lib/rdoc/parser.rb
# -*- coding: us-ascii -*-
# frozen_string_literal: true
##
# A parser is simple a class that subclasses RDoc::Parser and implements #scan
# to fill in an RDoc::TopLevel with parsed data.
#
# The initialize method takes an RDoc::TopLevel to fill with parsed content,
# the name of the file to be parsed, the content of the file, an RDoc::Options
# object and an RDoc::Stats object to inform the user of parsed items. The
# scan method is then called to parse the file and must return the
# RDoc::TopLevel object. By calling super these items will be set for you.
#
# In order to be used by RDoc the parser needs to register the file extensions
# it can parse. Use ::parse_files_matching to register extensions.
#
# require 'rdoc'
#
# class RDoc::Parser::Xyz < RDoc::Parser
# parse_files_matching /\.xyz$/
#
# def initialize top_level, file_name, content, options, stats
# super
#
# # extra initialization if needed
# end
#
# def scan
# # parse file and fill in @top_level
# end
# end
class RDoc::Parser
@parsers = []
class << self
##
# An Array of arrays that maps file extension (or name) regular
# expressions to parser classes that will parse matching filenames.
#
# Use parse_files_matching to register a parser's file extensions.
attr_reader :parsers
end
##
# The name of the file being parsed
attr_reader :file_name
##
# Alias an extension to another extension. After this call, files ending
# "new_ext" will be parsed using the same parser as "old_ext"
def self.alias_extension(old_ext, new_ext)
old_ext = old_ext.sub(/^\.(.*)/, '\1')
new_ext = new_ext.sub(/^\.(.*)/, '\1')
parser = can_parse_by_name "xxx.#{old_ext}"
return false unless parser
RDoc::Parser.parsers.unshift [/\.#{new_ext}$/, parser]
true
end
##
# Determines if the file is a "binary" file which basically means it has
# content that an RDoc parser shouldn't try to consume.
def self.binary?(file)
return false if file =~ /\.(rdoc|txt)$/
s = File.read(file, 1024) or return false
return true if s[0, 2] == Marshal.dump('')[0, 2] or s.index("\x00")
mode = 'r:utf-8' # default source encoding has been changed to utf-8
s.sub!(/\A#!.*\n/, '') # assume shebang line isn't longer than 1024.
encoding = s[/^\s*\#\s*(?:-\*-\s*)?(?:en)?coding:\s*([^\s;]+?)(?:-\*-|[\s;])/, 1]
mode = "rb:#{encoding}" if encoding
s = File.open(file, mode) {|f| f.gets(nil, 1024)}
not s.valid_encoding?
end
##
# Checks if +file+ is a zip file in disguise. Signatures from
# http://www.garykessler.net/library/file_sigs.html
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"
rescue
false
end
##
# Return a parser that can handle a particular extension
def self.can_parse file_name
parser = can_parse_by_name file_name
# HACK Selenium hides a jar file using a .txt extension
return if parser == RDoc::Parser::Simple and zip? file_name
parser
end
##
# Returns a parser that can handle the extension for +file_name+. This does
# not depend upon the file being readable.
def self.can_parse_by_name file_name
_, parser = RDoc::Parser.parsers.find { |regexp,| regexp =~ file_name }
# The default parser must not parse binary files
ext_name = File.extname file_name
return parser if ext_name.empty?
if parser == RDoc::Parser::Simple and ext_name !~ /txt|rdoc/ then
case mode = check_modeline(file_name)
when nil, 'rdoc' then # continue
else
RDoc::Parser.parsers.find { |_, p| return p if mode.casecmp?(p.name[/\w+\z/]) }
return nil
end
end
parser
rescue Errno::EACCES
end
##
# Returns the file type from the modeline in +file_name+
def self.check_modeline file_name
line = File.open file_name do |io|
io.gets
end
/-\*-\s*(.*?\S)\s*-\*-/ =~ line
return nil unless type = $1
if /;/ =~ type then
return nil unless /(?:\s|\A)mode:\s*([^\s;]+)/i =~ type
type = $1
end
return nil if /coding:/i =~ type
type.downcase
rescue ArgumentError
rescue Encoding::InvalidByteSequenceError # invalid byte sequence
end
##
# Finds and instantiates the correct parser for the given +file_name+ and
# +content+.
def self.for top_level, file_name, content, options, stats
return if binary? file_name
parser = use_markup content
unless parser then
parse_name = file_name
# If no extension, look for shebang
if file_name !~ /\.\w+$/ && content =~ %r{\A#!(.+)} then
shebang = $1
case shebang
when %r{env\s+ruby}, %r{/ruby}
parse_name = 'dummy.rb'
end
end
parser = can_parse parse_name
end
return unless parser
content = remove_modeline content
parser.new top_level, file_name, content, options, stats
rescue SystemCallError
nil
end
##
# Record which file types this parser can understand.
#
# It is ok to call this multiple times.
def self.parse_files_matching(regexp)
RDoc::Parser.parsers.unshift [regexp, self]
end
##
# Removes an emacs-style modeline from the first line of the document
def self.remove_modeline content
content.sub(/\A.*-\*-\s*(.*?\S)\s*-\*-.*\r?\n/, '')
end
##
# If there is a <tt>markup: parser_name</tt> comment at the front of the
# file, use it to determine the parser. For example:
#
# # markup: rdoc
# # Class comment can go here
#
# class C
# end
#
# The comment should appear as the first line of the +content+.
#
# If the content contains a shebang or editor modeline the comment may
# appear on the second or third line.
#
# Any comment style may be used to hide the markup comment.
def self.use_markup content
markup = content.lines.first(3).grep(/markup:\s+(\w+)/) { $1 }.first
return unless markup
# TODO Ruby should be returned only when the filename is correct
return RDoc::Parser::Ruby if %w[tomdoc markdown].include? markup
markup = Regexp.escape markup
_, selected = RDoc::Parser.parsers.find do |_, parser|
/^#{markup}$/i =~ parser.name.sub(/.*:/, '')
end
selected
end
##
# Creates a new Parser storing +top_level+, +file_name+, +content+,
# +options+ and +stats+ in instance variables. In +@preprocess+ an
# RDoc::Markup::PreProcess object is created which allows processing of
# directives.
def initialize top_level, file_name, content, options, stats
@top_level = top_level
@top_level.parser = self.class
@store = @top_level.store
@file_name = file_name
@content = content
@options = options
@stats = stats
@preprocess = RDoc::Markup::PreProcess.new @file_name, @options.rdoc_include
@preprocess.options = @options
end
autoload :RubyTools, "#{__dir__}/parser/ruby_tools"
autoload :Text, "#{__dir__}/parser/text"
##
# Normalizes tabs in +body+
def handle_tab_width(body)
if /\t/ =~ body
tab_width = @options.tab_width
body.split(/\n/).map do |line|
1 while line.gsub!(/\t+/) do
b, e = $~.offset(0)
' ' * (tab_width * (e-b) - b % tab_width)
end
line
end.join "\n"
else
body
end
end
end
# simple must come first in order to show up last in the parsers list
require_relative 'parser/simple'
require_relative 'parser/c'
require_relative 'parser/changelog'
require_relative 'parser/markdown'
require_relative 'parser/rd'
require_relative 'parser/ruby'