class Puppet::Pal::FunctionSignature
A FunctionSignature
is returned from `function_signature`. Its purpose is to answer questions about the function's parameters and if it can be called with a set of parameters.
It is also possible to get an array of puppet Callable data type where each callable describes one possible way the function can be called.
@api public
Public Class Methods
@api private
# File lib/puppet/pal/function_signature.rb 13 def initialize(function_class) 14 @func = function_class 15 end
Public Instance Methods
Returns true if the function can be called with the given arguments and false otherwise. If the function is not callable, and a code block is given, it is given a formatted error message that describes the type mismatch. That error message can be quite complex if the function has multiple dispatch depending on given types.
@param args [Array] The arguments as given to the function call @param callable [Proc, nil] An optional ruby Proc or puppet lambda given to the function @yield [String] a formatted error message describing a type mismatch if the function is not callable with given args + block @return [Boolean] true if the function can be called with given args + block, and false otherwise @api public
# File lib/puppet/pal/function_signature.rb 28 def callable_with?(args, callable=nil) 29 signatures = @func.dispatcher.to_type 30 callables = signatures.is_a?(Puppet::Pops::Types::PVariantType) ? signatures.types : [signatures] 31 32 return true if callables.any? {|t| t.callable_with?(args) } 33 return false unless block_given? 34 args_type = Puppet::Pops::Types::TypeCalculator.singleton.infer_set(callable.nil? ? args : args + [callable]) 35 error_message = Puppet::Pops::Types::TypeMismatchDescriber.describe_signatures(@func.name, @func.signatures, args_type) 36 yield error_message 37 false 38 end
Returns an array of Callable puppet data type @return [Array<Puppet::Pops::Types::PCallableType] one callable per way the function can be called
@api public
# File lib/puppet/pal/function_signature.rb 45 def callables 46 signatures = @func.dispatcher.to_type 47 signatures.is_a?(Puppet::Pops::Types::PVariantType) ? signatures.types : [signatures] 48 end