Given an array of placeholder values and a FastRoute uri definition build a url

route-to-url.php

<?php

function buildUrl($uri, array $params) {
    $matches = [];
    $pattern = '{\s* ([a-zA-Z_][a-zA-Z0-9_-]*) \s*(?:: \s* ([^{}]*(?:\{(?-1)\}[^{}]*)*))?\}';
    $optionalSegments = '\[.*'.$pattern.'\]';
    
    $uri = preg_replace_callback('~'.$optionalSegments.'~x', function($match) use ($params) {
        $uri = trim($match[0], '[]');
        if (isset($params[$match[1]])) {
            return trim($match[0],'[]');
        }
        return '';
    }, $uri);
    
    return preg_replace_callback('~'.$pattern.'~x', function($match) use ($params) {
        if (!isset($params[$match[1]])) {
            throw new RuntimeException("'".$match[1]."' not defined in input array");
        }
        return $params[$match[1]];
    }, $uri);
}

$uri = '/articles/{id:\d+}[/{name}]';

$params = [
    'id'=>15,
    'name'=>'Fred',
];

echo buildUrl($uri, $params);