Module RDoc::ParserFactory
In: rdoc/parsers/parserfactory.rb

A parser is simple a class that implements

  #initialize(file_name, body, options)

and

  #scan

The initialize method takes a file name to be used, the body of the file, and an RDoc::Options object. The scan method is then called to return an appropriately parsed TopLevel code object.

The ParseFactory is used to redirect to the correct parser given a filename extension. This magic works because individual parsers have to register themselves with us as they are loaded in. The do this using the following incantation

   require "rdoc/parsers/parsefactory"

   module RDoc

     class XyzParser
       extend ParseFactory                  <<<<
       parse_files_matching /\.xyz$/        <<<<

       def initialize(file_name, body, options)
         ...
       end

       def scan
         ...
       end
     end
   end

Just to make life interesting, if we suspect a plain text file, we also look for a shebang line just in case it’s a potential shell script

Methods

Constants

Parsers = Struct.new(:regexp, :parser)

Public Class methods

Alias an extension to another extension. After this call, files ending "new_ext" will be parsed using the same parser as "old_ext"

[Source]

# File rdoc/parsers/parserfactory.rb, line 70
    def ParserFactory.alias_extension(old_ext, new_ext)
      parser = ParserFactory.can_parse("xxx.#{old_ext}")
      return false unless parser
      @@parsers.unshift Parsers.new(Regexp.new("\\.#{new_ext}$"), parser.parser)
      true
    end

Return a parser that can handle a particular extension

[Source]

# File rdoc/parsers/parserfactory.rb, line 62
    def ParserFactory.can_parse(file_name)
      @@parsers.find {|p| p.regexp.match(file_name) }
    end

Find the correct parser for a particular file name. Return a SimpleParser for ones that we don’t know

[Source]

# File rdoc/parsers/parserfactory.rb, line 80
    def ParserFactory.parser_for(top_level, file_name, body, options, stats)
      # If no extension, look for shebang
      if file_name !~ /\.\w+$/ && body =~ %r{\A#!(.+)}
        shebang = $1
        case shebang
        when %r{env\s+ruby}, %r{/ruby}
          file_name = "dummy.rb"
        end
      end
      parser_description = can_parse(file_name)
      if parser_description
        parser = parser_description.parser 
      else
        parser = SimpleParser
      end

      parser.new(top_level, file_name, body, options, stats)
    end

Public Instance methods

Record the fact that a particular class parses files that match a given extension

[Source]

# File rdoc/parsers/parserfactory.rb, line 56
    def parse_files_matching(regexp)
      @@parsers.unshift Parsers.new(regexp, self)
    end

[Validate]