compiler.md

Compiler

This package is only for development and is installed by the command composer require phplrt/compiler --dev

The library is needed to create parsers from grammar files and is not used during the parsing itself, this is only required for development.

Before you begin to work with custom implementations of parsers, it is recommended that you review the EBNF

Loading

You can immediately load the grammar into memory and execute it using method $compiler->parse(...):

<?php
use Phplrt\Source\File;
use Phplrt\Compiler\Compiler;

$compiler = new Compiler();
$compiler->load(File::fromPatname(__DIR__ . '/path/to/file.pp2'));

echo $compiler->parse(File::fromSources('example text'));

Compilation

Reading a grammar is quite simple operation, but it still takes time to execute. After the grammar rules have been formulated, you can "fix" the version in a separate parser class that will contain all the logic and no longer require reading the source code. After you compile it into a class, this package (phplrt/compiler) can be excluded from composer dependencies.

use Phplrt\Source\File;
use Phplrt\Compiler\Compiler;

echo (new Compiler())
    ->load(File::fromPathname('path/to/grammar.pp2'))
    ->build();

This code example will create a parser class in the current directory with the required class and namespace names. An example of the result of generation can be found in an existing project here.