free_mutant/lib/mutant/cli/classifier.rb
2013-10-20 21:56:30 -07:00

133 lines
2.9 KiB
Ruby

# encoding: utf-8
module Mutant
class CLI
# A classifier for input strings
class Classifier
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(regexp)
REGISTRY[regexp] = 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
#
# @param [Cache] cache
# @param [String] pattern
#
# @return [Matcher]
# if a classifier handles the input
#
# @raise [RuntimeError]
# otherwise
#
# @api private
#
def self.run(cache, pattern)
matches = find(pattern)
case matches.length
when 0
raise Error, "No matcher handles: #{pattern.inspect}"
when 1
klass, match = matches.first
klass.new(cache, match).matcher
else
raise Error, "More than one matcher found for: #{pattern.inspect}"
end
end
# Find classifiers
#
# @param [String] input
#
# @api private
#
def self.find(input)
REGISTRY.each_with_object([]) do |(regexp, klass), matches|
match = regexp.match(input)
if match
matches << [klass, match]
end
end
end
private_class_method :find
# 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