<?php

namespace MediaWiki\Extension\AbuseFilter\Parser;

/**
 * Abuse filter parser.
 * Copyright © Victor Vasiliev, 2008.
 * Based on ideas by Andrew Garrett
 * Distributed under GNU GPL v2 terms.
 *
 * Types of token:
 * * T_NONE - special-purpose token
 * * T_BRACE  - ( or )
 * * T_COMMA - ,
 * * T_OP - operator like + or ^
 * * T_NUMBER - number
 * * T_STRING - string, in "" or ''
 * * T_KEYWORD - keyword
 * * T_ID - identifier
 * * T_STATEMENT_SEPARATOR - ;
 * * T_SQUARE_BRACKETS - [ or ]
 *
 * Levels of parsing:
 * * Entry - catches unexpected characters
 * * Semicolon - ;
 * * Set - :=
 * * Conditionals (IF) - if-then-else-end, cond ? a :b
 * * BoolOps (BO) - &, |, ^
 * * CompOps (CO) - ==, !=, ===, !==, >, <, >=, <=
 * * SumRel (SR) - +, -
 * * MulRel (MR) - *, /, %
 * * Pow (P) - **
 * * BoolNeg (BN) - ! operation
 * * SpecialOperators (SO) - in and like
 * * Unarys (U) - plus and minus in cases like -5 or -(2 * +2)
 * * ArrayElement (AE) - array[number]
 * * Braces (B) - ( and )
 * * Functions (F)
 * * Atom (A) - return value
 */
class AFPToken {
	public const TNONE = 'T_NONE';
	public const TID = 'T_ID';
	public const TKEYWORD = 'T_KEYWORD';
	public const TSTRING = 'T_STRING';
	public const TINT = 'T_INT';
	public const TFLOAT = 'T_FLOAT';
	public const TOP = 'T_OP';
	public const TBRACE = 'T_BRACE';
	public const TSQUAREBRACKET = 'T_SQUARE_BRACKET';
	public const TCOMMA = 'T_COMMA';
	public const TSTATEMENTSEPARATOR = 'T_STATEMENT_SEPARATOR';

	public function __construct(
		public readonly string $type = self::TNONE,
		public readonly mixed $value = null,
		public readonly int $pos = 0
	) {
	}
}
