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|
# frozen_string_literal: true
module Dry
module Logic
class Rule
class Interface < ::Module
SPLAT = ["*rest"].freeze
attr_reader :arity
attr_reader :curried
def initialize(arity, curried)
@arity = arity
@curried = curried
if !variable_arity? && curried > arity
raise ArgumentError, "wrong number of arguments (#{curried} for #{arity})"
end
define_constructor if curried?
if constant?
define_constant_application
else
define_application
end
end
def constant?
arity.zero?
end
def variable_arity?
arity.negative?
end
def curried?
!curried.zero?
end
def unapplied
if variable_arity?
unapplied = arity.abs - 1 - curried
if unapplied.negative?
0
else
unapplied
end
else
arity - curried
end
end
def name
if constant?
"Constant"
else
arity_str =
if variable_arity?
"Variable#{arity.abs - 1}Arity"
else
"#{arity}Arity"
end
curried_str =
if curried?
"#{curried}Curried"
else
EMPTY_STRING
end
"#{arity_str}#{curried_str}"
end
end
def define_constructor
assignment =
if curried.equal?(1)
"@arg0 = @args[0]"
else
"#{curried_args.join(", ")} = @args"
end
module_eval(<<~RUBY, __FILE__, __LINE__ + 1)
def initialize(*)
super
#{assignment}
end
RUBY
end
def define_constant_application
module_exec do
def call(*)
if @predicate[]
Result::SUCCESS
else
Result.new(false, id) { ast }
end
end
def [](*)
@predicate[]
end
end
end
def define_application
splat = variable_arity? ? SPLAT : EMPTY_ARRAY
parameters = (unapplied_args + splat).join(", ")
application = "@predicate[#{(curried_args + unapplied_args + splat).join(", ")}]"
module_eval(<<~RUBY, __FILE__, __LINE__ + 1)
def call(#{parameters})
if #{application}
Result::SUCCESS
else
Result.new(false, id) { ast(#{parameters}) }
end
end
def [](#{parameters})
#{application}
end
RUBY
end
def curried_args
@curried_args ||= ::Array.new(curried) { |i| "@arg#{i}" }
end
def unapplied_args
@unapplied_args ||= ::Array.new(unapplied) { |i| "input#{i}" }
end
end
end
end
end
|
