(Nokogiri::XML::Comment)
# ignore
nop
else
warn 'unexpected node during whitespace normalization: %p', node
end
end
def block_filter(node)
return if node.nil?
if node.is_a?(Array) || node.is_a?(Nokogiri::XML::NodeSet)
node.each { |ch| block_filter(ch) }
elsif node.document? || node.fragment?
block_filter(node.children)
elsif node.text?
# This hack is necessary to support mixed-child-type dd's
inline_filter(node)
elsif node.elem?
case node.name
when 'html', 'body'
block_filter(node.children)
when 'div'
block_filter(node.children)
when 'h1'
# discard
nop
when 'h2'
macro 'SH', quote(escape(node.inner_html))
when 'h3'
macro 'SS', quote(escape(node.inner_html))
when 'p'
prev = previous(node)
if prev && %w[dd li blockquote].include?(node.parent.name)
macro 'IP'
elsif prev && !%w[h1 h2 h3].include?(prev.name)
macro 'P'
elsif node.previous&.text?
macro 'IP'
end
inline_filter(node.children)
when 'blockquote'
prev = previous(node)
indent = prev.nil? || !%w[h1 h2 h3].include?(prev.name)
macro 'IP', %w["" 4] if indent
block_filter(node.children)
macro 'IP', %w["" 0] if indent
when 'pre'
prev = previous(node)
indent = prev.nil? || !%w[h1 h2 h3].include?(prev.name)
macro 'IP', %w["" 4] if indent
macro 'nf'
# HACK: strip an initial \n to avoid extra spacing
if node.children && node.children[0].text?
text = node.children[0].to_s
node.children[0].replace(text[1..-1]) if text.start_with? "\n"
end
inline_filter(node.children)
macro 'fi'
macro 'IP', %w["" 0] if indent
when 'dl'
macro 'TP'
block_filter(node.children)
when 'dt'
prev = previous(node)
macro 'TP' unless prev.nil?
inline_filter(node.children)
write "\n"
when 'dd'
if node.at('p')
block_filter(node.children)
else
inline_filter(node.children)
end
write "\n"
when 'ol', 'ul'
block_filter(node.children)
macro 'IP', %w["" 0]
when 'li'
case node.parent.name
when 'ol'
macro 'IP', %W["#{node.parent.children.index(node) + 1}." 4]
when 'ul'
macro 'IP', ['"\\[ci]"', '4']
else
raise "List element found as a child of non-list parent element: #{node.inspect}"
end
if node.at('p,ol,ul,dl,div')
block_filter(node.children)
else
inline_filter(node.children)
end
write "\n"
when 'span', 'code', 'b', 'strong', 'kbd', 'samp', 'var', 'em', 'i',
'u', 'br', 'a'
inline_filter(node)
when 'table'
macro 'TS'
write "allbox;\n"
block_filter(node.children)
macro 'TE'
when 'thead'
# Convert to format section and first row
tr = node.children[0]
header_contents = []
cell_formats = []
tr.children.each do |th|
style = th['style']
cell_format = case style
when 'text-align:left;'
'l'
when 'text-align:right;'
'r'
when 'text-align:center;'
'c'
else
'l'
end
header_contents << th.inner_html
cell_formats << cell_format
end
write cell_formats.join(' ') + ".\n"
write header_contents.join("\t") + "\n"
when 'th'
raise 'internal error: unexpected <th> element'
when 'tbody'
# Let the 'tr' handle it
block_filter(node.children)
when 'tr'
# Convert to a table data row
node.children.each do |child|
block_filter(child)
write "\t"
end
write "\n"
when 'td'
inline_filter(node.children)
else
warn 'unrecognized block tag: %p', node.name
end
elsif node.is_a?(Nokogiri::XML::DTD)
# Ignore
nop
elsif node.is_a?(Nokogiri::XML::Comment)
# Ignore
nop
else
raise "unexpected node: #{node.inspect}"
end
end
def inline_filter(node)
return unless node # is an empty node
if node.is_a?(Array) || node.is_a?(Nokogiri::XML::NodeSet)
node.each { |ch| inline_filter(ch) }
elsif node.text?
text = node.to_html.dup
write escape(text)
elsif node.elem?
case node.name
when 'span'
inline_filter(node.children)
when 'code'
if child_of?(node, 'pre')
inline_filter(node.children)
else
write '\fB'
inline_filter(node.children)
write '\fR'
end
when 'b', 'strong', 'kbd', 'samp'
write '\fB'
inline_filter(node.children)
write '\fR'
when 'var', 'em', 'i', 'u'
write '\fI'
inline_filter(node.children)
write '\fR'
when 'br'
macro 'br'
when 'a'
if node.classes.include?('man-ref')
inline_filter(node.children)
elsif node.has_attribute?('data-bare-link')
write '\fI'
write '\%' + escape(node.attributes['href'].content)
write '\fR'
else
inline_filter(node.children)
write ' '
write '\fI'
write '\%' + escape(node.attributes['href'].content)
write '\fR'
end
when 'sup'
# This superscript equivalent is a big ugly hack.
write '^('
inline_filter(node.children)
write ')'
else
warn 'unrecognized inline tag: %p', node.name
end
else
raise "unexpected node: #{node.inspect}"
end
end
def maybe_new_line
write "\n" if @buf.last && @buf.last[-1] != "\n"
end
def macro(name, value = nil)
maybe_new_line
writeln ".#{[name, value].compact.join(' ')}"
end
HTML_ROFF_ENTITIES = {
'•' => '\[ci]',
'<' => '<',
'>' => '>',
' ' => '\~', # That's a literal non-breaking space character there
'©' => '\(co',
'”' => '\(rs',
'—' => '\(em',
'®' => '\(rg',
'§' => '\(sc',
'≥' => '\(>=',
'≤' => '\(<=',
'≠' => '\(!=',
'≡' => '\(=='
}.freeze
def escape(text)
return text.to_s if text.nil? || text.empty?
ent = HTML_ROFF_ENTITIES
text = text.dup
text.gsub!(/&#x([0-9A-Fa-f]+);/) { $1.to_i(16).chr } # hex entities
text.gsub!(/&#(\d+);/) { $1.to_i.chr } # dec entities
text.gsub!('\\', '\e') # backslash
text.gsub!('...', '\|.\|.\|.') # ellipses
text.gsub!(/['.-]/) { |m| "\\#{m}" } # control chars
ent.each do |key, val|
text.gsub!(key, val)
end
text.gsub!('&', '&') # amps
text
end
def quote(text)
"\"#{text.gsub(/"/, '\\"')}\""
end
# write text to output buffer
def write(text)
return if text.nil? || text.empty?
# lines cannot start with a '.'. insert zero-width character before.
text = text.gsub(/\n\\\./s, "\n\\\\&\\.")
buf_ends_in_newline = @buf.last && @buf.last[-1] == "\n"
@buf << '\&' if text[0, 2] == '\.' && buf_ends_in_newline
@buf << text
end
# write text to output buffer on a new line.
def writeln(text)
maybe_new_line
write text
write "\n"
end
def comment(text)
writeln %(.\\" #{text})
end
def warn(text, *args)
Kernel.warn format("warn: #{text}", args)
end
def nop
# Do nothing
end
end
end