# module RDoc::Encoding

This class is a wrapper around `File` `IO` and `Encoding` that helps `RDoc` load files and convert them to the correct encoding.

### Public Class Methods

change_encoding(text, encoding) click to toggle source

Changes encoding based on `encoding` without converting and returns new string

    # File lib/rdoc/encoding.rb, line 123
    def self.change_encoding text, encoding
      if text.kind_of? RDoc::Comment
        text.encode! encoding
      else
        # TODO: Remove this condition after Ruby 2.2 EOL
        if RUBY_VERSION < '2.3.0'
          text.force_encoding encoding
        else
          String.new text, encoding: encoding
        end
      end
    end

detect_encoding(string) click to toggle source

Detects the encoding of `string` based on the magic comment

    # File lib/rdoc/encoding.rb, line 103
    def self.detect_encoding string
      result = HEADER_REGEXP.match string
      name = result && result[:name]

      name ? Encoding.find(name) : nil
    end

read_file(filename, encoding, force_transcode = false) click to toggle source

Reads the contents of `filename` and handles any encoding directives in the file.

The content will be converted to the `encoding`. If the file cannot be converted a warning will be printed and nil will be returned.

If `force_transcode` is true the document will be transcoded and any unknown character in the target encoding will be replaced with '?'

    # File lib/rdoc/encoding.rb, line 32
    def self.read_file filename, encoding, force_transcode = false
      content = File.open filename, "rb" do |f| f.read end
      content.gsub!("\r\n", "\n") if RUBY_PLATFORM =~ /mswin|mingw/

      utf8 = content.sub!(/\A\xef\xbb\xbf/, '')

      enc = RDoc::Encoding.detect_encoding content
      content = RDoc::Encoding.change_encoding content, enc if enc

      begin
        encoding ||= Encoding.default_external
        orig_encoding = content.encoding

        if not orig_encoding.ascii_compatible? then
          content = content.encode encoding
        elsif utf8 then
          content = RDoc::Encoding.change_encoding content, Encoding::UTF_8
          content = content.encode encoding
        else
          # assume the content is in our output encoding
          content = RDoc::Encoding.change_encoding content, encoding
        end

        unless content.valid_encoding? then
          # revert and try to transcode
          content = RDoc::Encoding.change_encoding content, orig_encoding
          content = content.encode encoding
        end

        unless content.valid_encoding? then
          warn "unable to convert #{filename} to #{encoding}, skipping"
          content = nil
        end
      rescue Encoding::InvalidByteSequenceError,
             Encoding::UndefinedConversionError => e
        if force_transcode then
          content = RDoc::Encoding.change_encoding content, orig_encoding
          content = content.encode(encoding,
                                   :invalid => :replace,
                                   :undef => :replace,
                                   :replace => '?')
          return content
        else
          warn "unable to convert #{e.message} for #{filename}, skipping"
          return nil
        end
      end

      content
    rescue ArgumentError => e
      raise unless e.message =~ /unknown encoding name - (.*)/
      warn "unknown encoding name \"#{$1}\" for #{filename}, skipping"
      nil
    rescue Errno::EISDIR, Errno::ENOENT
      nil
    end

remove_frozen_string_literal(string) click to toggle source

    # File lib/rdoc/encoding.rb, line 89
    def self.remove_frozen_string_literal string
      string =~ /\A(?:#!.*\n)?(.*\n)/
      first_line = $1

      if first_line =~ /\A# +frozen[-_]string[-_]literal[=:].+$/i
        string = string.sub first_line, ''
      end

      string
    end

remove_magic_comment(string) click to toggle source

Removes magic comments and shebang

    # File lib/rdoc/encoding.rb, line 113
    def self.remove_magic_comment string
      string.sub HEADER_REGEXP do |s|
        s.gsub(/[^\n]/, '')
      end
    end