# encoding: utf-8
# frozen_string_literal: true

require "carbon/compiler/parser/firsts"
require "carbon/compiler/parser/helpers"
require "carbon/compiler/parser/common"
require "carbon/compiler/parser/root"
require "carbon/compiler/parser/statements"
require "carbon/compiler/parser/expressions"

module Carbon
  module Compiler
    # The parser.  This takes a series of tokens, generated by the {Scanner},
    # and derives structure from these tokens.  This makes the fundamental
    # bases of creating a concrete representation of what is in the file.
    class Parser
      include Parser::Helpers
      include Parser::Common
      include Parser::Root
      include Parser::Statements
      include Parser::Expressions

      # The scanner that acts as the source of the tokens.
      #
      # @return [Scanner]
      attr_reader :scanner

      # Initialize the parser.  It takes a scanner, and the project that
      # the parser is a part of.
      #
      # @param scanner [Scanner]
      # @param project [Project]
      def initialize(scanner)
        @scanner = scanner
        @file = @scanner.file
        @enum = @scanner.each
      end

      # Pretty inspect.
      #
      # @return [String]
      def inspect
        "#<#{self.class} #{@scanner.file.name}>"
      end

      # Parses the input.  This is cached to prevent multiple runs.
      #
      # @return [Parser::Node]
      def parse
        @_root ||= parse_root
      end
      alias_method :root, :parse

      # Destroys the cache for {#parse}, allowing the parsing to occur again.
      #
      # @return [void]
      def clear!
        @enum.reset
        @_root = nil
      end
    end
  end
end