From baa1a68b53f36f41271142b24887ba44c137be3a Mon Sep 17 00:00:00 2001
From: Robin Voetter <robin@voetter.nl>
Date: Mon, 15 Jun 2020 13:50:07 +0200
Subject: [PATCH] Remove declarations in an order-preserving way

---
 generator/generator.zig | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/generator/generator.zig b/generator/generator.zig
index 558f4e6..2a5280b 100644
--- a/generator/generator.zig
+++ b/generator/generator.zig
@@ -132,22 +132,22 @@ const DeclarationResolver = struct {
             }
         }
 
-        // Swap-remove all declarations that are not required.
-        // Some declarations may exist in `self.declarations` that do not exit in
-        // `self.registry.decls`, these are mostly macros and other stuff not parsed.
-        var i: usize = 0;
-        var count = self.registry.decls.len;
-        while (i < count) {
-            const decl = self.registry.decls[i];
+        // Remove all declarations that are not required.
+        //  Some declarations may exist in `self.declarations` that do not exit in
+        // `self.registry.decls`, these are mostly macros and other stuff not pa
+        var read_index: usize = 0;
+        var write_index: usize = 0;
+        while (read_index < self.registry.decls.len) {
+            const decl = self.registry.decls[read_index];
             if (self.declarations.contains(decl.name)) {
-                i += 1;
-            } else {
-                count -= 1;
-                self.registry.decls[i] = self.registry.decls[count];
+                self.registry.decls[write_index] = decl;
+                write_index += 1;
             }
+
+            read_index += 1;
         }
 
-        self.registry.decls = self.reg_arena.shrink(self.registry.decls, count);
+        self.registry.decls = self.reg_arena.shrink(self.registry.decls, write_index);
     }
 };