The Parle\Lexer class

The Parle\Lexer class

Introduction

(PECL parle >= 0.5.1)

Single state lexer class. Lexemes can be defined on the fly. If the particular lexer instance is meant to be used with Parle\Parser, the token IDs need to be taken from there. Otherwise, arbitrary token IDs can be supplied. This lexer can give a certain performance advantage over Parle\RLexer, if no multiple states are required. Note, that Parle\RParser is not compatible with this lexer.

Class synopsis

class Parle\Lexer {

/* Constants */

const int ICASE = 1;

const int DOT_NOT_LF = 2;

const int DOT_NOT_CRLF = 4;

const int SKIP_WS = 8;

const int MATCH_ZERO_LEN = 16;

/* Properties */

public bool $bol = false;

public int $flags = 0;

public int $state = 0;

public int $marker = 0;

public int $cursor = 0;

/* Methods */

public advance(): void

public build(): void

public callout(int $id, callable $callback): void

public consume(string $data): void

public dump(): void

public getToken(): Parle\Token

public insertMacro(string $name, string $regex): void

public push(string $regex, int $id): void

public reset(int $pos): void

}

Predefined Constants

Parle\Lexer::ICASE Parle\Lexer::DOT_NOT_LF Parle\Lexer::DOT_NOT_CRLF Parle\Lexer::SKIP_WS Parle\Lexer::MATCH_ZERO_LEN

Properties

bol

Start of input flag.

flags

Lexer flags.

state

Current lexer state, readonly.

marker

Position of the latest token match, readonly.

cursor

Current input offset, readonly.

Table of Contents

• Parle\Lexer::advance — Process next lexer rule
• Parle\Lexer::build — Finalize the lexer rule set
• Parle\Lexer::callout — Define token callback
• Parle\Lexer::consume — Pass the data for processing
• Parle\Lexer::dump — Dump the state machine
• Parle\Lexer::getToken — Retrieve the current token
• Parle\Lexer::insertMacro — Insert regex macro
• Parle\Lexer::push — Add a lexer rule
• Parle\Lexer::reset — Reset lexer

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https://www.php.net/manual/en/class.parle-lexer.php