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Contents
# frozen_string_literal: true
require 'ast'
require 'parser/ast/node'
module Opal
module AST
class Matcher
def initialize(&block)
@root = instance_exec(&block)
end
def s(type, *children)
Node.new(type, children)
end
def cap(capture)
Node.new(:capture, [capture])
end
def match(ast)
@captures = []
@root.match(ast, self) || (return false)
@captures
end
def inspect
"#<Opal::AST::Matcher: #{@root.inspect}>"
end
attr_accessor :captures
Node = Struct.new(:type, :children) do
def match(ast, matcher)
return false if ast.nil?
ast_parts = [ast.type] + ast.children
self_parts = [type] + children
return false if ast_parts.length != self_parts.length
ast_parts.length.times.all? do |i|
ast_elem = ast_parts[i]
self_elem = self_parts[i]
if self_elem.is_a?(Node) && self_elem.type == :capture
capture = true
self_elem = self_elem.children.first
end
res = case self_elem
when Node
self_elem.match(ast_elem, matcher)
when Array
self_elem.include?(ast_elem)
when :*
true
else
self_elem == ast_elem
end
matcher.captures << ast_elem if capture
res
end
end
def inspect
if type == :capture
"{#{children.first.inspect}}"
else
"s(#{type.inspect}, #{children.inspect[1..-2]})"
end
end
end
end
end
end
Version data entries
19 entries across 19 versions & 1 rubygems