Class: MadderLib::Conditional::Helper::TestBlock

Inherits:
Object
  • Object
show all
Defined in:
lib/madderlib/conditional/helper.rb

Constant Summary collapse

FALSE = 
lambda { false }
ONE = 
lambda { 1 }

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args, &block) ⇒ TestBlock

Returns a new instance of TestBlock.



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# File 'lib/madderlib/conditional/helper.rb', line 11

def initialize(*args, &block)
	if block
		#	if we get a block, use it!
		raise Error, 'block AND args provided, requires one or the other' if (args && (! args.empty?))
		raise Error, 'block arity should be 0; 1 (count) or; 2 (count, Context)' if (block.arity > 2)

		#	it will remain unchanging
		@criteria = block
	else
		#	leave the originals alone
		args = args.clone

		begin
			#	how does it start?
			arg = args.shift

			if Range === arg
				#	we received a Range
				@criteria = arg
			elsif arg.respond_to?(:integer?) && arg.integer?
				upper = args.first
				if upper && upper.respond_to?(:integer?) && upper.integer?
					#	we can make a Range from that
					@criteria = Range.new(arg, args.shift)
				else
					#	just a count
					@criteria = arg
				end
			else
				raise Error, "invalid test block argument : #{arg.inspect}"
			end
		rescue Error => e
			raise e
		rescue Exception => e
			#	wrap
			raise e
			raise Error.new("invalid test block argument : #{arg.inspect}", e)
		end

		#	beyond that, is there a unit?
		#		we deal with all of that during build
		@units = args.shift
	end
end

Instance Attribute Details

#criteria ⇒ Object (readonly)

Returns the value of attribute criteria.



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# File 'lib/madderlib/conditional/helper.rb', line 9

def criteria
  @criteria
end

Instance Method Details

#block ⇒ Object 



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# File 'lib/madderlib/conditional/helper.rb', line 58

def block
	if Proc === @criteria
		#	the block will do its own testing
		@criteria
	elsif Range === @criteria
		#	we'll stop somewhere in that range
		#		note that it's inclusive
		#		if the caller says '2 .. 4', 4 should be a possibility
		limit = unitize(@criteria.rand_inclusive)
		lambda {|count| count < limit }
	elsif @criteria.integer?
		limit = unitize(@criteria)
		lambda {|count| count < limit }
	else
		#	never will succeed
		FALSE
	end
end

#invoke(*args, &given_block) ⇒ Object 



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# File 'lib/madderlib/conditional/helper.rb', line 77

def invoke(*args, &given_block)
	#	take in a block, or use the internally held one
	#		allows for external buffering
	b = block_given? ? given_block : self.block
	p = args

	if b.arity < 1
		#	how interesting!  arity of -1
		b.call
	else
		#	only as many args as supported
		#		do not worry about shortfall; that'll be a failure
		p.pop while b.arity < p.size
		b.call *p
	end
end

#to_i(context) ⇒ Object 



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# File 'lib/madderlib/conditional/helper.rb', line 96

def to_i(context)
	value = nil

	if Proc === @criteria
		value = MadderLib::Context.invoke(@criteria, context)
	elsif Range === @criteria
		value = @criteria.max
	elsif @criteria.integer?
		value = @criteria
	end

	#	has to be an integer, by definition
	if value && value.respond_to?(:integer?) && value.integer?
		unitize(value)
	else
		nil
	end
end