Class: Puppet::Pal::FunctionSignature

Inherits:
Object
  • Object
show all
Defined in:
lib/puppet/pal/function_signature.rb

Overview

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

Instance Method Summary collapse

Constructor Details

#initialize(function_class) ⇒ FunctionSignature

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a new instance of FunctionSignature.

API:

  • private



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# File 'lib/puppet/pal/function_signature.rb', line 14

def initialize(function_class)
  @func = function_class
end

Instance Method Details

#callable_with?(args, callable = nil) {|String| ... } ⇒ Boolean

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.

Parameters:

  • The arguments as given to the function call

  • (defaults to: nil)

    An optional ruby Proc or puppet lambda given to the function

Yields:

  • (String) —

    a formatted error message describing a type mismatch if the function is not callable with given args + block

Returns:

  • true if the function can be called with given args + block, and false otherwise

API:

  • public



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# File 'lib/puppet/pal/function_signature.rb', line 29

def callable_with?(args, callable=nil)
  signatures = @func.dispatcher.to_type
  callables = signatures.is_a?(Puppet::Pops::Types::PVariantType) ? signatures.types : [signatures]

  return true if callables.any? {|t| t.callable_with?(args) }
  return false unless block_given?
  args_type = Puppet::Pops::Types::TypeCalculator.singleton.infer_set(callable.nil? ? args : args + [callable])
  error_message = Puppet::Pops::Types::TypeMismatchDescriber.describe_signatures(@func.name, @func.signatures, args_type)
  yield error_message
  false
end

#callables ⇒ Array<Puppet::Pops::Types::PCallableType] one callable per way the function can be called

Returns an array of Callable puppet data type

Returns:

  • Array<Puppet::Pops::Types::PCallableType] one callable per way the function can be called

API:

  • public



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# File 'lib/puppet/pal/function_signature.rb', line 46

def callables
  signatures = @func.dispatcher.to_type
  signatures.is_a?(Puppet::Pops::Types::PVariantType) ? signatures.types : [signatures]
end