Class: ConfigParser::Switch

Inherits:
Option show all
Defined in:
lib/config_parser/switch.rb

Overview

Switch represents a special type of Option where both a positive (–switch) and negative (–no-switch) version of long should map to self. A short may be specified for Switch; it will always be treated like the positive switch.

Constant Summary

Constants inherited from Option

Option::LINE_FORMAT

Instance Attribute Summary collapse

Attributes inherited from Option

#arg_name, #block, #desc, #long, #short

Instance Method Summary collapse

Methods inherited from Option

#to_s

Constructor Details

#initialize(options = {}) ⇒ Switch

Initializes a new Switch. Raises an error if an arg_name is specified for self (as switches are intended to be boolean in nature), or if no long option is specified.

Raises:

  • (ArgumentError) 


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# File 'lib/config_parser/switch.rb', line 15

def initialize(options={})
  super
  raise ArgumentError, "arg_name specified for switch: #{arg_name}" if arg_name
  raise ArgumentError, "no long specified" unless long
  @negative_long = Utils.prefix_long(long, 'no-')
end

Instance Attribute Details

#negative_long ⇒ Object (readonly)

The negative long switch, determined from long.



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# File 'lib/config_parser/switch.rb', line 10

def negative_long
  @negative_long
end

Instance Method Details

#parse(switch, value, argv) ⇒ Object

Calls the block with false if the negative long is specified, or calls the block with true in all other cases. Raises an error if a value is specified.



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# File 'lib/config_parser/switch.rb', line 31

def parse(switch, value, argv)
  raise "value specified for switch: #{switch}" if value
  value = (switch == negative_long ? false : true)
  block ? block.call(value) : value
end

#switches ⇒ Object

Returns an array of non-nil switches mapping to self (ie [long, negative_long, short]).



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# File 'lib/config_parser/switch.rb', line 24

def switches
  [long, negative_long, short].compact
end