Creando un lexer en php

2ya_funciona_con_un_caracter.php

<?php
$tokens = [
    '(' =>  'open_parentesis',
    ')' =>  'close_parentesis',
    '=' =>  'igual',
    '[' =>  'open_corchete_cuadrado',
    ']' =>  'close_corchete_cuadrado',
];

$string = 'let hola = (uno) => [ uno ** 2, 5];';

$recurtion = function($stringFn, $iterator = 0, $previous_character = null, array $resulting_array = []) 
    use (&$recurtion, $tokens)
{
    $stringFn_iterator              = $stringFn[$iterator] ?? null;
    $temporary_previous_character   = $previous_character ?? null;
    $tokens_string_iterator         = $tokens[$stringFn_iterator] ?? null;
    
    $temporary_array = (isset($tokens_string_iterator))
        ? array_merge($resulting_array, [$tokens_string_iterator => $stringFn_iterator])
        : $resulting_array;
        
    return (isset($stringFn_iterator) && !isset($temporary_previous_character)) 
        ? $recurtion($stringFn, $iterator + 1, null, $temporary_array)
        : ((isset($previous_character))  
            ? $recurtion($stringFn, $iterator + 1, $temporary_previous_character, $temporary_array) 
            :$resulting_array);
};
var_dump($recurtion($string));

evaluador_simple_en_funcion.php

<?php
$fullString = "ignore everything except this (text hola mundo (esto es otro dentro de archivo) siguiente)";

$function = function($string)
{
    $beginning      = strpos($string, '('); #30
    $final          = strpos($string, ')'); # 35
    $string_length  = $final - $beginning; 
    return substr($string, $beginning + 1, $string_length - 1);
};

echo($function($fullString));

lexer_php.php

<?php

$uno = '(uno dos tres (cuatro cinco seis))(siete (catorce quince 16) ocho nueve diez)(once doce trece)';

$dos = function($tres, $cuatro = 0, $cinco = [])
{
    $seis = ($tres[$cuatro] == '(') ? $cinco + [$cuatro] : ;    
};

parser.php

<?php

$str = 'let hola = (uno) => [ uno ** 2, 5];';

$array = [
    'palabra_reservada' => 'let',
    'variable'          => 'hola',
    'igual'             => '=',
    'parentesis_open'   => '(',
    'variable'          => 'uno',
    'parentesis_close'  => ')',
    'flecha'            => '=>',
    'cuadrado_open'     => '[',
    'variable'          => 'uno',
    'simbolo'           => '**',
    'numero'            => '2',
    'coma'              => ',',
    'numero'            => '5',
    'cuadrado_close'    => ']',
    'punto_y_coma'      => ';',
];

segundo_ejercicio.php

<?php
$fullString = "ignore everything except this (text)";


$start = strpos($fullString, '('); #30
$spos = strpos($fullString, ')'); # 35
#$end = strlen($fullString) - strpos(')', $fullString); 
$len = strlen($fullString); # 36
#$end = $spos - $start; 
$end = $spos - $start; 
#$shortString = substr($fullString, $start, $end);
$shortString = substr($fullString, $start + 1, $end - 1);

echo($shortString);

tercero.php

<?php

$string_primero = '(uno dos tres (cuatro cinco seis))(siete (catorce quince 16) ocho nueve diez)(once doce trece)';

$funcion_recusiva = function($string, $indice = 0, $colector = []) use (&$funcion_recusiva)
{
    $seis = (isset($string[$indice]) && $string[$indice] == '(') ? array_merge($colector, [$indice]) : $colector ;
    return (isset($string[$indice + 1])) ? $funcion_recusiva($string, $indice + 1, $seis) : $seis;
};

var_dump($funcion_recusiva($string_primero));

ya_funciona_con_un_caracter.php

<?php
$tokens = [
    '(' =>  'open_parentesis',
    ')' =>  'close_parentesis',
    '=' =>  'igual',
    '[' =>  'open_corchete_cuadrado',
    ']' =>  'close_corchete_cuadrado',
];

$string = 'let hola = (uno) => [ uno ** 2, 5];';

$recurtion = function($stringFn, $iterator = 0, $previous_character = null, array $resulting_array = []) 
    use (&$recurtion, $tokens)
{
    $stringFn_iterator      = $stringFn[$iterator] ?? null;
    $tokens_string_iterator = $tokens[$stringFn_iterator] ?? null;
    
    $temporary_array = (isset($tokens_string_iterator))
        ? array_merge($resulting_array, [$tokens_string_iterator => $stringFn_iterator])
        : $resulting_array;
        
    return (!isset($stringFn_iterator)) 
        ? $resulting_array
        : $recurtion($stringFn, $iterator + 1, null, $temporary_array);
};
var_dump($recurtion($string));