93 lines
2.4 KiB
Ruby
93 lines
2.4 KiB
Ruby
# -*- coding: utf-8 -*- #
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# frozen_string_literal: true
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module Rouge
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module Formatters
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class Tex < Formatter
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tag 'tex'
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# A map of TeX escape characters.
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# Newlines are handled specially by using #token_lines
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# spaces are preserved as long as they aren't at the beginning
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# of a line. see #tag_first for our initial-space strategy
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ESCAPE = {
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'&' => '\&',
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'%' => '\%',
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'$' => '\$',
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'#' => '\#',
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'_' => '\_',
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'{' => '\{',
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'}' => '\}',
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'~' => '{\textasciitilde}',
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'^' => '{\textasciicircum}',
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'|' => '{\textbar}',
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'\\' => '{\textbackslash}',
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'`' => '{\textasciigrave}',
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"'" => "'{}",
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'"' => '"{}',
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"\t" => '{\tab}',
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}
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ESCAPE_REGEX = /[#{ESCAPE.keys.map(&Regexp.method(:escape)).join}]/om
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def initialize(opts={})
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@prefix = opts.fetch(:prefix) { 'RG' }
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end
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def escape_tex(str)
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str.gsub(ESCAPE_REGEX, ESCAPE)
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end
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def stream(tokens, &b)
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# surround the output with \begin{RG*}...\end{RG*}
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yield "\\begin{#{@prefix}*}%\n"
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# we strip the newline off the last line to avoid
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# an extra line being rendered. we do this by yielding
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# the \newline tag *before* every line group except
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# the first.
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first = true
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token_lines tokens do |line|
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if first
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first = false
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else
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yield "\\newline%\n"
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end
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render_line(line, &b)
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end
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yield "%\n\\end{#{@prefix}*}%\n"
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end
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def render_line(line, &b)
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line.each do |(tok, val)|
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hphantom_tag(tok, val, &b)
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end
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end
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# Special handling for leading spaces, since they may be gobbled
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# by a previous command. We replace all initial spaces with
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# \hphantom{xxxx}, which renders an empty space equal to the size
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# of the x's.
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def hphantom_tag(tok, val)
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leading = nil
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val.sub!(/^[ ]+/) { leading = $&.size; '' }
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yield "\\hphantom{#{'x' * leading}}" if leading
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yield tag(tok, val) unless val.empty?
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end
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def tag(tok, val)
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if escape?(tok)
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val
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elsif tok == Token::Tokens::Text
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escape_tex(val)
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else
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"\\#@prefix{#{tok.shortname}}{#{escape_tex(val)}}"
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end
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end
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end
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end
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end
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