Module: LangScan::Perl

Defined in:
lib/langscan/perl.rb

Constant Summary collapse

PERLTOKENIZER_PATH = 
$LOAD_PATH.map {|path|
  File.join(path, "langscan/perl/tokenizer.pl")
}.find {|path| File.file?(path) }

Class Method Summary collapse

Class Method Details

.abbrev ⇒ Object 



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# File 'lib/langscan/perl.rb', line 28

def abbrev
  "perl"
end

.extnames ⇒ Object 



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# File 'lib/langscan/perl.rb', line 32

def extnames
  [".pl", ".PL", ".pm", ".t" ] # XXX remove ".t"
end

.name ⇒ Object 



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# File 'lib/langscan/perl.rb', line 24

def name
  "Perl"
end

.open_tokenizer ⇒ Object 



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# File 'lib/langscan/perl.rb', line 45

def open_tokenizer 
  command_line = sprintf("perl %s 2>/dev/null", 
                         shell_escape(PERLTOKENIZER_PATH))
  @io = IO.popen(command_line, "r+")
end

.scan(input) ⇒ Object

LangScan::Perl.scan iterates over Perl program. It yields for each Fragment.



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# File 'lib/langscan/perl.rb', line 53

def scan(input)
  open_tokenizer if @io.nil? or @io.closed? # in case of Perl error
  @io.puts(input.length)
  @io.write(input)
  inputlen = input.length
  buflen   = 0
  begin
    while (buflen < inputlen)
      type    = @io.readline.chomp.intern
      lineno  = @io.readline.chomp.to_i
      byteno  = @io.readline.chomp.to_i
      bodylen = @io.readline.chomp.to_i
      text    = @io.read(bodylen)
      if type.nil? or text.nil? or lineno.nil? or byteno.nil?
        raise ScanFailed.new("Unexpected output from tokenizer.pl")
      end
      yield Fragment.new(type, text, lineno, byteno)
      @io.read(1) # newline
      buflen += bodylen
    end
  rescue EOFError
    @io.close
    raise  ScanFailed.new("tokenizer.pl failed to parse")
  end
end

.shell_escape(file_name) ⇒ Object 



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# File 'lib/langscan/perl.rb', line 41

def shell_escape(file_name)
  '"' + file_name.gsub(/([$"\\`])/, "\\\\\\1") + '"'
end