free_mutant/lib/mutant/cli/classifier.rb
2013-08-05 00:23:42 -07:00

134 lines
2.8 KiB
Ruby

# encoding: utf-8
module Mutant
class CLI
# A classifier for input strings
class Classifier < Matcher
include AbstractType, Adamantium::Flat, Concord.new(:cache, :match)
include Equalizer.new(:identifier)
SCOPE_NAME_PATTERN = /[A-Za-z][A-Za-z\d_]*/.freeze
SCOPE_OPERATOR = '::'.freeze
CBASE_PATTERN = /\A#{SCOPE_OPERATOR}/.freeze
METHOD_NAME_PATTERN = Regexp.union(
/[A-Za-z_][A-Za-z\d_]*[!?=]?/,
*OPERATOR_METHODS.map(&:to_s)
).freeze
SCOPE_PATTERN = /
(?:#{SCOPE_OPERATOR})?#{SCOPE_NAME_PATTERN}
(?:#{SCOPE_OPERATOR}#{SCOPE_NAME_PATTERN})*
/x.freeze
REGISTRY = []
# Register classifier
#
# @return [undefined]
#
# @api private
#
def self.register
REGISTRY << self
end
private_class_method :register
# Return constant
#
# @param [String] location
#
# @return [Class|Module]
#
# @api private
#
def self.constant_lookup(location)
location
.sub(CBASE_PATTERN, EMPTY_STRING)
.split(SCOPE_OPERATOR)
.reduce(Object) do |parent, name|
parent.const_get(name, nil)
end
end
# Return matchers for input
#
# @return [Classifier]
# if a classifier handles the input
#
# @return [nil]
# otherwise
#
# @api private
#
def self.build(*arguments)
classifiers = REGISTRY.map { |descendant| descendant.run(*arguments) }
classifiers.compact!
raise if classifiers.length > 1
classifiers.first
end
# Run classifier
#
# @param [Cache] cache
#
# @param [String] input
#
# @return [Classifier]
# if input is handled by classifier
#
# @return [nil]
# otherwise
#
# @api private
#
def self.run(cache, input)
match = self::REGEXP.match(input)
return unless match
new(cache, match)
end
# No protected_class_method in ruby :(
class << self; protected :run; end
# Enumerate subjects
#
# @return [self]
# if block given
#
# @return [Enumerator<Subject>]
# otherwise
#
# @api private
#
def each(&block)
return to_enum unless block_given?
matcher.each(&block)
self
end
# Return identifier
#
# @return [String]
#
# @api private
#
def identifier
match.to_s
end
memoize :identifier
# Return matcher
#
# @return [Matcher]
#
# @api private
#
abstract_method :matcher
private :matcher
end # Classifier
end # CLI
end # Mutant