simple routing library with type hints

routes-example.php

<?php
require __DIR__.'/routes.php';

use badphp\routes\{
  function get,
  function post,
  function lookup
};

# let's create some routes
$routes = [];

$routes[] = get('/index', function () {
  return "Hello everyone!\n";
});

$routes[] = get('/welcome/<name>', function ($params) {
  return "Welcome, {$params['name']}!\n";
});

$routes[] = post('/users', function () {
  return "User created!\n";
});

# match request against routes
list($func, $params) = lookup($routes, $argv[1], $argv[2]);

if ($func === null) {
  echo "Sorry, don't know what you mean!\n";
  exit;
}

# invoke matching action + args any way you like
echo $func($params);

routes.php

<?php
declare(strict_types=1);

namespace badphp\routes;

# get route mapper
function post(string $expr, callable $func): callable {
  return route('POST', $expr, $func);
}

# get route mapper
function get(string $expr, callable $func): callable {
  return route('GET', $expr, $func);
}

# get route mapper
function put(string $expr, callable $func): callable {
  return route('PUT', $expr, $func);
}

# get route mapper
function delete(string $expr, callable $func): callable {
  return route('DELETE', $expr, $func);
}

# creates a callable that ma
function route(string $verb, string $expr, callable $func): callable {

  # create lambda that does the route matching
  return function ($r_verb, $r_path) use ($verb, $expr, $func): array {

    $r_verb = strtoupper(trim($r_verb));
    $r_path = trim($r_path, '/');

    # method mismatch
    if ($r_verb !== strtoupper(trim($verb))) {
      return [null, null];
    }

    # match requested path against route, while picking out symbols
    $expr = preg_replace(
      ['@<([^:]+)>@U', '@<([^:]+)(:(.+))?>@U'],
      ['<$1:[^/]+>', '(?<$1>$3)'],
      trim($expr, '/')
    );

    # mismatch
    if (!preg_match('@^'.$expr.'$@', $r_path, $params)) {
      return [null, null];
    }

    # process matched route symbols
    $params = array_map('urldecode', array_intersect_key(
      array_slice($params, 1),
      array_flip(array_filter(array_keys($params), 'is_string'))
    ));

    return [$func, $params];
  };
}

# looks up matching callable for method + path
function lookup(array $routes, string $verb, string $path): array {

  # iterate over routes, and try to match the request
  foreach ($routes as $route) {
    list($func, $args) = $route($verb, $path);
    if ($func !== null) {
      return [$func, $args];
    }
  }

  # no matching route
  return [null, null];
}