Rename escape function

Renamed constants.php to functions.php since it now contains a function.

composer.json

@@ -31,7 +31,7 @@
         "psr-4": {
             "Amp\\Process\\": "lib"
         },
-        "files": ["lib/constants.php"]
+        "files": ["lib/functions.php"]
     },
     "autoload-dev": {
         "psr-4": {

lib/Process.php

@@ -46,7 +46,7 @@ final class Process
     public function __construct($command, string $cwd = null, array $env = [], array $options = [])
     {
         $command = \is_array($command)
-            ? \implode(" ", \array_map(__NAMESPACE__ . "\\escape_arg", $command))
+            ? \implode(" ", \array_map(__NAMESPACE__ . "\\escapeArguments", $command))
             : (string) $command;
 
         $cwd = $cwd ?? "";

lib/constants.php

@@ -1,20 +0,0 @@
-<?php
-
-namespace Amp\Process;
-
-const BIN_DIR = __DIR__ . DIRECTORY_SEPARATOR . '..' . DIRECTORY_SEPARATOR . 'bin';
-const IS_WINDOWS = (PHP_OS & "\xDF\xDF\xDF") === 'WIN';
-
-if (IS_WINDOWS) {
-    function escape_arg($arg)
-    {
-        return '"' . \preg_replace_callback('(\\\\*("|$))', function ($m) {
-            return \str_repeat('\\', \strlen($m[0])) . $m[0];
-        }, $arg) . '"';
-    }
-} else {
-    function escape_arg($arg)
-    {
-        return \escapeshellarg($arg);
-    }
-}

lib/functions.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace Amp\Process;
+
+const BIN_DIR = __DIR__ . DIRECTORY_SEPARATOR . '..' . DIRECTORY_SEPARATOR . 'bin';
+const IS_WINDOWS = (PHP_OS & "\xDF\xDF\xDF") === 'WIN';
+
+if (IS_WINDOWS) {
+    /**
+     * Escapes the command argument for safe inclusion into a Windows command string.
+     *
+     * @param string $arg
+     *
+     * @return string
+     */
+    function escapeArguments(string $arg): string
+    {
+        return '"' . \preg_replace_callback('(\\\\*("|$))', function (array $m): string {
+            return \str_repeat('\\', \strlen($m[0])) . $m[0];
+        }, $arg) . '"';
+    }
+} else {
+    /**
+     * Escapes the command argument for safe inclusion into a Posix shell command string.
+     *
+     * @param string $arg
+     *
+     * @return string
+     */
+    function escapeArguments(string $arg): string
+    {
+        return \escapeshellarg($arg);
+    }
+}