added function for http requests

README.md

@@ -195,7 +195,7 @@ Name    | Example | Example result | Description
 
 ### Database functions
 
-This is just a simple wrapper for [PDO](https://www.php.net/manual/en/book.pdo.php).
+This is a simple wrapper for [PDO](https://www.php.net/manual/en/book.pdo.php).
 
 Name        | Example | Example result | Description
 ----------- | ------- | -------------- | -----------
@@ -207,6 +207,14 @@ db-trans    | `(db-trans d)` | `true` | Start a transaction.
 db-commit   | `(db-commit d)` | `true` | Commit a transaction.
 db-rollback | `(db-rollback d)` | `true` | Roll back a transaction.
 
+### Http functions
+
+This is a simple wrapper for [cURL](https://www.php.net/manual/en/book.curl.php).
+
+Name        | Example | Example result | Description
+----------- | ------- | -------------- | -----------
+http        | `(http "POST" "http://example.com/" (to-json {"key":"value"}) {"Content-Type":"application/json"})` | `{"status":200 "body":"" "headers":{}}` | Perform a HTTP request. First argument is the HTTP method, second is URL, third is request body and fourth is headers as a hash-map. The function returns a hash-map which contains keys `status`, `body` and `headers`.
+
 ### IO functions
 
 Name    | Example | Example result | Description

src/Lib/Http.php

@@ -0,0 +1,72 @@
+<?php
+namespace MadLisp\Lib;
+
+use MadLisp\CoreFunc;
+use MadLisp\Env;
+use MadLisp\Hash;
+use MadLisp\MadLispException;
+
+class Http implements ILib
+{
+    public function register(Env $env): void
+    {
+        $env->set('http', new CoreFunc('http', 'Perform a HTTP request.', 2, 4,
+            function (string $method, string $url, ?string $requestBody = null, ?Hash $requestHeaders = null) {
+                $ch = curl_init($url);
+
+                $method = strtoupper($method);
+                if ($method == 'HEAD') {
+                    curl_setopt($ch, CURLOPT_NOBODY, true);
+                } elseif ($method != 'GET') {
+                    curl_setopt($ch, CURLOPT_CUSTOMREQUEST, $method);
+                }
+
+                if ($requestBody !== null) {
+                    curl_setopt($ch, CURLOPT_POSTFIELDS, $requestBody);
+                    curl_setopt($ch, CURLOPT_POSTREDIR, 3);
+                }
+
+                curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
+                curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
+
+                if ($requestHeaders !== null) {
+                    $h = [];
+                    foreach ($requestHeaders->getData() as $key => $val) {
+                        $h[] = "$key: $val";
+                    }
+                    curl_setopt($ch, CURLOPT_HTTPHEADER, $h);
+                }
+
+                // for debugging
+                // curl_setopt($ch, CURLOPT_VERBOSE, true);
+
+                $responseHeaders = [];
+                curl_setopt($ch, CURLOPT_HEADERFUNCTION, function ($ch, $header) use (&$responseHeaders) {
+                    $parts = explode(':', $header);
+                    if (count($parts) == 2) {
+                        $key = trim($parts[0]);
+                        $val = trim($parts[1]);
+                        $responseHeaders[$key] = $val;
+                    }
+                    return strlen($header);
+                });
+
+                $responseBody = @curl_exec($ch);
+
+                if (curl_errno($ch) !== 0) {
+                    throw new MadLispException('HTTP error: ' . curl_error($ch));
+                }
+
+                $status = curl_getinfo($ch, CURLINFO_HTTP_CODE);
+
+                curl_close($ch);
+
+                return new Hash([
+                    'status' => $status,
+                    'body' => $responseBody,
+                    'headers' => new Hash($responseHeaders)
+                ]);
+            }
+        ));
+    }
+}

src/LispFactory.php

@@ -45,6 +45,7 @@ class LispFactory
         (new Lib\Collections())->register($env);
         (new Lib\Compare())->register($env);
         (new Lib\Database())->register($env);
+        (new Lib\Http())->register($env);
         (new Lib\IO())->register($env);
         (new Lib\Json())->register($env);
         (new Lib\Math())->register($env);