Class: MxxRu::CmdLineOptionProcessor

Inherits:
Object
  • Object
show all
Includes:
Singleton
Defined in:
lib/mxx_ru/cmd_line_option_processor.rb

Overview

Singleton for centralized mechanizm of command line options parsing.

Since v.1.4.0

Each part of Mxx_ru which need some command line option must provider special option processor for CmdLineOptionProcessor singleton:

module MxxRu
module SomeLangSupport
  class OptionParser
    include Singleton
    ...
    def prepare( parser ) # Instance of OptionParser from stdlib.
      parser.separator ''
      parser.separator 'Some Language Support options:'

      parser.on( '-i', '--include PATH', 'Set up include path' ) do
        |path|
        ... some processig ...
      end
      ... setting another option handlers ...
    end
  end
end
end

# OptionParser must be added to CmdLineOptionProcessor.
MxxRu::CmdLineOptionProcessor.add_processor(
    MxxRu::SomeLangSupport::OptionParser.instance )

See examples of using this technique in MxxRu::Util::Mode and MxxRu::Cpp::Mode classes.

Instance Method Summary collapse

Constructor Details

#initialize ⇒ CmdLineOptionProcessor

Returns a new instance of CmdLineOptionProcessor.



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# File 'lib/mxx_ru/cmd_line_option_processor.rb', line 72

def initialize
  @processors = []
  @parsed = false
end

Instance Method Details

#add_processor(processor) ⇒ Object

Add yet another option processor for processors list.



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# File 'lib/mxx_ru/cmd_line_option_processor.rb', line 78

def add_processor( processor )
  @processors << processor
  @parsed = false
end

#parse ⇒ Object

Performs parsing of ARGV content by current processors.

Finishes work of script if –help or –version found in ARGV.



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# File 'lib/mxx_ru/cmd_line_option_processor.rb', line 86

def parse
  unless @parsed
    parser = OptionParser.new do |p|
      prepare_option_parser( p )
    end

    begin
      parser.parse( ARGV )
    rescue => x
      $stderr.puts "command line parsing error '#{x.message}'"
      exit( 2 )
    end

    @parsed = true
  end
end