module RuboCop::NodePattern::Macros

return the captures, or `true` if there were none.
If the node matches, and no block is provided, the new method will
yield to the block (passing any captures as block arguments).
If the node matches, and a block is provided, the new method will
The new method will return nil if the node does not match

Define a method which applies a pattern to an AST node

def def_node_matcher(method_name, pattern_str)
  compiler = Compiler.new(pattern_str, 'node')
  src = "def #{method_name}(node = self" \
        "#{compiler.emit_trailing_params});" \
        "#{compiler.emit_method_code};end"
  location = caller_locations(1, 1).first
  class_eval(src, location.path, location.lineno)
end