From 4786fe173ce690eb176f847e89b0456df7d44596 Mon Sep 17 00:00:00 2001
From: Felix Becker <felix.b@outlook.com>
Date: Sat, 8 Oct 2016 13:22:34 +0200
Subject: [PATCH] Decorate all nodes with parent, sibling references

---
 src/NodeVisitors/ReferencesAdder.php | 41 ++++++++++++++++++++++++++++
 src/PhpDocument.php                  | 18 +++++++++---
 2 files changed, 55 insertions(+), 4 deletions(-)
 create mode 100644 src/NodeVisitors/ReferencesAdder.php

diff --git a/src/NodeVisitors/ReferencesAdder.php b/src/NodeVisitors/ReferencesAdder.php
new file mode 100644
index 0000000..0d62a80
--- /dev/null
+++ b/src/NodeVisitors/ReferencesAdder.php
@@ -0,0 +1,41 @@
+<?php
+declare(strict_types = 1);
+
+namespace LanguageServer\NodeVisitors;
+
+use PhpParser\{NodeVisitorAbstract, Node};
+use LanguageServer\Protocol\{SymbolInformation, SymbolKind, Range, Position, Location};
+
+/**
+ * Decorates all nodes with parent and sibling references (similar to DOM nodes)
+ */
+class ReferencesAdder extends NodeVisitorAbstract
+{
+    /**
+     * @var Node[]
+     */
+    private $stack = [];
+
+    /**
+     * @var Node
+     */
+    private $previous;
+
+    public function enterNode(Node $node)
+    {
+        if (!empty($this->stack)) {
+            $node->setAttribute('parentNode', end($this->stack));
+        }
+        if (isset($this->previous) && $this->previous->getAttribute('parentNode') === $node->getAttribute('parentNode')) {
+            $node->setAttribute('previousSibling', $this->previous);
+            $this->previous->setAttribute('nextSibling', $node);
+        }
+        $this->stack[] = $node;
+    }
+
+    public function leaveNode(Node $node)
+    {
+        $this->previous = $node;
+        array_pop($this->stack);
+    }
+}
diff --git a/src/PhpDocument.php b/src/PhpDocument.php
index e394bc2..ac46a85 100644
--- a/src/PhpDocument.php
+++ b/src/PhpDocument.php
@@ -4,7 +4,7 @@ declare(strict_types = 1);
 namespace LanguageServer;
 
 use LanguageServer\Protocol\{Diagnostic, DiagnosticSeverity, Range, Position, SymbolKind, TextEdit};
-use LanguageServer\NodeVisitors\{SymbolFinder, ColumnCalculator};
+use LanguageServer\NodeVisitors\{ReferencesAdder, SymbolFinder, ColumnCalculator};
 use PhpParser\{Error, Comment, Node, ParserFactory, NodeTraverser, Lexer, Parser};
 use PhpParser\PrettyPrinter\Standard as PrettyPrinter;
 use PhpParser\NodeVisitor\NameResolver;
@@ -138,13 +138,23 @@ class PhpDocument
         // $stmts can be null in case of a fatal parsing error
         if ($stmts) {
             $traverser = new NodeTraverser;
-            $finder = new SymbolFinder($this->uri);
+
+            // Resolve aliased names to FQNs
             $traverser->addVisitor(new NameResolver);
+
+            // Add parentNode, previousSibling, nextSibling attributes
+            $traverser->addVisitor(new ReferencesAdder);
+
+            // Add column attributes to nodes
             $traverser->addVisitor(new ColumnCalculator($this->content));
-            $traverser->addVisitor($finder);
+
+            // Collect all symbols
+            $symbolFinder = new SymbolFinder($this->uri);
+            $traverser->addVisitor($symbolFinder);
+
             $traverser->traverse($stmts);
 
-            $this->symbols = $finder->symbols;
+            $this->symbols = $symbolFinder->symbols;
         }
 
         return $stmts;