From 0e57ddd061abf20c91518b5e7e3611966483b0ba Mon Sep 17 00:00:00 2001
From: James Livesey <jamesliveg@gmail.com>
Date: Sat, 14 Sep 2024 14:53:26 +0100
Subject: [PATCH] Simplify position references to improve performance of `if`
 statements

---
 dist/libvoxel.h                | 11 +++++++++--
 src/executors.h                | 11 +++++++++--
 tools/vxbuild-js/statements.js | 27 +++++++++------------------
 tools/vxbuild/tokeniser.vxl    |  2 +-
 4 files changed, 28 insertions(+), 23 deletions(-)

diff --git a/dist/libvoxel.h b/dist/libvoxel.h
index 3761620..1c8a048 100644
--- a/dist/libvoxel.h
+++ b/dist/libvoxel.h
@@ -6154,9 +6154,16 @@ VOXEL_ERRORABLE voxel_stepExecutor(voxel_Executor* executor) {
 
             voxel_Thing* function = voxel_newFunctionPosRef(executor->context, referencedPosition);
 
-            VOXEL_MUST(voxel_setScopeItem(executor->scope, (voxel_Thing*)posRefKey.value, function));
+            voxel_Thing* posRefKeyValue = (voxel_Thing*)posRefKey.value;
+
+            if (posRefKeyValue->type != VOXEL_TYPE_NULL) {
+                VOXEL_MUST(voxel_setScopeItem(executor->scope, (voxel_Thing*)posRefKey.value, function));
+                VOXEL_MUST(voxel_unreferenceThing(executor->context, function));
+            } else {
+                VOXEL_MUST(voxel_pushOntoList(executor->context, executor->valueStack, function));
+            }
+
             VOXEL_MUST(voxel_unreferenceThing(executor->context, (voxel_Thing*)posRefKey.value));
-            VOXEL_MUST(voxel_unreferenceThing(executor->context, function));
 
             break;
         }
diff --git a/src/executors.h b/src/executors.h
index 7916009..679a6f4 100644
--- a/src/executors.h
+++ b/src/executors.h
@@ -404,9 +404,16 @@ VOXEL_ERRORABLE voxel_stepExecutor(voxel_Executor* executor) {
 
             voxel_Thing* function = voxel_newFunctionPosRef(executor->context, referencedPosition);
 
-            VOXEL_MUST(voxel_setScopeItem(executor->scope, (voxel_Thing*)posRefKey.value, function));
+            voxel_Thing* posRefKeyValue = (voxel_Thing*)posRefKey.value;
+
+            if (posRefKeyValue->type != VOXEL_TYPE_NULL) {
+                VOXEL_MUST(voxel_setScopeItem(executor->scope, (voxel_Thing*)posRefKey.value, function));
+                VOXEL_MUST(voxel_unreferenceThing(executor->context, function));
+            } else {
+                VOXEL_MUST(voxel_pushOntoList(executor->context, executor->valueStack, function));
+            }
+
             VOXEL_MUST(voxel_unreferenceThing(executor->context, (voxel_Thing*)posRefKey.value));
-            VOXEL_MUST(voxel_unreferenceThing(executor->context, function));
 
             break;
         }
diff --git a/tools/vxbuild-js/statements.js b/tools/vxbuild-js/statements.js
index 8c44349..7cbe697 100644
--- a/tools/vxbuild-js/statements.js
+++ b/tools/vxbuild-js/statements.js
@@ -248,30 +248,21 @@ export class IfStatementNode extends ast.AstNode {
         ) : codeGen.bytes();
 
         var skipFalseCode = this.skipFalseSymbol ? codeGen.join(
-            this.skipFalseSymbol.generateCode(options),
-            codeGen.bytes(codeGen.vxcTokens.GET, codeGen.vxcTokens.JUMP)
+            codeGen.bytes(codeGen.vxcTokens.NULL, codeGen.vxcTokens.POS_REF_FORWARD),
+            codeGen.int32(isFalseCode.length + 1),
+            codeGen.bytes(codeGen.vxcTokens.JUMP)
+
         ) : codeGen.bytes(); // Not necessary if we do not need to skip true statement
 
         var skipTrueCode = codeGen.join(
-            this.skipTrueSymbol.generateCode(options),
-            codeGen.bytes(codeGen.vxcTokens.GET, codeGen.vxcTokens.JUMP_IF_TRUTHY)
-        );
-
-        var skipFalseDefinitionCode = this.skipFalseSymbol ? codeGen.join(
-            this.skipFalseSymbol.generateCode(options),
-            codeGen.bytes(codeGen.vxcTokens.POS_REF_FORWARD),
-            codeGen.int32(notConditionCode.length + skipTrueCode.length + isTrueCode.length + skipFalseCode.length + isFalseCode.length)
-        ) : codeGen.bytes();
-
-        var skipTrueDefinitionCode = codeGen.join(
-            this.skipTrueSymbol.generateCode(options),
-            codeGen.bytes(codeGen.vxcTokens.POS_REF_FORWARD),
-            codeGen.int32(skipFalseDefinitionCode.length + notConditionCode.length + skipTrueCode.length + isTrueCode.length + skipFalseCode.length)
+            codeGen.bytes(codeGen.vxcTokens.NULL, codeGen.vxcTokens.POS_REF_FORWARD),
+            codeGen.int32(isTrueCode.length + skipFalseCode.length + isFalseCode.length + 1),
+            codeGen.bytes(codeGen.vxcTokens.JUMP_IF_TRUTHY)
         );
 
         return codeGen.join(
-            skipTrueDefinitionCode,
-            skipFalseDefinitionCode,
+            // skipTrueDefinitionCode,
+            // skipFalseDefinitionCode,
             notConditionCode,
             skipTrueCode,
             isTrueCode,
diff --git a/tools/vxbuild/tokeniser.vxl b/tools/vxbuild/tokeniser.vxl
index 11f4536..1767075 100644
--- a/tools/vxbuild/tokeniser.vxl
+++ b/tools/vxbuild/tokeniser.vxl
@@ -413,7 +413,7 @@ export function tokenise(sourceContainer) {
             (
                 (currentByte >= Byte("a") &&& currentByte <= Byte("z")) |||
                 (currentByte >= Byte("A") &&& currentByte <= Byte("Z")) |||
-                currentByte == Byte("_") || currentByte == Byte("$")
+                currentByte == Byte("_") ||| currentByte == Byte("$")
             ) && matchIdentifier()
         ) {
             if (KEYWORDS.contains(matchedString)) {