A parser is a class that subclasses RDoc::Parser and implements

#initialize top_level, file_name, body, options, stats

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.

::for is a factory that creates the correct parser for a given filename extension. Parsers have to register themselves RDoc::Parser using ::parse_files_matching as when they are loaded:

require "rdoc/parser"

class RDoc::Parser::Xyz < RDoc::Parser
  parse_files_matching /\.xyz$/ # <<<<

  def initialize top_level, file_name, body, options, stats
    ...
  end

  def scan
    ...
  end
end

If a plain text file is detected, RDoc also looks for a shebang line in case the file is a shell script.

Namespace
Methods
A
B
C
F
N
P
Z
Attributes
[R] parsers

An Array of arrays that maps file extension (or name) regular expressions to parser classes that will parse matching filenames.

Use ::parse_files_matching to register a parser's file extensions.
Class Public methods
alias_extension(old_ext, new_ext)

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

Source: show | on GitHub 

# File ../ruby/lib/rdoc/parser.rb, line 60
def self.alias_extension(old_ext, new_ext)
  old_ext = old_ext.sub(/^\.(.*)/, '\1')
  new_ext = new_ext.sub(/^\.(.*)/, '\1')

  parser = can_parse "xxx.#{old_ext}"
  return false unless parser

  RDoc::Parser.parsers.unshift [/\.#{new_ext}$/, parser]

  true
end
binary?(file)

Determines if the file is a “binary” file which basically means it has content that an RDoc parser shouldn't try to consume.

Source: show | on GitHub 

# File ../ruby/lib/rdoc/parser.rb, line 76
def self.binary?(file)
  return false if file =~ /\.(rdoc|txt)$/

  s = File.read(file, 1024) or return false

  have_encoding = s.respond_to? :encoding

  if have_encoding then
    return false if s.encoding != Encoding::ASCII_8BIT and s.valid_encoding?
  end

  return true if s[0, 2] == Marshal.dump('')[0, 2] or s.index("\x00")

  if have_encoding then
    s.force_encoding Encoding.default_external

    not s.valid_encoding?
  else
    if 0.respond_to? :fdiv then
      s.count("\x00-\x7F", "^ -~\t\r\n").fdiv(s.size) > 0.3
    else # HACK 1.8.6
      (s.count("\x00-\x7F", "^ -~\t\r\n").to_f / s.size) > 0.3
    end
  end
end
can_parse(file_name)

Return a parser that can handle a particular extension

Source: show | on GitHub 

# File ../ruby/lib/rdoc/parser.rb, line 142
def self.can_parse(file_name)
  parser = RDoc::Parser.parsers.find { |regexp,| regexp =~ file_name }.last

  # HACK Selenium hides a jar file using a .txt extension
  return if parser == RDoc::Parser::Simple and zip? file_name

  # The default parser must not parse binary files
  ext_name = File.extname file_name
  return parser if ext_name.empty?
  return if parser == RDoc::Parser::Simple and ext_name !~ /txt|rdoc/

  parser
end
for(top_level, file_name, body, options, stats)

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

Source: show | on GitHub 

# File ../ruby/lib/rdoc/parser.rb, line 160
def self.for(top_level, file_name, body, options, stats)
  return if binary? file_name

  # If no extension, look for shebang
  if file_name !~ /\.\w+$/ && body =~ %r{\A#!(.+)} then
    shebang = $1
    case shebang
    when %r{env\s+ruby}, %r{/ruby}
      file_name = "dummy.rb"
    end
  end

  parser = can_parse file_name

  return unless parser

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

Creates a new Parser storing top_level, file_name, content, options and stats in instance variables.

Usually invoked by super

Source: show | on GitHub 

# File ../ruby/lib/rdoc/parser.rb, line 194
def initialize(top_level, file_name, content, options, stats)
  @top_level = top_level
  @file_name = file_name
  @content = content
  @options = options
  @stats = stats

  @preprocess = RDoc::Markup::PreProcess.new @file_name, @options.rdoc_include
  @preprocess.options = @options
end
parse_files_matching(regexp)

Record which file types this parser can understand.

It is ok to call this multiple times.

Source: show | on GitHub 

# File ../ruby/lib/rdoc/parser.rb, line 184
def self.parse_files_matching(regexp)
  RDoc::Parser.parsers.unshift [regexp, self]
end
process_directive(code_object, directive, value)

Processes common directives for CodeObjects for the C and Ruby parsers.

Applies directive's value to code_object, if appropriate

Source: show | on GitHub 

# File ../ruby/lib/rdoc/parser.rb, line 107
def self.process_directive code_object, directive, value
  warn "RDoc::Parser::process_directive is deprecated and wil be removed in RDoc 4.  Use RDoc::Markup::PreProcess#handle_directive instead" if $-w

  case directive
  when 'nodoc' then
    code_object.document_self = nil # notify nodoc
    code_object.document_children = value.downcase != 'all'
  when 'doc' then
    code_object.document_self = true
    code_object.force_documentation = true
  when 'yield', 'yields' then
    # remove parameter &block
    code_object.params.sub!(/,?\s*&\w+/, '') if code_object.params

    code_object.block_params = value
  when 'arg', 'args' then
    code_object.params = value
  end
end
zip?(file)

Checks if file is a zip file in disguise. Signatures from www.garykessler.net/library/file_sigs.html

Source: show | on GitHub 

# File ../ruby/lib/rdoc/parser.rb, line 131
def self.zip? file
  zip_signature = File.read file, 4

  zip_signature == "PK\x03\x04" or
    zip_signature == "PK\x05\x06" or
    zip_signature == "PK\x07\x08"
end