Install psalm as dev, sync scripts updates

vendor/felixfbecker/language-server-protocol/src/SignatureHelp.php

@@ -0,0 +1,61 @@
+<?php
+
+namespace LanguageServerProtocol;
+
+/**
+ * Signature help represents the signature of something
+ * callable. There can be multiple signature but only one
+ * active and only one active parameter.
+ */
+class SignatureHelp
+{
+    /**
+     * One or more signatures. If no signatures are available the signature help
+     * request should return `null`.
+     *
+     * @var SignatureInformation[]|null
+     */
+    public $signatures;
+
+    /**
+     * The active signature. If omitted or the value lies outside the
+     * range of `signatures` the value defaults to zero or is ignore if
+     * the `SignatureHelp` as no signatures.
+     *
+     * Whenever possible implementors should make an active decision about
+     * the active signature and shouldn't rely on a default value.
+     *
+     * In future version of the protocol this property might become
+     * mandatory to better express this.
+     *
+     * @var int|null
+     */
+    public $activeSignature;
+
+    /**
+     * The active parameter of the active signature. If omitted or the value
+     * lies outside the range of `signatures[activeSignature].parameters`
+     * defaults to 0 if the active signature has parameters. If
+     * the active signature has no parameters it is ignored.
+     * In future version of the protocol this property might become
+     * mandatory to better express the active parameter if the
+     * active signature does have any.
+     *
+     * @var int|null
+     */
+    public $activeParameter;
+
+    /**
+     * Create a SignatureHelp
+     *
+     * @param SignatureInformation[]|null $signatures      List of signature information
+     * @param int|null               $activeSignature The active signature, zero based
+     * @param int|null               $activeParameter The active parameter, zero based
+     */
+    public function __construct(array $signatures = null, $activeSignature = null, int $activeParameter = null)
+    {
+        $this->signatures = $signatures;
+        $this->activeSignature = $activeSignature;
+        $this->activeParameter = $activeParameter;
+    }
+}