free_mutant/lib/mutant/ast.rb

54 lines
1.2 KiB
Ruby

module Mutant
# AST helpers
module AST
# Find last node satisfying predicate (as block)
#
# @return [Parser::AST::Node]
# if satisfying node is found
#
# @yield [Parser::AST::Node]
#
# @yieldreturn [Boolean]
# true in case node satisfies predicate
#
# @return [nil]
# otherwise
#
# @api private
#
def self.find_last_path(node, &predicate)
fail ArgumentError, 'block expected' unless block_given?
path = []
walk(node, [node]) do |candidate, stack|
if predicate.call(candidate)
path = stack.dup
end
end
path
end
# Walk all ast nodes keeping track of path
#
# @param [Parser::AST::Node] root
# @param [Array<Parser::AST::Node>] stack
#
# @yield [Parser::AST::Node]
# all nodes visited recursively including root
#
# @return [undefined]
#
# @api private
#
def self.walk(node, stack, &block)
block.call(node, stack)
node.children.grep(Parser::AST::Node) do |child|
stack.push(child)
walk(child, stack, &block)
stack.pop
end
end
private_class_method :walk
end # AST
end # Mutant