asciidoctor extension to replace patterns to enable german quotes

replace-chars.rb

require 'asciidoctor/extensions' unless RUBY_ENGINE == 'opal'
MAP_CHARS = {
    '@,,' => '„',
    '@,' => '‚',
    '@´´' => '“',
    '@´' => '‘',
};

class ReplaceSubsProcessor < Asciidoctor::Extensions::Postprocessor
    FindReplacementTokensRx = /@(,,?|´´?)/

    def process document, output
        output.gsub(FindReplacementTokensRx) { decimal_for_name $& }
    end

    def decimal_for_name name
        if (ref = MAP_CHARS[name])
            ref
        else
            name
        end
    end
end

Extensions.register :sr_replace_chars do
    if (@document.backend === 'html5') 
        postprocessor ReplaceSubsProcessor
    end
end

this extension can be accessed via the -r option in asciidoctor:

asciidoctor -r replace-chars sample.adoc