rf-web/vendor/bundle/gems/kramdown-2.1.0/lib/kramdown/converter/latex.rb
2019-10-21 10:18:17 +02:00

626 lines
19 KiB
Ruby

# -*- coding: utf-8; frozen_string_literal: true -*-
#
#--
# Copyright (C) 2009-2019 Thomas Leitner <t_leitner@gmx.at>
#
# This file is part of kramdown which is licensed under the MIT.
#++
#
require 'set'
require 'kramdown/converter'
module Kramdown
module Converter
# Converts an element tree to LaTeX.
#
# This converter uses ideas from other Markdown-to-LaTeX converters like Pandoc and Maruku.
#
# You can customize this converter by sub-classing it and overriding the +convert_NAME+ methods.
# Each such method takes the following parameters:
#
# [+el+] The element of type +NAME+ to be converted.
#
# [+opts+] A hash containing processing options that are passed down from parent elements. The
# key :parent is always set and contains the parent element as value.
#
# The return value of such a method has to be a string containing the element +el+ formatted
# correctly as LaTeX markup.
class Latex < Base
# Initialize the LaTeX converter with the +root+ element and the conversion +options+.
def initialize(root, options)
super
@data[:packages] = Set.new
end
# Dispatch the conversion of the element +el+ to a +convert_TYPE+ method using the +type+ of
# the element.
def convert(el, opts = {})
send("convert_#{el.type}", el, opts)
end
# Return the converted content of the children of +el+ as a string.
def inner(el, opts)
result = +''
options = opts.dup.merge(parent: el)
el.children.each_with_index do |inner_el, index|
options[:index] = index
options[:result] = result
result << send("convert_#{inner_el.type}", inner_el, options)
end
result
end
def convert_root(el, opts)
inner(el, opts)
end
def convert_blank(_el, opts)
opts[:result] =~ /\n\n\Z|\A\Z/ ? "" : "\n"
end
def convert_text(el, _opts)
escape(el.value)
end
def convert_p(el, opts)
if el.children.size == 1 && el.children.first.type == :img &&
!(img = convert_img(el.children.first, opts)).empty?
convert_standalone_image(el, opts, img)
else
"#{latex_link_target(el)}#{inner(el, opts)}\n\n"
end
end
# Helper method used by +convert_p+ to convert a paragraph that only contains a single :img
# element.
def convert_standalone_image(el, _opts, img)
attrs = attribute_list(el)
"\\begin{figure}#{attrs}\n\\begin{center}\n#{img}\n\\end{center}\n" \
"\\caption{#{escape(el.children.first.attr['alt'])}}\n" \
"#{latex_link_target(el, true)}\n\\end{figure}#{attrs}\n"
end
def convert_codeblock(el, _opts)
show_whitespace = el.attr['class'].to_s =~ /\bshow-whitespaces\b/
lang = extract_code_language(el.attr)
if @options[:syntax_highlighter] == :minted &&
(highlighted_code = highlight_code(el.value, lang, :block))
@data[:packages] << 'minted'
"#{latex_link_target(el)}#{highlighted_code}\n"
elsif show_whitespace || lang
options = []
options << (show_whitespace ? "showspaces=true,showtabs=true" : "showspaces=false,showtabs=false")
options << "language=#{lang}" if lang
options << "basicstyle=\\ttfamily\\footnotesize,columns=fixed,frame=tlbr"
id = el.attr['id']
options << "label=#{id}" if id
attrs = attribute_list(el)
"#{latex_link_target(el)}\\begin{lstlisting}[#{options.join(',')}]\n" \
"#{el.value}\n\\end{lstlisting}#{attrs}\n"
else
"#{latex_link_target(el)}\\begin{verbatim}#{el.value}\\end{verbatim}\n"
end
end
def convert_blockquote(el, opts)
latex_environment(el.children.size > 1 ? 'quotation' : 'quote', el, inner(el, opts))
end
def convert_header(el, opts)
type = @options[:latex_headers][output_header_level(el.options[:level]) - 1]
if ((id = el.attr['id']) ||
(@options[:auto_ids] && (id = generate_id(el.options[:raw_text])))) && in_toc?(el)
"\\#{type}{#{inner(el, opts)}}\\hypertarget{#{id}}{}\\label{#{id}}\n\n"
else
"\\#{type}*{#{inner(el, opts)}}\n\n"
end
end
def convert_hr(el, _opts)
attrs = attribute_list(el)
"#{latex_link_target(el)}\\begin{center}#{attrs}\n\\rule{3in}{0.4pt}\n\\end{center}#{attrs}\n"
end
def convert_ul(el, opts)
if !@data[:has_toc] && (el.options[:ial][:refs].include?('toc') rescue nil)
@data[:has_toc] = true
'\tableofcontents'
else
latex_environment(el.type == :ul ? 'itemize' : 'enumerate', el, inner(el, opts))
end
end
alias convert_ol convert_ul
def convert_dl(el, opts)
latex_environment('description', el, inner(el, opts))
end
def convert_li(el, opts)
"\\item{} #{latex_link_target(el, true)}#{inner(el, opts).sub(/\n+\Z/, '')}\n"
end
def convert_dt(el, opts)
"\\item[#{inner(el, opts)}] "
end
def convert_dd(el, opts)
"#{latex_link_target(el)}#{inner(el, opts)}\n\n"
end
def convert_html_element(el, opts)
if el.value == 'i' || el.value == 'em'
"\\emph{#{inner(el, opts)}}"
elsif el.value == 'b' || el.value == 'strong'
"\\textbf{#{inner(el, opts)}}"
else
warning("Can't convert HTML element")
''
end
end
def convert_xml_comment(el, _opts)
el.value.split(/\n/).map {|l| "% #{l}" }.join("\n") + "\n"
end
def convert_xml_pi(_el, _opts)
warning("Can't convert XML PI")
''
end
TABLE_ALIGNMENT_CHAR = {default: 'l', left: 'l', center: 'c', right: 'r'} # :nodoc:
def convert_table(el, opts)
@data[:packages] << 'longtable'
align = el.options[:alignment].map {|a| TABLE_ALIGNMENT_CHAR[a] }.join('|')
attrs = attribute_list(el)
"#{latex_link_target(el)}\\begin{longtable}{|#{align}|}#{attrs}\n" \
"\\hline\n#{inner(el, opts)}\\hline\n\\end{longtable}#{attrs}\n\n"
end
def convert_thead(el, opts)
"#{inner(el, opts)}\\hline\n"
end
def convert_tbody(el, opts)
inner(el, opts)
end
def convert_tfoot(el, opts)
"\\hline \\hline \n#{inner(el, opts)}"
end
def convert_tr(el, opts)
el.children.map {|c| send("convert_#{c.type}", c, opts) }.join(' & ') << "\\\\\n"
end
def convert_td(el, opts)
inner(el, opts)
end
def convert_comment(el, _opts)
el.value.split(/\n/).map {|l| "% #{l}" }.join("\n") << "\n"
end
def convert_br(_el, opts)
res = +"\\newline"
res << "\n" if (c = opts[:parent].children[opts[:index] + 1]) &&
(c.type != :text || c.value !~ /^\s*\n/)
res
end
def convert_a(el, opts)
url = el.attr['href']
if url.start_with?('#')
"\\hyperlink{#{url[1..-1].gsub('%', '\\%')}}{#{inner(el, opts)}}"
else
"\\href{#{url.gsub('%', '\\%')}}{#{inner(el, opts)}}"
end
end
def convert_img(el, _opts)
line = el.options[:location]
if el.attr['src'] =~ /^(https?|ftps?):\/\//
warning("Cannot include non-local image#{line ? " (line #{line})" : ''}")
''
elsif !el.attr['src'].empty?
@data[:packages] << 'graphicx'
"#{latex_link_target(el)}\\includegraphics{#{el.attr['src']}}"
else
warning("Cannot include image with empty path#{line ? " (line #{line})" : ''}")
''
end
end
def convert_codespan(el, _opts)
lang = extract_code_language(el.attr)
if @options[:syntax_highlighter] == :minted &&
(highlighted_code = highlight_code(el.value, lang, :span))
@data[:packages] << 'minted'
"#{latex_link_target(el)}#{highlighted_code}"
else
"\\texttt{#{latex_link_target(el)}#{escape(el.value)}}"
end
end
def convert_footnote(el, opts)
@data[:packages] << 'fancyvrb'
"\\footnote{#{inner(el.value, opts).rstrip}}"
end
def convert_raw(el, _opts)
if !el.options[:type] || el.options[:type].empty? || el.options[:type].include?('latex')
el.value + (el.options[:category] == :block ? "\n" : '')
else
''
end
end
def convert_em(el, opts)
"\\emph{#{latex_link_target(el)}#{inner(el, opts)}}"
end
def convert_strong(el, opts)
"\\textbf{#{latex_link_target(el)}#{inner(el, opts)}}"
end
# Inspired by Maruku: entity conversion table based on the one from htmltolatex
# (http://sourceforge.net/projects/htmltolatex/), with some small adjustments/additions
ENTITY_CONV_TABLE = {
913 => ['$A$'],
914 => ['$B$'],
915 => ['$\Gamma$'],
916 => ['$\Delta$'],
917 => ['$E$'],
918 => ['$Z$'],
919 => ['$H$'],
920 => ['$\Theta$'],
921 => ['$I$'],
922 => ['$K$'],
923 => ['$\Lambda$'],
924 => ['$M$'],
925 => ['$N$'],
926 => ['$\Xi$'],
927 => ['$O$'],
928 => ['$\Pi$'],
929 => ['$P$'],
931 => ['$\Sigma$'],
932 => ['$T$'],
933 => ['$Y$'],
934 => ['$\Phi$'],
935 => ['$X$'],
936 => ['$\Psi$'],
937 => ['$\Omega$'],
945 => ['$\alpha$'],
946 => ['$\beta$'],
947 => ['$\gamma$'],
948 => ['$\delta$'],
949 => ['$\epsilon$'],
950 => ['$\zeta$'],
951 => ['$\eta$'],
952 => ['$\theta$'],
953 => ['$\iota$'],
954 => ['$\kappa$'],
955 => ['$\lambda$'],
956 => ['$\mu$'],
957 => ['$\nu$'],
958 => ['$\xi$'],
959 => ['$o$'],
960 => ['$\pi$'],
961 => ['$\rho$'],
963 => ['$\sigma$'],
964 => ['$\tau$'],
965 => ['$\upsilon$'],
966 => ['$\phi$'],
967 => ['$\chi$'],
968 => ['$\psi$'],
969 => ['$\omega$'],
962 => ['$\varsigma$'],
977 => ['$\vartheta$'],
982 => ['$\varpi$'],
8230 => ['\ldots'],
8242 => ['$\prime$'],
8254 => ['-'],
8260 => ['/'],
8472 => ['$\wp$'],
8465 => ['$\Im$'],
8476 => ['$\Re$'],
8501 => ['$\aleph$'],
8226 => ['$\bullet$'],
8482 => ['$^{\rm TM}$'],
8592 => ['$\leftarrow$'],
8594 => ['$\rightarrow$'],
8593 => ['$\uparrow$'],
8595 => ['$\downarrow$'],
8596 => ['$\leftrightarrow$'],
8629 => ['$\hookleftarrow$'],
8657 => ['$\Uparrow$'],
8659 => ['$\Downarrow$'],
8656 => ['$\Leftarrow$'],
8658 => ['$\Rightarrow$'],
8660 => ['$\Leftrightarrow$'],
8704 => ['$\forall$'],
8706 => ['$\partial$'],
8707 => ['$\exists$'],
8709 => ['$\emptyset$'],
8711 => ['$\nabla$'],
8712 => ['$\in$'],
8715 => ['$\ni$'],
8713 => ['$\notin$'],
8721 => ['$\sum$'],
8719 => ['$\prod$'],
8722 => ['$-$'],
8727 => ['$\ast$'],
8730 => ['$\surd$'],
8733 => ['$\propto$'],
8734 => ['$\infty$'],
8736 => ['$\angle$'],
8743 => ['$\wedge$'],
8744 => ['$\vee$'],
8745 => ['$\cap$'],
8746 => ['$\cup$'],
8747 => ['$\int$'],
8756 => ['$\therefore$', 'amssymb'],
8764 => ['$\sim$'],
8776 => ['$\approx$'],
8773 => ['$\cong$'],
8800 => ['$\neq$'],
8801 => ['$\equiv$'],
8804 => ['$\leq$'],
8805 => ['$\geq$'],
8834 => ['$\subset$'],
8835 => ['$\supset$'],
8838 => ['$\subseteq$'],
8839 => ['$\supseteq$'],
8836 => ['$\nsubset$', 'amssymb'],
8853 => ['$\oplus$'],
8855 => ['$\otimes$'],
8869 => ['$\perp$'],
8901 => ['$\cdot$'],
8968 => ['$\rceil$'],
8969 => ['$\lceil$'],
8970 => ['$\lfloor$'],
8971 => ['$\rfloor$'],
9001 => ['$\rangle$'],
9002 => ['$\langle$'],
9674 => ['$\lozenge$', 'amssymb'],
9824 => ['$\spadesuit$'],
9827 => ['$\clubsuit$'],
9829 => ['$\heartsuit$'],
9830 => ['$\diamondsuit$'],
38 => ['\&'],
34 => ['"'],
39 => ['\''],
169 => ['\copyright'],
60 => ['\textless'],
62 => ['\textgreater'],
338 => ['\OE'],
339 => ['\oe'],
352 => ['\v{S}'],
353 => ['\v{s}'],
376 => ['\"Y'],
710 => ['\textasciicircum'],
732 => ['\textasciitilde'],
8211 => ['--'],
8212 => ['---'],
8216 => ['`'],
8217 => ['\''],
8220 => ['``'],
8221 => ['\'\''],
8224 => ['\dag'],
8225 => ['\ddag'],
8240 => ['\permil', 'wasysym'],
8364 => ['\euro', 'eurosym'],
8249 => ['\guilsinglleft'],
8250 => ['\guilsinglright'],
8218 => ['\quotesinglbase', 'mathcomp'],
8222 => ['\quotedblbase', 'mathcomp'],
402 => ['\textflorin', 'mathcomp'],
381 => ['\v{Z}'],
382 => ['\v{z}'],
160 => ['~'],
161 => ['\textexclamdown'],
163 => ['\pounds'],
164 => ['\currency', 'wasysym'],
165 => ['\textyen', 'textcomp'],
166 => ['\brokenvert', 'wasysym'],
167 => ['\S'],
171 => ['\guillemotleft'],
187 => ['\guillemotright'],
174 => ['\textregistered'],
170 => ['\textordfeminine'],
172 => ['$\neg$'],
173 => ['\-'],
176 => ['$\degree$', 'mathabx'],
177 => ['$\pm$'],
180 => ['\''],
181 => ['$\mu$'],
182 => ['\P'],
183 => ['$\cdot$'],
186 => ['\textordmasculine'],
162 => ['\cent', 'wasysym'],
185 => ['$^1$'],
178 => ['$^2$'],
179 => ['$^3$'],
189 => ['$\frac{1}{2}$'],
188 => ['$\frac{1}{4}$'],
190 => ['$\frac{3}{4}'],
192 => ['\`A'],
193 => ['\\\'A'],
194 => ['\^A'],
195 => ['\~A'],
196 => ['\"A'],
197 => ['\AA'],
198 => ['\AE'],
199 => ['\cC'],
200 => ['\`E'],
201 => ['\\\'E'],
202 => ['\^E'],
203 => ['\"E'],
204 => ['\`I'],
205 => ['\\\'I'],
206 => ['\^I'],
207 => ['\"I'],
208 => ['$\eth$', 'amssymb'],
209 => ['\~N'],
210 => ['\`O'],
211 => ['\\\'O'],
212 => ['\^O'],
213 => ['\~O'],
214 => ['\"O'],
215 => ['$\times$'],
216 => ['\O'],
217 => ['\`U'],
218 => ['\\\'U'],
219 => ['\^U'],
220 => ['\"U'],
221 => ['\\\'Y'],
222 => ['\Thorn', 'wasysym'],
223 => ['\ss'],
224 => ['\`a'],
225 => ['\\\'a'],
226 => ['\^a'],
227 => ['\~a'],
228 => ['\"a'],
229 => ['\aa'],
230 => ['\ae'],
231 => ['\cc'],
232 => ['\`e'],
233 => ['\\\'e'],
234 => ['\^e'],
235 => ['\"e'],
236 => ['\`i'],
237 => ['\\\'i'],
238 => ['\^i'],
239 => ['\"i'],
240 => ['$\eth$'],
241 => ['\~n'],
242 => ['\`o'],
243 => ['\\\'o'],
244 => ['\^o'],
245 => ['\~o'],
246 => ['\"o'],
247 => ['$\divide$'],
248 => ['\o'],
249 => ['\`u'],
250 => ['\\\'u'],
251 => ['\^u'],
252 => ['\"u'],
253 => ['\\\'y'],
254 => ['\thorn', 'wasysym'],
255 => ['\"y'],
8201 => ['\thinspace'],
8194 => ['\hskip .5em\relax'],
8195 => ['\quad'],
} # :nodoc:
ENTITY_CONV_TABLE.each_value {|v| v[0] = "{}#{v[0]}" }
def entity_to_latex(entity)
text, package = ENTITY_CONV_TABLE[entity.code_point]
if text
@data[:packages] << package if package
text
else
warning("Couldn't find entity with code #{entity.code_point} in substitution table!")
''
end
end
def convert_entity(el, _opts)
entity_to_latex(el.value)
end
TYPOGRAPHIC_SYMS = {
mdash: '---', ndash: '--', hellip: '\ldots{}',
laquo_space: '\guillemotleft{}~', raquo_space: '~\guillemotright{}',
laquo: '\guillemotleft{}', raquo: '\guillemotright{}'
} # :nodoc:
def convert_typographic_sym(el, _opts)
if (result = @options[:typographic_symbols][el.value])
escape(result)
else
TYPOGRAPHIC_SYMS[el.value]
end
end
def convert_smart_quote(el, opts)
res = entity_to_latex(smart_quote_entity(el)).chomp('{}')
res << "{}" if ((nel = opts[:parent].children[opts[:index] + 1]) && nel.type == :smart_quote) || res =~ /\w$/
res
end
def convert_math(el, _opts)
@data[:packages] += %w[amssymb amsmath amsthm amsfonts]
if el.options[:category] == :block
if el.value =~ /\A\s*\\begin\{/
el.value
else
latex_environment('displaymath', el, el.value)
end
else
"$#{el.value}$"
end
end
def convert_abbreviation(el, _opts)
@data[:packages] += %w[acronym]
"\\ac{#{normalize_abbreviation_key(el.value)}}"
end
# Normalize the abbreviation key so that it only contains allowed ASCII character
def normalize_abbreviation_key(key)
key.gsub(/\W/) {|m| m.unpack('H*').first }
end
# Wrap the +text+ inside a LaTeX environment of type +type+. The element +el+ is passed on to
# the method #attribute_list -- the resulting string is appended to both the \\begin and the
# \\end lines of the LaTeX environment for easier post-processing of LaTeX environments.
def latex_environment(type, el, text)
attrs = attribute_list(el)
"\\begin{#{type}}#{latex_link_target(el)}#{attrs}\n#{text.rstrip}\n\\end{#{type}}#{attrs}\n"
end
# Return a string containing a valid \hypertarget command if the element has an ID defined, or
# +nil+ otherwise. If the parameter +add_label+ is +true+, a \label command will also be used
# additionally to the \hypertarget command.
def latex_link_target(el, add_label = false)
if (id = el.attr['id'])
"\\hypertarget{#{id}}{}#{add_label ? "\\label{#{id}}" : ''}"
else
nil
end
end
# Return a LaTeX comment containing all attributes as 'key="value"' pairs.
def attribute_list(el)
attrs = el.attr.map {|k, v| v.nil? ? '' : " #{k}=\"#{v}\"" }.compact.sort.join('')
attrs = " % #{attrs}" unless attrs.empty?
attrs
end
ESCAPE_MAP = {
"^" => "\\^{}",
"\\" => "\\textbackslash{}",
"~" => "\\ensuremath{\\sim}",
"|" => "\\textbar{}",
"<" => "\\textless{}",
">" => "\\textgreater{}",
"[" => "{[}",
"]" => "{]}",
}.merge(Hash[*("{}$%&_#".each_char.map {|c| [c, "\\#{c}"] }.flatten)]) # :nodoc:
ESCAPE_RE = Regexp.union(*ESCAPE_MAP.collect {|k, _v| k }) # :nodoc:
# Escape the special LaTeX characters in the string +str+.
def escape(str)
str.gsub(ESCAPE_RE) {|m| ESCAPE_MAP[m] }
end
end
end
end