Class: Astel::Dispatcher

Inherits:
Object
  • Object
show all
Defined in:
lib/astel/dispatcher.rb

Defined Under Namespace

Classes: CallbackList, Traversal

Constant Summary collapse

NODE_CLASSES = 
Prism.constants.filter_map do |constant|
  value = Prism.const_get(constant)
  next unless value.is_a?(Class) && value < Prism::Node

  [NodeType.from_class_name(constant.to_s), value]
rescue NameError
  nil
end.to_h.freeze
NODE_TYPES = 
NODE_CLASSES.keys.to_set.freeze

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Dispatcher

Returns a new instance of Dispatcher.



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# File 'lib/astel/dispatcher.rb', line 75

def initialize
  @callbacks = {}
end

Instance Method Details

#on(node_type, callable = nil, &block) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/astel/dispatcher.rb', line 79

def on(node_type, callable = nil, &block)
  callback = callable || block
  raise ArgumentError, 'callback is required' unless callback

  type = node_type.to_sym
  raise ArgumentError, "unknown Prism node type: #{node_type}" unless NODE_TYPES.include?(type)
  raise ArgumentError, 'callback must respond to call' unless callback.respond_to?(:call)

  registered = @callbacks[type]
  if registered.is_a?(CallbackList)
    registered << callback
  elsif registered
    @callbacks[type] = CallbackList.new([registered, callback])
  else
    @callbacks[type] = callback
  end
  self
end

#run(ast) ⇒ Object 



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# File 'lib/astel/dispatcher.rb', line 98

def run(ast)
  return self unless ast

  Traversal.new(@callbacks).run(ast)
  self
end