builder.rb

# frozen_string_literal: true

module RuboCop
  module AST
    # `RuboCop::AST::Builder` is an AST builder that is utilized to let `Parser`
    # generate ASTs with {RuboCop::AST::Node}.
    #
    # @example
    #   buffer = Parser::Source::Buffer.new('(string)')
    #   buffer.source = 'puts :foo'
    #
    #   builder = RuboCop::AST::Builder.new
    #   require 'parser/ruby25'
    #   parser = Parser::Ruby25.new(builder)
    #   root_node = parser.parse(buffer)
    class Builder < Parser::Builders::Default
      self.emit_forward_arg = true if respond_to?(:emit_forward_arg=)
      self.emit_match_pattern = true if respond_to?(:emit_match_pattern=)

      # @api private
      NODE_MAP = {
        and:          AndNode,
        and_asgn:     AndAsgnNode,
        alias:        AliasNode,
        arg:          ArgNode,
        blockarg:     ArgNode,
        forward_arg:  ArgNode,
        kwarg:        ArgNode,
        kwoptarg:     ArgNode,
        kwrestarg:    ArgNode,
        optarg:       ArgNode,
        restarg:      ArgNode,
        shadowarg:    ArgNode,
        args:         ArgsNode,
        array:        ArrayNode,
        lvasgn:       AsgnNode,
        ivasgn:       AsgnNode,
        cvasgn:       AsgnNode,
        gvasgn:       AsgnNode,
        block:        BlockNode,
        numblock:     BlockNode,
        break:        BreakNode,
        case_match:   CaseMatchNode,
        casgn:        CasgnNode,
        case:         CaseNode,
        class:        ClassNode,
        const:        ConstNode,
        def:          DefNode,
        defined?:     DefinedNode,
        defs:         DefNode,
        dstr:         DstrNode,
        ensure:       EnsureNode,
        for:          ForNode,
        forward_args: ForwardArgsNode,
        float:        FloatNode,
        hash:         HashNode,
        if:           IfNode,
        in_pattern:   InPatternNode,
        int:          IntNode,
        index:        IndexNode,
        indexasgn:    IndexasgnNode,
        irange:       RangeNode,
        erange:       RangeNode,
        kwargs:       HashNode,
        kwsplat:      KeywordSplatNode,
        lambda:       LambdaNode,
        module:       ModuleNode,
        next:         NextNode,
        op_asgn:      OpAsgnNode,
        or_asgn:      OrAsgnNode,
        or:           OrNode,
        pair:         PairNode,
        procarg0:     Procarg0Node,
        regexp:       RegexpNode,
        rescue:       RescueNode,
        resbody:      ResbodyNode,
        return:       ReturnNode,
        csend:        SendNode,
        send:         SendNode,
        str:          StrNode,
        xstr:         StrNode,
        sclass:       SelfClassNode,
        super:        SuperNode,
        zsuper:       SuperNode,
        sym:          SymbolNode,
        until:        UntilNode,
        until_post:   UntilNode,
        when:         WhenNode,
        while:        WhileNode,
        while_post:   WhileNode,
        yield:        YieldNode
      }.freeze

      # Generates {Node} from the given information.
      #
      # @return [Node] the generated node
      def n(type, children, source_map)
        node_klass(type).new(type, children, location: source_map)
      end

      # TODO: Figure out what to do about literal encoding handling...
      # More details here https://github.com/whitequark/parser/issues/283
      def string_value(token)
        value(token)
      end

      private

      def node_klass(type)
        NODE_MAP[type] || Node
      end
    end
  end
end