Const statements

packages/typegpu/src/core/function/dualImpl.ts

@@ -5,16 +5,12 @@ import {
   type Snippet,
 } from '../../data/snippet.ts';
 import { inCodegenMode } from '../../execMode.ts';
-import { type FnArgsConversionHint, getOwnSnippet } from '../../types.ts';
+import { type FnArgsConversionHint, isKnownAtComptime } from '../../types.ts';
 import { setName } from '../../shared/meta.ts';
 import { $internal } from '../../shared/symbols.ts';
 import { tryConvertSnippet } from '../../tgsl/conversion.ts';
 import type { AnyData } from '../../data/dataTypes.ts';
 
-function isKnownAtComptime(value: unknown): boolean {
-  return typeof value !== 'string' && getOwnSnippet(value) === undefined;
-}
-
 export function createDualImpl<T extends (...args: never[]) => unknown>(
   jsImpl: T,
   gpuImpl: (...args: MapValueToSnippet<Parameters<T>>) => Snippet,
@@ -81,7 +77,7 @@ export function dualImpl<T extends (...args: never[]) => unknown>(
     }) as MapValueToSnippet<Parameters<T>>;
 
     if (
-      !options.noComptime && converted.every((s) => isKnownAtComptime(s.value))
+      !options.noComptime && converted.every((s) => isKnownAtComptime(s))
     ) {
       return snip(
         options.normalImpl(...converted.map((s) => s.value) as never[]),

packages/typegpu/src/tgsl/wgslGenerator.ts

@@ -19,7 +19,11 @@ import { getName } from '../shared/meta.ts';
 import { $internal } from '../shared/symbols.ts';
 import { pow } from '../std/numeric.ts';
 import { add, div, mul, sub } from '../std/operators.ts';
-import { type FnArgsConversionHint, isMarkedInternal } from '../types.ts';
+import {
+  type FnArgsConversionHint,
+  isKnownAtComptime,
+  isMarkedInternal,
+} from '../types.ts';
 import {
   convertStructValues,
   convertToCommonType,
@@ -818,6 +822,7 @@ ${this.ctx.pre}else ${alternate}`;
       // Assigning a reference to a `const` variable means we store the pointer
       // of the rhs.
       if (eq.ref !== undefined) {
+        // Referential
         if (stmtType === NODE.let) {
           const rhsStr = this.ctx.resolve(eq.value).value;
           const rhsTypeStr =
@@ -837,6 +842,15 @@ ${this.ctx.pre}else ${alternate}`;
         if (!wgsl.isPtr(dataType)) {
           dataType = ptrFn(concretize(dataType) as wgsl.StorableData);
         }
+      } else {
+        // Non-referential
+        if (
+          stmtType === NODE.const &&
+          !wgsl.isNaturallyRef(dataType) &&
+          isKnownAtComptime(eq)
+        ) {
+          varType = 'const';
+        }
       }
 
       const snippet = this.blockVariable(

packages/typegpu/src/types.ts

@@ -320,6 +320,11 @@ export function getOwnSnippet(value: unknown): Snippet | undefined {
   return (value as WithOwnSnippet)?.[$ownSnippet];
 }
 
+export function isKnownAtComptime(snippet: Snippet): boolean {
+  return typeof snippet.value !== 'string' &&
+    getOwnSnippet(snippet.value) === undefined;
+}
+
 export function isWgsl(value: unknown): value is Wgsl {
   return (
     typeof value === 'number' ||

packages/typegpu/tests/accessor.test.ts

@@ -163,7 +163,7 @@ describe('tgpu.accessor', () => {
         var color = vec3f(1, 0, 0);
         let color2 = (&redUniform);
         var color3 = getColor();
-        var colorX = 1;
+        const colorX = 1;
         var color2X = redUniform.x;
         var color3X = getColor().x;
       }"
@@ -180,7 +180,7 @@ describe('tgpu.accessor', () => {
 
     expect(asWgsl(main)).toMatchInlineSnapshot(`
       "fn main() {
-        var foo = 1f;
+        const foo = 1f;
       }"
     `);
   });

packages/typegpu/tests/derived.test.ts

@@ -146,7 +146,7 @@ describe('TgpuDerived', () => {
 
       fn func() {
         var pos = vec3f(2, 4, 6);
-        var posX = 2;
+        const posX = 2;
         let vel = (&boid.vel);
         var velX = boid.vel.x;
         let vel_ = (&boid.vel);

packages/typegpu/tests/examples/individual/3d-fish.test.ts

@@ -171,7 +171,7 @@ describe('3d fish example', () => {
           repulsion[i] = 1;
           var axisAquariumSize = (vec3f(10, 4, 10)[i] / 2f);
           var axisPosition = fishData.position[i];
-          var distance = 0.1;
+          const distance = 0.1;
           if ((axisPosition > (axisAquariumSize - distance))) {
             var str = (axisPosition - (axisAquariumSize - distance));
             wallRepulsion = (wallRepulsion - (str * repulsion));
@@ -184,7 +184,7 @@ describe('3d fish example', () => {
         if ((mouseRay_5.activated == 1)) {
           var proj = projectPointOnLine_8((&fishData.position), (&mouseRay_5.line));
           var diff = (fishData.position - proj);
-          var limit = 0.9;
+          const limit = 0.9;
           var str = (pow(2, clamp((limit - length(diff)), 0, limit)) - 1);
           rayRepulsion = (str * normalize(diff));
         }
@@ -218,8 +218,8 @@ describe('3d fish example', () => {
 
       fn applySinWave_4(index: u32, vertex: PosAndNormal_3, time: f32) -> PosAndNormal_3 {
         var a = -60.1;
-        var b = 0.8;
-        var c = 6.1;
+        const b = 0.8;
+        const c = 6.1;
         var posMod = vec3f();
         posMod.z = (sin((f32(index) + (((time / a) + vertex.position.x) / b))) / c);
         var coeff = (cos((f32(index) + (((time / a) + vertex.position.x) / b))) / c);

packages/typegpu/tests/examples/individual/box-raytracing.test.ts

@@ -168,7 +168,7 @@ describe('box raytracing example', () => {
         }
         var linear = (vec3f(1) / invColor);
         var srgb = linearToSrgb_12(linear);
-        var gamma = 2.2;
+        const gamma = 2.2;
         var corrected = pow(srgb, vec3f((1f / gamma)));
         if (intersectionFound) {
           return (min(density, 1) * vec4f(min(corrected, vec3f(1)), 1));

packages/typegpu/tests/examples/individual/fluid-double-buffering.test.ts

@@ -157,7 +157,7 @@ describe('fluid double buffering example', () => {
       }
 
       fn computeVelocity_8(x: i32, y: i32) -> vec2f {
-        var gravityCost = 0.5;
+        const gravityCost = 0.5;
         var neighborOffsets = array<vec2i, 4>(vec2i(0, 1), vec2i(0, -1), vec2i(1, 0), vec2i(-1, 0));
         var cell = getCell_6(x, y);
         var leastCost = cell.z;
@@ -216,7 +216,7 @@ describe('fluid double buffering example', () => {
       @group(0) @binding(3) var<uniform> sourceParams_18: item_19;
 
       fn getMinimumInFlow_17(x: i32, y: i32) -> f32 {
-        var gridSizeF = 256f;
+        const gridSizeF = 256f;
         var sourceRadius2 = max(1, (sourceParams_18.radius * gridSizeF));
         var sourcePos = vec2f((sourceParams_18.center.x * gridSizeF), (sourceParams_18.center.y * gridSizeF));
         if ((distance(vec2f(f32(x), f32(y)), sourcePos) < sourceRadius2)) {
@@ -324,7 +324,7 @@ describe('fluid double buffering example', () => {
       }
 
       fn computeVelocity_8(x: i32, y: i32) -> vec2f {
-        var gravityCost = 0.5;
+        const gravityCost = 0.5;
         var neighborOffsets = array<vec2i, 4>(vec2i(0, 1), vec2i(0, -1), vec2i(1, 0), vec2i(-1, 0));
         var cell = getCell_6(x, y);
         var leastCost = cell.z;
@@ -383,7 +383,7 @@ describe('fluid double buffering example', () => {
       @group(0) @binding(3) var<uniform> sourceParams_18: item_19;
 
       fn getMinimumInFlow_17(x: i32, y: i32) -> f32 {
-        var gridSizeF = 256f;
+        const gridSizeF = 256f;
         var sourceRadius2 = max(1, (sourceParams_18.radius * gridSizeF));
         var sourcePos = vec2f((sourceParams_18.center.x * gridSizeF), (sourceParams_18.center.y * gridSizeF));
         if ((distance(vec2f(f32(x), f32(y)), sourcePos) < sourceRadius2)) {
@@ -478,9 +478,9 @@ describe('fluid double buffering example', () => {
         var firstColor = vec4f(0.20000000298023224, 0.6000000238418579, 1, 1);
         var secondColor = vec4f(0.20000000298023224, 0.30000001192092896, 0.6000000238418579, 1);
         var thirdColor = vec4f(0.10000000149011612, 0.20000000298023224, 0.4000000059604645, 1);
-        var firstThreshold = 2f;
-        var secondThreshold = 10f;
-        var thirdThreshold = 20f;
+        const firstThreshold = 2f;
+        const secondThreshold = 10f;
+        const thirdThreshold = 20f;
         if (isInsideObstacle_6(x, y)) {
           return obstacleColor;
         }

packages/typegpu/tests/examples/individual/oklab.test.ts

@@ -136,7 +136,7 @@ describe('oklab example', () => {
       }
 
       fn findGamutIntersection_13(a: f32, b: f32, L1: f32, C1: f32, L0: f32, cusp: LC_12) -> f32 {
-        var FLT_MAX = 3.4028234663852886e+38f;
+        const FLT_MAX = 3.4028234663852886e+38f;
         var t = 0f;
         if (((((L1 - L0) * cusp.C) - ((cusp.L - L0) * C1)) <= 0)) {
           t = ((cusp.C * L0) / ((C1 * cusp.L) + (cusp.C * (L0 - L1))));
@@ -193,9 +193,9 @@ describe('oklab example', () => {
       }
 
       fn gamutClipAdaptiveL05_8(lab: vec3f) -> vec3f {
-        var alpha = 0.20000000298023224f;
+        const alpha = 0.20000000298023224f;
         var L = lab.x;
-        var eps = 1e-5;
+        const eps = 1e-5;
         var C = max(eps, length(lab.yz));
         var a_ = (lab.y / C);
         var b_ = (lab.z / C);

packages/typegpu/tests/examples/individual/ray-marching.test.ts

@@ -138,15 +138,15 @@ describe('ray-marching example', () => {
 
       fn getNormal_16(p: ptr<function, vec3f>) -> vec3f {
         var dist = getSceneDist_7(p).dist;
-        var e = 0.01;
+        const e = 0.01;
         var n = vec3f((getSceneDist_17(((*p) + vec3f(e, 0, 0))).dist - dist), (getSceneDist_17(((*p) + vec3f(0, e, 0))).dist - dist), (getSceneDist_17(((*p) + vec3f(0, 0, e))).dist - dist));
         return normalize(n);
       }
 
       fn getOrbitingLightPos_19(t: f32) -> vec3f {
-        var radius = 3f;
-        var height = 6f;
-        var speed = 1f;
+        const radius = 3f;
+        const height = 6f;
+        const speed = 1f;
         return vec3f((cos((t * speed)) * radius), (height + (sin((t * speed)) * radius)), 4);
       }
 

packages/typegpu/tests/examples/individual/stable-fluid.test.ts

@@ -240,14 +240,14 @@ describe('stable-fluid example', () => {
       }
 
       @fragment fn fragmentImageFn_3(input: fragmentImageFn_Input_7) -> @location(0) vec4f {
-        var pixelStep = 0.001953125f;
+        const pixelStep = 0.001953125f;
         var leftSample = textureSample(result_4, linSampler_5, vec2f((input.uv.x - pixelStep), input.uv.y)).x;
         var rightSample = textureSample(result_4, linSampler_5, vec2f((input.uv.x + pixelStep), input.uv.y)).x;
         var upSample = textureSample(result_4, linSampler_5, vec2f(input.uv.x, (input.uv.y + pixelStep))).x;
         var downSample = textureSample(result_4, linSampler_5, vec2f(input.uv.x, (input.uv.y - pixelStep))).x;
         var gradientX = (rightSample - leftSample);
         var gradientY = (upSample - downSample);
-        var distortStrength = 0.8;
+        const distortStrength = 0.8;
         var distortVector = vec2f(gradientX, gradientY);
         var distortedUV = (input.uv + (distortVector * vec2f(distortStrength, -distortStrength)));
         var outputColor = textureSample(background_6, linSampler_5, vec2f(distortedUV.x, (1 - distortedUV.y)));

packages/typegpu/tests/examples/individual/tgsl-parsing-test.test.ts

@@ -198,7 +198,7 @@ describe('tgsl parsing test example', () => {
 
       fn pointersTest_11() -> bool {
         var s = true;
-        var num = 0u;
+        const num = 0u;
         modifyNumFn_12((&num));
         s = (s && (num == 1));
         var vec = vec2f();

packages/typegpu/tests/numeric.test.ts

@@ -72,11 +72,11 @@ describe('TGSL', () => {
 
     expect(asWgsl(main)).toMatchInlineSnapshot(`
       "fn main() {
-        var f = 0f;
-        var h = 0h;
-        var i = 0i;
-        var u = 0u;
-        var b = false;
+        const f = 0f;
+        const h = 0h;
+        const i = 0i;
+        const u = 0u;
+        const b = false;
       }"
     `);
   });

packages/typegpu/tests/slot.test.ts

@@ -344,7 +344,7 @@ describe('tgpu.slot', () => {
 
       fn func() {
         var pos = vec3f(1, 2, 3);
-        var posX = 1;
+        const posX = 1;
         let vel = (&boid.vel);
         var velX = boid.vel.x;
         let vel_ = (&boid.vel);

packages/typegpu/tests/std/matrix/rotate.test.ts

@@ -16,7 +16,7 @@ describe('rotate', () => {
 
     expect(asWgsl(rotateFn)).toMatchInlineSnapshot(`
       "fn rotateFn() {
-        var angle = 4;
+        const angle = 4;
         var resultExpression = (mat4x4f(1, 0, 0, 0, 0, cos(angle), sin(angle), 0, 0, -sin(angle), cos(angle), 0, 0, 0, 0, 1) * mat4x4f(1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1));
       }"
     `);
@@ -30,17 +30,12 @@ describe('rotate', () => {
       const resultExpression = rotateY4(M, angle);
     });
 
-    expect(parseResolved({ rotateFn })).toBe(
-      parse(
-        `fn rotateFn() {
-          var angle = 4;
-          var resultExpression = (
-            mat4x4f(cos(angle), 0, -sin(angle), 0, 0, 1, 0, 0, sin(angle), 0, cos(angle), 0, 0, 0, 0, 1) *
-            mat4x4f(1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1)
-          );
-        }`,
-      ),
-    );
+    expect(asWgsl(rotateFn)).toMatchInlineSnapshot(`
+      "fn rotateFn() {
+        const angle = 4;
+        var resultExpression = (mat4x4f(cos(angle), 0, -sin(angle), 0, 0, 1, 0, 0, sin(angle), 0, cos(angle), 0, 0, 0, 0, 1) * mat4x4f(1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1));
+      }"
+    `);
   });
 
   it('generates correct WGSL for rotateZ4 with custom matrix', () => {
@@ -51,17 +46,12 @@ describe('rotate', () => {
       const resultExpression = rotateZ4(M, angle);
     });
 
-    expect(parseResolved({ rotateFn })).toBe(
-      parse(
-        `fn rotateFn() {
-          var angle = 4;
-          var resultExpression = (
-            mat4x4f(cos(angle), sin(angle), 0, 0, -sin(angle), cos(angle), 0, 0, 0, 0, 1, 0, 0, 0, 0, 1) *
-            mat4x4f(1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1)
-          );
-        }`,
-      ),
-    );
+    expect(asWgsl(rotateFn)).toMatchInlineSnapshot(`
+      "fn rotateFn() {
+        const angle = 4;
+        var resultExpression = (mat4x4f(cos(angle), sin(angle), 0, 0, -sin(angle), cos(angle), 0, 0, 0, 0, 1, 0, 0, 0, 0, 1) * mat4x4f(1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1));
+      }"
+    `);
   });
 
   it('rotates around X correctly', () => {