Class: Elisp::Parser

Inherits:
Object
  • Object
show all
Defined in:
lib/elisp/parser.rb

Constant Summary collapse

HEADER_LINE = 
%r{
  ;;;[ ]
  (?<title>[a-z]+[.]el)[ ]---[ ](?<desc>.*?)
  (?:[ ]+-[*]-[ ]*(?<vars>.*?)[ ]*-[*]-)?
  \n+
}x
COMMENT = 
/ *;; (?<comment>.*)\n/
CODE = 
%r{
  (?<content>
    (?:
      [A-Za-z0-9&,.:=?_#'`<>()\[\]\t +*/-]
      | [?]\\.
      | "(?:[^\\"]|\\(?:.|\n))*"
    )+?
    (?:[ ]*;.*)?
    | ;;;[#][#][#]autoload.*
  )
  \n
}x
BLANKLINES = 
/\n+/
CODE_OR_BLANKLINES = 
Regexp.union(CODE, BLANKLINES)
DEFAULT_CSS = 
"<style>#{css}</style>"
HEADING = 
%r{
  ;;;(?<level>;*)[ ](?<title>.+)\n
  (?:(?:;;)?\n)*
}x

Instance Method Summary collapse

Constructor Details

#initialize(input) ⇒ Parser

Returns a new instance of Parser.



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# File 'lib/elisp/parser.rb', line 50

def initialize(input)
  @scanner = StringScanner.new(input.read)
  @state = :start
  @nodes = []
end

Instance Method Details

#make_major_para ⇒ Object 



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# File 'lib/elisp/parser.rb', line 134

def make_major_para
  paras = [@nodes.pop.to_minor_para]
  while (node = @nodes.pop)
    if node.is_a?(Elisp::MinorPara)
      paras.unshift(node)
    else
      @nodes.push(node)
      break
    end
  end
  @nodes << Elisp::MajorPara.new(paras)
end

#pandoc_json_object ⇒ Object 



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# File 'lib/elisp/parser.rb', line 165

def pandoc_json_object
  {
    "pandoc-api-version": [1,23,1,1],
    "meta": {},
    "blocks": @nodes.map(&:pandoc_json_object),
  }
end

#parse ⇒ Object 



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# File 'lib/elisp/parser.rb', line 56

def parse
  until @scanner.eos?

    if @state == :start && @scanner.skip(HEADER_LINE)
      @nodes << Elisp::Heading.new(@scanner[:title], level: 1)
      @nodes << Elisp::Desc.new(@scanner[:desc])
      @nodes << Elisp::Variables.new(@scanner[:vars])
      @state = :after_header_line

    elsif [:after_header_line,
           :after_major_para,
           :after_minor_para,
           :after_code,
           :after_page_delimiter,
           :after_heading].include?(@state) &&
          @scanner.skip(HEADING)
      level = @scanner[:level].size
      title = @scanner[:title]
      if level.zero?
        if ["Commentary:", "Code:"].include?(title)
          title.chop!
        elsif title.match?(/[a-z]+[.]el ends here/)
          next  # validate file name?
        end
      end
      @nodes << Elisp::Heading.new(title, level: level + 2)
      @state = :after_heading

    elsif [:after_heading,
           :after_major_para,
           :after_minor_para,
           :after_code,
           :after_header_line].include?(@state) &&
          @scanner.skip(COMMENT)
      @nodes << Elisp::Comment.new(@scanner[:comment])
      @state = :after_comment

    elsif @state == :after_comment && @scanner.skip(";;\n")
      @nodes[-1] = @nodes.last.to_minor_para
      @state = :after_minor_para

    elsif @state == :after_comment && @scanner.skip(COMMENT)
      @nodes.last << @scanner[:comment]

    elsif @state == :after_comment && @scanner.skip(BLANKLINES)
      make_major_para
      @state = :after_major_para

    elsif [:after_major_para, :after_page_delimiter, :after_heading].include?(@state) &&
          @scanner.skip(CODE)
      @nodes << Elisp::Code.new(@scanner[:content])
      @state = :after_code

    elsif @state == :after_comment && @scanner.skip(CODE)
      make_major_para
      @nodes << Elisp::Code.new(@scanner[:content])
      @state = :after_code

    elsif @state == :after_code && @scanner.skip(CODE_OR_BLANKLINES)
      @nodes.last << @scanner[:content]

    elsif @state == :after_code && @scanner.skip(/\f\n+/)
      @nodes << Elisp::PageDelimiter.new
      @state = :after_page_delimiter

    else
      raise Elisp::Error, <<~MESSAGE
        parse failed
        --- rest line (#{@state}) ---
        #{@scanner.rest.lines.first.inspect}
        --- scanner ---
        #{@scanner.inspect}
      MESSAGE
    end
  end
  self
end

#write(output, css: nil) ⇒ Object 



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# File 'lib/elisp/parser.rb', line 147

def write(output, css: nil)
  css = css ? %(<link rel="stylesheet" href="#{CGI.escape(css)}">) : DEFAULT_CSS
  body = @nodes.map(&:html).join("\n")
  output.write(<<~END_HTML)
    <!doctype html>
    <html>
      <head>
        #{css}
        <meta charset="utf8">
        <meta name="viewport" content="width=device-width, initial-scale=1">
      </head>
      <body>
        <main>#{body}</main>
      </body>
    </html>
  END_HTML
end

#write_pandoc_json(output) ⇒ Object 



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# File 'lib/elisp/parser.rb', line 173

def write_pandoc_json(output)
  json = JSON.dump(pandoc_json_object)
  output.write(json)
end