(* This Source Code Form is subject to the terms of the Mozilla Public License,
  v. 2.0. If a copy of the MPL was not distributed with this file, You can
  obtain one at https://mozilla.org/MPL/2.0/. *)

import cstdio, common

const
  CHUNK_SIZE := 85536u

type
	ElnaLexerState = (
		start,
		colon,
		identifier,
		decimal,
		leading_zero,
		greater,
		minus,
		left_paren,
		less,
		dot,
		comment,
		closing_comment,
		character,
		character_escape,
		string,
		string_escape,
		number_sign,
		trait,
		finish
	)
  ElnaLexerToken* = record
    kind: ElnaLexerKind;
		start: String; (* DEPRECATED *)
		position: ElnaPosition
  end
  ElnaLexerBooleanToken* = record(ElnaLexerToken)
    value: Bool
  end
  ElnaLexerCharacterToken* = record(ElnaLexerToken)
    value: Char
  end
  ElnaLexerStringToken* = record(ElnaLexerToken)
    value: String
  end
  ElnaLexerIntegerToken* = record(ElnaLexerToken)
    value: Int
  end

  TransitionAction = proc(lexer: ^Lexer; token: ^ElnaLexerToken)
  (* DEPRECATED should be replaced with TransitionAction (but keeping the type name). *)
	ElnaLexerAction = (none, accumulate, skip, single, eof, finalize, composite, key_id, integer, delimited)

  ElnaLexerTransition = record
    action: ElnaLexerAction;
    next_state: ElnaLexerState
  end

	ElnaLexerCursor = record
		state: ElnaLexerState;
		start: ^Char;
		finish: ^Char;
		token: ^ElnaLexerToken;
		position: ElnaPosition
	end

  BufferPosition* = record
    iterator: ^Char;
    location: ElnaLocation
  end
  Lexer* = record
    input: ^FILE;
    buffer: ^Char;
    size: Word;
    length: Word;
    start: BufferPosition;
    current: BufferPosition
  end
	ElnaLexerKind* = (
		identifier,
		_const,
		_var,
		_proc,
		_type,
		_begin,
		_end,
		_if,
		_then,
		_else,
		_elsif,
		_extern,
		_record,
		boolean,
		null,
		and,
		_or,
		_xor,
		not,
		_return,
		_cast,
		trait,
		left_paren,
		right_paren,
		left_square,
		right_square,
		greater_equal,
		less_equal,
		greater_than,
		less_than,
		not_equal,
		equals,
		semicolon,
		dot,
		comma,
		plus,
		_import,
		minus,
		multiplication,
		division,
		remainder,
		assignment,
		colon,
		hat,
		at,
		comment,
		string,
		character,
		integer,
		word,
		_while,
    _defer,
    exclamation,
    shift_right,
    shift_left,
    pipe,
    _case,
    _do,
    _of,
		eof
	)
	(**
	 * Classification table assigns each possible character to a group (class). All
	 * characters of the same group a handled equivalently.
	 *)
	ElnaLexerClass = (
		invalid,
		digit,
		alpha,
		space,
		colon,
		equals,
		left_paren,
		right_paren,
		asterisk,
		backslash,
		single,
		hex,
		zero,
		x,
		eof,
		dot,
		minus,
		single_quote,
		double_quote,
		greater,
		less,
		other,
		number_sign
	)

end.