Module: FunctionalLightService

Defined in:

lib/functional-light-service.rb,
lib/functional-light-service/action.rb,
lib/functional-light-service/errors.rb,
lib/functional-light-service/context.rb,
lib/functional-light-service/version.rb,
lib/functional-light-service/organizer.rb,
lib/functional-light-service/deprecations.rb,
lib/functional-light-service/configuration.rb,
lib/functional-light-service/functional/enum.rb,
lib/functional-light-service/functional/monad.rb,
lib/functional-light-service/functional/option.rb,
lib/functional-light-service/functional/result.rb,
lib/functional-light-service/functional/result.rb,
lib/functional-light-service/organizer/execute.rb,
lib/functional-light-service/organizer/iterate.rb,
lib/functional-light-service/organizer/reduce_if.rb,
lib/functional-light-service/context/key_verifier.rb,
lib/functional-light-service/localization_adapter.rb,
lib/functional-light-service/organizer/reduce_until.rb,
lib/functional-light-service/organizer/with_reducer.rb,
lib/functional-light-service/organizer/with_callback.rb,
lib/functional-light-service/testing/context_factory.rb,
lib/functional-light-service/organizer/scoped_reducable.rb,
lib/functional-light-service/organizer/with_reducer_factory.rb,
lib/functional-light-service/organizer/with_reducer_log_decorator.rb

Defined Under Namespace

Modules: Action, Deprecations, Enum, Monad, Organizer, Prelude, Testing Classes: Configuration, Context, EnumBuilder, ExpectedKeysNotInContextError, FailWithRollbackError, LocalizationAdapter, Option, PromisedKeysNotInContextError, ReservedKeysInContextError, Result

Constant Summary

VERSION =

"6.0.0"

Class Method Summary

• .enum(&block) ⇒ Object

  rubocop:disable Metrics/AbcSize rubocop:disable Metrics/CyclomaticComplexity rubocop:disable Metrics/MethodLength rubocop:disable Metrics/PerceivedComplexity.

• .impl(enum_type, &block) ⇒ Object

  rubocop:enable Metrics/AbcSize rubocop:enable Metrics/CyclomaticComplexity rubocop:enable Metrics/MethodLength rubocop:enable Metrics/PerceivedComplexity.

Class Method Details

.enum(&block) ⇒ Object

rubocop:disable Metrics/AbcSize rubocop:disable Metrics/CyclomaticComplexity rubocop:disable Metrics/MethodLength rubocop:disable Metrics/PerceivedComplexity

# File 'lib/functional-light-service/functional/enum.rb', line 158

def enum(&block)
  mod = Class.new do # the enum to be built
    private_class_method :new

    def self.match(obj, &block)
      # Binding#receiver: stesso risultato di binding.eval('self') senza eval
      caller_ctx = block.binding.receiver

      matcher = self::Matcher.new(obj)
      matcher.instance_eval(&block)

      # exhaustiveness check su classi memoizzate: niente split/sort di
      # stringhe per chiamata
      covered = matcher.matches.map { |e| e[1] }
      missing = variant_classes.reject { |klass| covered.include?(klass) }
      unless missing.empty?
        missing_names = missing.map { |klass| klass.name.split('::')[-1].to_sym }
        raise Enum::MatchError, "Match is non-exhaustive, #{missing_names} not covered"
      end

      type_matches = matcher.matches.select { |r| r[0].is_a?(r[1]) }

      type_matches.each do |match|
        obj, _type, block, args, guard = match

        return caller_ctx.instance_eval(&block) if args.empty?

        if args.count != obj.args.count
          msg = "Pattern (#{args.join(', ')}) must match (#{obj.args.join(', ')})"
          raise Enum::MatchError, msg
        end

        guard_ctx = guard_context(obj, args)
        return caller_ctx.instance_exec(* obj.wrapped_values, &block) unless guard

        if guard && guard_ctx.instance_exec(obj, &guard)
          return caller_ctx.instance_exec(* obj.wrapped_values, &block)
        end
      end

      raise Enum::MatchError, "No match could be made"
    end

    def self.variants
      constants - %i[Matcher MatchError]
    end

    def self.variant_classes
      @variant_classes ||= variants.map { |v| const_get(v) }.freeze
    end

    def self.guard_context(obj, args)
      # Struct.new definisce una classe: va fatto una volta per firma,
      # non a ogni match con guard
      @guard_structs ||= {}
      struct = @guard_structs[args] ||= Struct.new(*args)

      if obj.is_a?(FunctionalLightService::EnumBuilder::DataType::Binary)
        struct.new(*obj.value.values)
      else
        struct.new(obj.value)
      end
    end
  end
  enum = EnumBuilder.new(mod)
  enum.instance_eval(&block)

  type_variants = mod.constants

  matcher = Class.new do
    def initialize(obj)
      @obj = obj
      @matches = []
      @vars = []
    end

    attr_reader :matches, :vars

    def where(&guard)
      guard
    end

    type_variants.each do |m|
      define_method(m) do |guard = nil, &inner_block|
        raise ArgumentError, "No block given to `#{m}`" if inner_block.nil?

        params_spec = inner_block.parameters
        if params_spec.any? { |spec| spec.size < 2 }
          msg = "Unnamed param found in block parameters: #{params_spec.inspect}"
          raise ArgumentError, msg
        end
        if params_spec.any? { |spec| spec[0] != :req && spec[0] != :opt }
          msg = "Only :req & :opt params allowed; parameters=#{params_spec.inspect}"
          raise ArgumentError, msg
        end

        args = params_spec.map { |spec| spec[1] }

        type = mod.const_get(m)

        guard = nil if guard && !guard.is_a?(Proc)

        @matches << [@obj, type, inner_block, args, guard]
      end
    end
  end

  mod.const_set(:Matcher, matcher)

  type_variants.each do |variant|
    mod.singleton_class.class_exec do
      define_method(variant) do |*args|
        const_get(variant).new(*args)
      end
    end
  end
  mod
end

.impl(enum_type, &block) ⇒ Object

rubocop:enable Metrics/AbcSize rubocop:enable Metrics/CyclomaticComplexity rubocop:enable Metrics/MethodLength rubocop:enable Metrics/PerceivedComplexity

# File 'lib/functional-light-service/functional/enum.rb', line 281

def impl(enum_type, &block)
  enum_type.variants.each do |v|
    enum_type.const_get(v).class_eval(&block)
  end
end