diff --git a/app/gui2/e2e/main.ts b/app/gui2/e2e/main.ts
index 2ad001b64f7..c3fa5c8f7e1 100644
--- a/app/gui2/e2e/main.ts
+++ b/app/gui2/e2e/main.ts
@@ -4,8 +4,8 @@ import { createApp, ref } from 'vue'
 import '../src/assets/base.css'
 import { provideGuiConfig } from '../src/providers/guiConfig'
 import { provideVisualizationConfig } from '../src/providers/visualizationConfig'
+import { Vec2 } from '../src/util/data/vec2'
 import { MockTransport, MockWebSocket } from '../src/util/net'
-import { Vec2 } from '../src/util/vec2'
 import MockApp from './MockApp.vue'
 import { mockDataHandler, mockLSHandler } from './mockEngine'
 
diff --git a/app/gui2/scripts/generateIconMetadata.js b/app/gui2/scripts/generateIconMetadata.js
index fd6a7f2d338..07b9a5794ae 100644
--- a/app/gui2/scripts/generateIconMetadata.js
+++ b/app/gui2/scripts/generateIconMetadata.js
@@ -13,8 +13,18 @@ await fs.writeFile(
   `\
 // Generated by \`scripts/generateIcons.js\`.
 // Please run \`npm run generate\` to regenerate this file whenever \`icons.svg\` is changed.
+import iconNames from '@/util/iconList.json'
+
 export type Icon =
 ${iconNames?.map((name) => `  | '${name}'`).join('\n')}
+
+export { iconNames }
+
+const iconNamesSet = new Set(iconNames)
+
+export function isIconName(value: string): value is Icon {
+  return iconNamesSet.has(value)
+}
 `,
 )
 console.info('Done.')
diff --git a/app/gui2/src/components/CodeEditor.vue b/app/gui2/src/components/CodeEditor.vue
index f1da0217132..3d35218148c 100644
--- a/app/gui2/src/components/CodeEditor.vue
+++ b/app/gui2/src/components/CodeEditor.vue
@@ -1,16 +1,16 @@
 <script setup lang="ts">
+import type { Diagnostic, Highlighter } from '@/components/CodeEditor/codemirror'
+import { usePointer } from '@/composables/events'
 import { useGraphStore } from '@/stores/graph'
 import { useProjectStore } from '@/stores/project'
 import { useSuggestionDbStore } from '@/stores/suggestionDatabase'
 import { useAutoBlur } from '@/util/autoBlur'
-import type { Diagnostic, Highlighter } from '@/util/codemirror'
-import { usePointer } from '@/util/events'
-import { chain } from '@/util/iterable'
+import { chain } from '@/util/data/iterable'
+import { unwrap } from '@/util/data/result'
+import { qnJoin, tryQualifiedName } from '@/util/qualifiedName'
 import { useLocalStorage } from '@vueuse/core'
 import { rangeEncloses, type ExprId } from 'shared/yjsModel'
 import { computed, onMounted, ref, watch, watchEffect } from 'vue'
-import { qnJoin, tryQualifiedName } from '../util/qualifiedName'
-import { unwrap } from '../util/result'
 
 // Use dynamic imports to aid code splitting. The codemirror dependency is quite large.
 const {
@@ -30,7 +30,7 @@ const {
   forceLinting,
   lsDiagnosticsToCMDiagnostics,
   hoverTooltip,
-} = await import('@/util/codemirror')
+} = await import('@/components/CodeEditor/codemirror')
 
 const projectStore = useProjectStore()
 const graphStore = useGraphStore()
diff --git a/app/gui2/src/util/codemirror.ts b/app/gui2/src/components/CodeEditor/codemirror.ts
similarity index 100%
rename from app/gui2/src/util/codemirror.ts
rename to app/gui2/src/components/CodeEditor/codemirror.ts
diff --git a/app/gui2/src/components/ComponentBrowser.vue b/app/gui2/src/components/ComponentBrowser.vue
index 4d32372a69a..a6b223cd57e 100644
--- a/app/gui2/src/components/ComponentBrowser.vue
+++ b/app/gui2/src/components/ComponentBrowser.vue
@@ -2,26 +2,26 @@
 import { componentBrowserBindings } from '@/bindings'
 import { makeComponentList, type Component } from '@/components/ComponentBrowser/component'
 import { Filtering } from '@/components/ComponentBrowser/filtering'
+import { useComponentBrowserInput, type Usage } from '@/components/ComponentBrowser/input'
 import { default as DocumentationPanel } from '@/components/DocumentationPanel.vue'
+import GraphVisualization from '@/components/GraphEditor/GraphVisualization.vue'
 import SvgIcon from '@/components/SvgIcon.vue'
 import ToggleIcon from '@/components/ToggleIcon.vue'
+import { useApproach } from '@/composables/animation'
+import { useEvent, useResizeObserver } from '@/composables/events'
+import type { useNavigator } from '@/composables/navigator'
 import { useGraphStore } from '@/stores/graph'
 import type { RequiredImport } from '@/stores/graph/imports'
 import { useProjectStore } from '@/stores/project'
 import { groupColorStyle, useSuggestionDbStore } from '@/stores/suggestionDatabase'
 import { SuggestionKind, type SuggestionEntry } from '@/stores/suggestionDatabase/entry'
 import type { VisualizationDataSource } from '@/stores/visualization'
-import { useApproach } from '@/util/animation'
-import { tryGetIndex } from '@/util/array'
-import { useEvent, useResizeObserver } from '@/util/events'
-import type { useNavigator } from '@/util/navigator'
-import type { Opt } from '@/util/opt'
-import { allRanges } from '@/util/range'
-import { Vec2 } from '@/util/vec2'
+import { tryGetIndex } from '@/util/data/array'
+import type { Opt } from '@/util/data/opt'
+import { allRanges } from '@/util/data/range'
+import { Vec2 } from '@/util/data/vec2'
 import type { SuggestionId } from 'shared/languageServerTypes/suggestions'
 import { computed, nextTick, onMounted, ref, watch, type ComputedRef, type Ref } from 'vue'
-import { useComponentBrowserInput, type Usage } from './ComponentBrowser/input'
-import GraphVisualization from './GraphEditor/GraphVisualization.vue'
 
 const ITEM_SIZE = 32
 const TOP_BAR_HEIGHT = 32
diff --git a/app/gui2/src/components/ComponentBrowser/__tests__/component.test.ts b/app/gui2/src/components/ComponentBrowser/__tests__/component.test.ts
index f38dc9f9b08..b393b946e72 100644
--- a/app/gui2/src/components/ComponentBrowser/__tests__/component.test.ts
+++ b/app/gui2/src/components/ComponentBrowser/__tests__/component.test.ts
@@ -16,7 +16,7 @@ import {
   makeStaticMethod,
   type SuggestionEntry,
 } from '@/stores/suggestionDatabase/entry'
-import { allRanges } from '@/util/range'
+import { allRanges } from '@/util/data/range'
 import shuffleSeed from 'shuffle-seed'
 
 test.each([
diff --git a/app/gui2/src/components/ComponentBrowser/__tests__/filtering.test.ts b/app/gui2/src/components/ComponentBrowser/__tests__/filtering.test.ts
index 00eea61c923..5c2fbda5d2e 100644
--- a/app/gui2/src/components/ComponentBrowser/__tests__/filtering.test.ts
+++ b/app/gui2/src/components/ComponentBrowser/__tests__/filtering.test.ts
@@ -11,8 +11,8 @@ import {
   makeStaticMethod,
   makeType,
 } from '@/stores/suggestionDatabase/entry'
+import { unwrap } from '@/util/data/result'
 import { tryQualifiedName, type QualifiedName } from '@/util/qualifiedName'
-import { unwrap } from '@/util/result'
 
 test.each([
   { ...makeModuleMethod('Standard.Base.Data.read'), groupIndex: 0 },
diff --git a/app/gui2/src/components/ComponentBrowser/__tests__/input.test.ts b/app/gui2/src/components/ComponentBrowser/__tests__/input.test.ts
index f6a276e1a01..d238e0b4db6 100644
--- a/app/gui2/src/components/ComponentBrowser/__tests__/input.test.ts
+++ b/app/gui2/src/components/ComponentBrowser/__tests__/input.test.ts
@@ -1,3 +1,4 @@
+import { useComponentBrowserInput } from '@/components/ComponentBrowser/input'
 import { GraphDb } from '@/stores/graph/graphDatabase'
 import type { RequiredImport } from '@/stores/graph/imports'
 import { ComputedValueRegistry } from '@/stores/project/computedValueRegistry'
@@ -13,11 +14,10 @@ import {
   makeType,
   type SuggestionEntry,
 } from '@/stores/suggestionDatabase/entry'
+import { unwrap } from '@/util/data/result'
 import { tryIdentifier, tryQualifiedName } from '@/util/qualifiedName'
-import { unwrap } from '@/util/result'
 import type { ExprId } from 'shared/yjsModel'
 import { expect, test } from 'vitest'
-import { useComponentBrowserInput } from '../input'
 
 test.each([
   ['', 0, { type: 'insert', position: 0 }, {}],
diff --git a/app/gui2/src/components/ComponentBrowser/__tests__/placement.test.ts b/app/gui2/src/components/ComponentBrowser/__tests__/placement.test.ts
index 0045eb91a4f..e4a1cbb927e 100644
--- a/app/gui2/src/components/ComponentBrowser/__tests__/placement.test.ts
+++ b/app/gui2/src/components/ComponentBrowser/__tests__/placement.test.ts
@@ -5,10 +5,10 @@ import {
   type Environment,
   type Placement,
 } from '@/components/ComponentBrowser/placement'
-import * as iterable from '@/util/iterable'
-import { chain, map, range } from '@/util/iterable'
-import { Rect } from '@/util/rect'
-import { Vec2 } from '@/util/vec2'
+import * as iterable from '@/util/data/iterable'
+import { chain, map, range } from '@/util/data/iterable'
+import { Rect } from '@/util/data/rect'
+import { Vec2 } from '@/util/data/vec2'
 import { fc, test as fcTest } from '@fast-check/vitest'
 import { describe, expect, test, vi } from 'vitest'
 
diff --git a/app/gui2/src/components/ComponentBrowser/component.ts b/app/gui2/src/components/ComponentBrowser/component.ts
index 65631342106..9c5d68d63b1 100644
--- a/app/gui2/src/components/ComponentBrowser/component.ts
+++ b/app/gui2/src/components/ComponentBrowser/component.ts
@@ -6,11 +6,11 @@ import {
   type SuggestionId,
 } from '@/stores/suggestionDatabase/entry'
 import { compareOpt } from '@/util/compare'
+import { isSome } from '@/util/data/opt'
+import { Range } from '@/util/data/range'
 import { displayedIconOf } from '@/util/getIconName'
 import type { Icon } from '@/util/iconName'
-import { isSome } from '@/util/opt'
 import { qnIsTopElement, qnLastSegmentIndex } from '@/util/qualifiedName'
-import { Range } from '@/util/range'
 
 interface ComponentLabel {
   label: string
diff --git a/app/gui2/src/components/ComponentBrowser/filtering.ts b/app/gui2/src/components/ComponentBrowser/filtering.ts
index 2b6e2dec9b0..05d84cd6c11 100644
--- a/app/gui2/src/components/ComponentBrowser/filtering.ts
+++ b/app/gui2/src/components/ComponentBrowser/filtering.ts
@@ -3,9 +3,9 @@ import {
   type SuggestionEntry,
   type Typename,
 } from '@/stores/suggestionDatabase/entry'
-import type { Opt } from '@/util/opt'
+import type { Opt } from '@/util/data/opt'
+import { Range } from '@/util/data/range'
 import { qnIsTopElement, qnParent, type QualifiedName } from '@/util/qualifiedName'
-import { Range } from '@/util/range'
 
 export type SelfArg =
   | {
diff --git a/app/gui2/src/components/ComponentBrowser/placement.ts b/app/gui2/src/components/ComponentBrowser/placement.ts
index af1b12bb163..de61b2e992c 100644
--- a/app/gui2/src/components/ComponentBrowser/placement.ts
+++ b/app/gui2/src/components/ComponentBrowser/placement.ts
@@ -1,7 +1,7 @@
 import { bail } from '@/util/assert'
-import { Rect } from '@/util/rect'
+import { Rect } from '@/util/data/rect'
+import { Vec2 } from '@/util/data/vec2'
 import theme from '@/util/theme.json'
-import { Vec2 } from '@/util/vec2'
 
 export interface Environment {
   screenBounds: Rect
diff --git a/app/gui2/src/components/DocumentationPanel.vue b/app/gui2/src/components/DocumentationPanel.vue
index c805b10830d..5bf5dc896e6 100644
--- a/app/gui2/src/components/DocumentationPanel.vue
+++ b/app/gui2/src/components/DocumentationPanel.vue
@@ -11,9 +11,9 @@ import type { Docs, FunctionDocs, Sections, TypeDocs } from '@/components/Docume
 import { lookupDocumentation, placeholder } from '@/components/DocumentationPanel/ir'
 import { groupColorStyle, useSuggestionDbStore } from '@/stores/suggestionDatabase'
 import type { SuggestionId } from '@/stores/suggestionDatabase/entry'
-import { tryGetIndex } from '@/util/array'
+import { tryGetIndex } from '@/util/data/array'
+import { type Opt } from '@/util/data/opt'
 import type { Icon as IconName } from '@/util/iconName'
-import { type Opt } from '@/util/opt'
 import type { QualifiedName } from '@/util/qualifiedName'
 import { qnSegments, qnSlice } from '@/util/qualifiedName'
 import { computed, watch } from 'vue'
diff --git a/app/gui2/src/components/ExecutionModeSelector.vue b/app/gui2/src/components/ExecutionModeSelector.vue
index 9ded68061ce..56cea97a087 100644
--- a/app/gui2/src/components/ExecutionModeSelector.vue
+++ b/app/gui2/src/components/ExecutionModeSelector.vue
@@ -1,6 +1,6 @@
 <script setup lang="ts">
 import SvgIcon from '@/components/SvgIcon.vue'
-import { useEvent } from '@/util/events'
+import { useEvent } from '@/composables/events'
 import { ref } from 'vue'
 
 const props = defineProps<{ modes: string[]; modelValue: string }>()
diff --git a/app/gui2/src/components/GraphEditor.vue b/app/gui2/src/components/GraphEditor.vue
index 076dd5a8b76..2ffedb30616 100644
--- a/app/gui2/src/components/GraphEditor.vue
+++ b/app/gui2/src/components/GraphEditor.vue
@@ -7,14 +7,15 @@ import {
   nonDictatedPlacement,
   previousNodeDictatedPlacement,
   type Environment,
-} from '@/components/ComponentBrowser/placement.ts'
+} from '@/components/ComponentBrowser/placement'
 import GraphEdges from '@/components/GraphEditor/GraphEdges.vue'
 import GraphNodes from '@/components/GraphEditor/GraphNodes.vue'
 import { Uploader, uploadedExpression } from '@/components/GraphEditor/upload'
 import GraphMouse from '@/components/GraphMouse.vue'
 import PlusButton from '@/components/PlusButton.vue'
 import TopBar from '@/components/TopBar.vue'
-import { useDoubleClick } from '@/composables/doubleClick.ts'
+import { useDoubleClick } from '@/composables/doubleClick'
+import { keyboardBusy, keyboardBusyExceptIn, useEvent } from '@/composables/events'
 import { provideGraphNavigator } from '@/providers/graphNavigator'
 import { provideGraphSelection } from '@/providers/graphSelection'
 import { provideInteractionHandler, type Interaction } from '@/providers/interactionHandler'
@@ -24,12 +25,11 @@ import type { RequiredImport } from '@/stores/graph/imports'
 import { useProjectStore } from '@/stores/project'
 import { groupColorVar, useSuggestionDbStore } from '@/stores/suggestionDatabase'
 import { colorFromString } from '@/util/colors'
-import { keyboardBusy, keyboardBusyExceptIn, useEvent } from '@/util/events'
-import { qnLastSegment, tryQualifiedName } from '@/util/qualifiedName.ts'
-import { Rect } from '@/util/rect.ts'
-import { Vec2 } from '@/util/vec2'
+import { Rect } from '@/util/data/rect'
+import { Vec2 } from '@/util/data/vec2'
+import { qnLastSegment, tryQualifiedName } from '@/util/qualifiedName'
 import * as set from 'lib0/set'
-import type { ExprId, NodeMetadata } from 'shared/yjsModel.ts'
+import type { ExprId, NodeMetadata } from 'shared/yjsModel'
 import { computed, onMounted, ref, watch } from 'vue'
 import { type Usage } from './ComponentBrowser/input'
 
@@ -216,7 +216,7 @@ const graphBindingsHandler = graphBindings.handler({
 })
 
 const handleClick = useDoubleClick(
-  (e) => {
+  (e: MouseEvent) => {
     graphBindingsHandler(e)
   },
   () => {
diff --git a/app/gui2/src/components/GraphEditor/GraphEdge.vue b/app/gui2/src/components/GraphEditor/GraphEdge.vue
index a510d992294..3d4c72874d4 100644
--- a/app/gui2/src/components/GraphEditor/GraphEdge.vue
+++ b/app/gui2/src/components/GraphEditor/GraphEdge.vue
@@ -1,11 +1,11 @@
 <script setup lang="ts">
-import { injectGraphNavigator } from '@/providers/graphNavigator.ts'
-import { injectGraphSelection } from '@/providers/graphSelection.ts'
+import { injectGraphNavigator } from '@/providers/graphNavigator'
+import { injectGraphSelection } from '@/providers/graphSelection'
 import { useGraphStore, type Edge } from '@/stores/graph'
 import { assert } from '@/util/assert'
-import { Rect } from '@/util/rect'
+import { Rect } from '@/util/data/rect'
+import { Vec2 } from '@/util/data/vec2'
 import theme from '@/util/theme.json'
-import { Vec2 } from '@/util/vec2'
 import { clamp } from '@vueuse/core'
 import { computed, ref } from 'vue'
 
diff --git a/app/gui2/src/components/GraphEditor/GraphEdges.vue b/app/gui2/src/components/GraphEditor/GraphEdges.vue
index c2dda771718..3cbe3616206 100644
--- a/app/gui2/src/components/GraphEditor/GraphEdges.vue
+++ b/app/gui2/src/components/GraphEditor/GraphEdges.vue
@@ -1,11 +1,11 @@
 <script setup lang="ts">
 import GraphEdge from '@/components/GraphEditor/GraphEdge.vue'
-import type { GraphNavigator } from '@/providers/graphNavigator.ts'
-import { injectGraphSelection } from '@/providers/graphSelection.ts'
+import type { GraphNavigator } from '@/providers/graphNavigator'
+import { injectGraphSelection } from '@/providers/graphSelection'
 import { injectInteractionHandler, type Interaction } from '@/providers/interactionHandler'
 import { useGraphStore } from '@/stores/graph'
-import { Vec2 } from '@/util/vec2.ts'
-import type { ExprId } from 'shared/yjsModel.ts'
+import { Vec2 } from '@/util/data/vec2'
+import type { ExprId } from 'shared/yjsModel'
 
 const graph = useGraphStore()
 const selection = injectGraphSelection(true)
diff --git a/app/gui2/src/components/GraphEditor/GraphNode.vue b/app/gui2/src/components/GraphEditor/GraphNode.vue
index acc0e2b85f9..892b95154b5 100644
--- a/app/gui2/src/components/GraphEditor/GraphNode.vue
+++ b/app/gui2/src/components/GraphEditor/GraphNode.vue
@@ -5,17 +5,17 @@ import GraphNodeError from '@/components/GraphEditor/GraphNodeError.vue'
 import GraphVisualization from '@/components/GraphEditor/GraphVisualization.vue'
 import NodeWidgetTree from '@/components/GraphEditor/NodeWidgetTree.vue'
 import SvgIcon from '@/components/SvgIcon.vue'
+import { useApproach } from '@/composables/animation'
 import { useDoubleClick } from '@/composables/doubleClick'
+import { usePointer, useResizeObserver } from '@/composables/events'
 import { injectGraphNavigator } from '@/providers/graphNavigator'
 import { injectGraphSelection } from '@/providers/graphSelection'
 import { useGraphStore, type Node } from '@/stores/graph'
 import { useProjectStore } from '@/stores/project'
-import { useApproach } from '@/util/animation'
-import { usePointer, useResizeObserver } from '@/util/events'
+import type { Opt } from '@/util/data/opt'
+import { Rect } from '@/util/data/rect'
+import { Vec2 } from '@/util/data/vec2'
 import { displayedIconOf } from '@/util/getIconName'
-import type { Opt } from '@/util/opt'
-import { Rect } from '@/util/rect'
-import { Vec2 } from '@/util/vec2'
 import { setIfUndefined } from 'lib0/map'
 import type { ContentRange, ExprId, VisualizationIdentifier } from 'shared/yjsModel'
 import { computed, ref, watch, watchEffect } from 'vue'
@@ -214,20 +214,14 @@ function getRelatedSpanOffset(domNode: globalThis.Node, domOffset: number): numb
   return domOffset
 }
 
-const handlePortClick = useDoubleClick<[portId: ExprId]>(
-  (_e, portId) => emit('outputPortClick', portId),
-  (portId) => {
-    emit('outputPortDoubleClick', portId)
-  },
+const handlePortClick = useDoubleClick(
+  (portId: ExprId) => emit('outputPortClick', portId),
+  (portId: ExprId) => emit('outputPortDoubleClick', portId),
 ).handleClick
 
 const handleNodeClick = useDoubleClick(
-  (e) => {
-    nodeEditHandler(e)
-  },
-  () => {
-    emit('doubleClick')
-  },
+  (e: MouseEvent) => nodeEditHandler(e),
+  () => emit('doubleClick'),
 ).handleClick
 interface PortData {
   clipRange: [number, number]
@@ -339,7 +333,7 @@ function portGroupStyle(port: PortData) {
               class="outputPortHoverArea"
               @pointerenter="outputHovered = port.portId"
               @pointerleave="outputHovered = undefined"
-              @pointerdown.stop.prevent="handlePortClick($event, port.portId)"
+              @pointerdown.stop.prevent="handlePortClick(port.portId)"
             />
             <rect class="outputPort" />
           </g>
diff --git a/app/gui2/src/components/GraphEditor/GraphNodes.vue b/app/gui2/src/components/GraphEditor/GraphNodes.vue
index 4c8b98594d1..6ce21388691 100644
--- a/app/gui2/src/components/GraphEditor/GraphNodes.vue
+++ b/app/gui2/src/components/GraphEditor/GraphNodes.vue
@@ -7,7 +7,7 @@ import { injectGraphSelection } from '@/providers/graphSelection'
 import type { UploadingFile as File, FileName } from '@/stores/awareness'
 import { useGraphStore } from '@/stores/graph'
 import { useProjectStore } from '@/stores/project'
-import type { Vec2 } from '@/util/vec2'
+import type { Vec2 } from '@/util/data/vec2'
 import { stackItemsEqual } from 'shared/languageServerTypes'
 import type { ContentRange, ExprId } from 'shared/yjsModel'
 import { computed, toRaw } from 'vue'
diff --git a/app/gui2/src/components/GraphEditor/GraphVisualization.vue b/app/gui2/src/components/GraphEditor/GraphVisualization.vue
index 628db22a490..2e9e3daad50 100644
--- a/app/gui2/src/components/GraphEditor/GraphVisualization.vue
+++ b/app/gui2/src/components/GraphEditor/GraphVisualization.vue
@@ -11,13 +11,13 @@ import {
   type VisualizationDataSource,
 } from '@/stores/visualization'
 import type { Visualization } from '@/stores/visualization/runtimeTypes'
-import { toError } from '@/util/error'
+import { toError } from '@/util/data/error'
+import type { Opt } from '@/util/data/opt'
+import { Rect } from '@/util/data/rect'
+import type { Result } from '@/util/data/result'
+import type { URLString } from '@/util/data/urlString'
+import { Vec2 } from '@/util/data/vec2'
 import type { Icon } from '@/util/iconName'
-import type { Opt } from '@/util/opt'
-import { Rect } from '@/util/rect'
-import type { Result } from '@/util/result'
-import type { URLString } from '@/util/urlString'
-import { Vec2 } from '@/util/vec2'
 import { computedAsync } from '@vueuse/core'
 import type { VisualizationIdentifier } from 'shared/yjsModel'
 import {
diff --git a/app/gui2/src/components/GraphEditor/NodeWidget.vue b/app/gui2/src/components/GraphEditor/NodeWidget.vue
index a774bc15ec4..04b3ae64f3f 100644
--- a/app/gui2/src/components/GraphEditor/NodeWidget.vue
+++ b/app/gui2/src/components/GraphEditor/NodeWidget.vue
@@ -8,7 +8,7 @@ import {
   usageKeyForInput,
 } from '@/providers/widgetUsageInfo'
 import { Ast } from '@/util/ast'
-import type { Opt } from '@/util/opt'
+import type { Opt } from '@/util/data/opt'
 import { computed, proxyRefs } from 'vue'
 
 const props = defineProps<{
diff --git a/app/gui2/src/components/GraphEditor/NodeWidgetTree.vue b/app/gui2/src/components/GraphEditor/NodeWidgetTree.vue
index 148d33cd99c..3679a56b1c8 100644
--- a/app/gui2/src/components/GraphEditor/NodeWidgetTree.vue
+++ b/app/gui2/src/components/GraphEditor/NodeWidgetTree.vue
@@ -1,11 +1,11 @@
 <script setup lang="ts">
+import NodeWidget from '@/components/GraphEditor/NodeWidget.vue'
+import { useTransitioning } from '@/composables/animation'
 import { ForcePort } from '@/providers/portInfo'
 import { provideWidgetTree } from '@/providers/widgetTree'
 import { useGraphStore } from '@/stores/graph'
-import { useTransitioning } from '@/util/animation'
 import { Ast } from '@/util/ast'
 import { computed, toRef } from 'vue'
-import NodeWidget from './NodeWidget.vue'
 
 const props = defineProps<{ ast: Ast.Ast }>()
 const graph = useGraphStore()
diff --git a/app/gui2/src/components/GraphEditor/__tests__/dragging.test.ts b/app/gui2/src/components/GraphEditor/__tests__/dragging.test.ts
index 2ea662446e1..04fc1bd92e2 100644
--- a/app/gui2/src/components/GraphEditor/__tests__/dragging.test.ts
+++ b/app/gui2/src/components/GraphEditor/__tests__/dragging.test.ts
@@ -1,6 +1,6 @@
 import { SnapGrid } from '@/components/GraphEditor/dragging'
-import { Rect } from '@/util/rect'
-import { Vec2 } from '@/util/vec2'
+import { Rect } from '@/util/data/rect'
+import { Vec2 } from '@/util/data/vec2'
 import { expect, test } from 'vitest'
 import { computed } from 'vue'
 
diff --git a/app/gui2/src/components/GraphEditor/dragging.ts b/app/gui2/src/components/GraphEditor/dragging.ts
index 0ad8b5ae7b7..3851bd058aa 100644
--- a/app/gui2/src/components/GraphEditor/dragging.ts
+++ b/app/gui2/src/components/GraphEditor/dragging.ts
@@ -1,11 +1,11 @@
+import { useApproach } from '@/composables/animation'
 import { injectGraphSelection } from '@/providers/graphSelection'
 import { useGraphStore } from '@/stores/graph'
-import { useApproach } from '@/util/animation'
-import { partitionPoint } from '@/util/array'
-import type { Opt } from '@/util/opt'
-import { Rect } from '@/util/rect'
+import { partitionPoint } from '@/util/data/array'
+import type { Opt } from '@/util/data/opt'
+import { Rect } from '@/util/data/rect'
+import { Vec2 } from '@/util/data/vec2'
 import theme from '@/util/theme.json'
-import { Vec2 } from '@/util/vec2'
 import { iteratorFilter } from 'lib0/iterator'
 import type { ExprId } from 'shared/yjsModel'
 import { computed, markRaw, ref, watchEffect, type ComputedRef, type WatchStopHandle } from 'vue'
diff --git a/app/gui2/src/components/GraphEditor/upload.ts b/app/gui2/src/components/GraphEditor/upload.ts
index 4432c7e0053..86bf41551f9 100644
--- a/app/gui2/src/components/GraphEditor/upload.ts
+++ b/app/gui2/src/components/GraphEditor/upload.ts
@@ -1,6 +1,6 @@
 import { Awareness } from '@/stores/awareness'
 import * as astText from '@/util/ast/text'
-import { Vec2 } from '@/util/vec2'
+import { Vec2 } from '@/util/data/vec2'
 import { Keccak, sha3_224 as SHA3 } from '@noble/hashes/sha3'
 import type { Hash } from '@noble/hashes/utils'
 import { bytesToHex } from '@noble/hashes/utils'
diff --git a/app/gui2/src/components/GraphEditor/widgets/WidgetFunction.vue b/app/gui2/src/components/GraphEditor/widgets/WidgetFunction.vue
index 69f9bfc68a5..69ffefce909 100644
--- a/app/gui2/src/components/GraphEditor/widgets/WidgetFunction.vue
+++ b/app/gui2/src/components/GraphEditor/widgets/WidgetFunction.vue
@@ -7,7 +7,7 @@ import { useGraphStore } from '@/stores/graph'
 import { useProjectStore, type NodeVisualizationConfiguration } from '@/stores/project'
 import { Ast } from '@/util/ast'
 import { ArgumentApplication } from '@/util/callTree'
-import type { Opt } from '@/util/opt'
+import type { Opt } from '@/util/data/opt'
 import type { ExprId } from 'shared/yjsModel'
 import { computed, proxyRefs } from 'vue'
 
diff --git a/app/gui2/src/components/GraphEditor/widgets/WidgetPort.vue b/app/gui2/src/components/GraphEditor/widgets/WidgetPort.vue
index 917810e04c2..4f7097986e4 100644
--- a/app/gui2/src/components/GraphEditor/widgets/WidgetPort.vue
+++ b/app/gui2/src/components/GraphEditor/widgets/WidgetPort.vue
@@ -1,5 +1,7 @@
 <script setup lang="ts">
 import NodeWidget from '@/components/GraphEditor/NodeWidget.vue'
+import { useRaf } from '@/composables/animation'
+import { useResizeObserver } from '@/composables/events'
 import { injectGraphNavigator } from '@/providers/graphNavigator'
 import { injectGraphSelection } from '@/providers/graphSelection'
 import { ForcePort, injectPortInfo, providePortInfo } from '@/providers/portInfo'
@@ -7,11 +9,9 @@ import type { WidgetInput } from '@/providers/widgetRegistry'
 import { Score, defineWidget, widgetProps } from '@/providers/widgetRegistry'
 import { injectWidgetTree } from '@/providers/widgetTree'
 import { useGraphStore } from '@/stores/graph'
-import { useRaf } from '@/util/animation'
 import { Ast } from '@/util/ast'
 import { ArgumentAst, ArgumentPlaceholder } from '@/util/callTree'
-import { useResizeObserver } from '@/util/events'
-import { Rect } from '@/util/rect'
+import { Rect } from '@/util/data/rect'
 import { uuidv4 } from 'lib0/random'
 import type { ExprId } from 'shared/yjsModel'
 import {
diff --git a/app/gui2/src/components/GraphEditor/widgets/WidgetSelection.vue b/app/gui2/src/components/GraphEditor/widgets/WidgetSelection.vue
index 7670d707e02..461f8f16a1b 100644
--- a/app/gui2/src/components/GraphEditor/widgets/WidgetSelection.vue
+++ b/app/gui2/src/components/GraphEditor/widgets/WidgetSelection.vue
@@ -1,9 +1,10 @@
 <script setup lang="ts">
 import NodeWidget from '@/components/GraphEditor/NodeWidget.vue'
 import DropdownWidget from '@/components/widgets/DropdownWidget.vue'
-import { widgetProps } from '@/providers/widgetRegistry'
+import { Score, defineWidget, widgetProps } from '@/providers/widgetRegistry'
 import { useGraphStore } from '@/stores/graph'
-import { qnJoin, qnSegments, tryQualifiedName } from '@/util/qualifiedName.ts'
+import { ArgumentAst, ArgumentPlaceholder } from '@/util/callTree'
+import { qnJoin, qnSegments, tryQualifiedName } from '@/util/qualifiedName'
 import { computed, nextTick, onMounted, ref, watch } from 'vue'
 
 const props = defineProps(widgetProps(widgetDefinition))
@@ -89,9 +90,6 @@ watch(selectedIndex, (_index) => {
 </script>
 
 <script lang="ts">
-import { defineWidget, Score } from '@/providers/widgetRegistry.ts'
-import { ArgumentAst, ArgumentPlaceholder } from '@/util/callTree.ts'
-
 export const widgetDefinition = defineWidget([ArgumentPlaceholder, ArgumentAst], {
   priority: 999,
   score: (props) => {
diff --git a/app/gui2/src/components/GraphMouse.vue b/app/gui2/src/components/GraphMouse.vue
index 84af6e98971..30aa073a755 100644
--- a/app/gui2/src/components/GraphMouse.vue
+++ b/app/gui2/src/components/GraphMouse.vue
@@ -1,9 +1,9 @@
 <script setup lang="ts">
+import SelectionBrush from '@/components/SelectionBrush.vue'
+import { useEvent } from '@/composables/events'
 import { injectGraphNavigator } from '@/providers/graphNavigator'
 import { injectGraphSelection } from '@/providers/graphSelection'
-import { useEvent } from '@/util/events'
 import { computed, ref } from 'vue'
-import SelectionBrush from './SelectionBrush.vue'
 
 const navigator = injectGraphNavigator(true)
 const nodeSelection = injectGraphSelection(true)
diff --git a/app/gui2/src/components/SelectionBrush.vue b/app/gui2/src/components/SelectionBrush.vue
index ba5409809dd..1dd741a5057 100644
--- a/app/gui2/src/components/SelectionBrush.vue
+++ b/app/gui2/src/components/SelectionBrush.vue
@@ -1,6 +1,6 @@
 <script setup lang="ts">
-import { useApproach } from '@/util/animation'
-import type { Vec2 } from '@/util/vec2'
+import { useApproach } from '@/composables/animation'
+import type { Vec2 } from '@/util/data/vec2'
 import { computed, watch, type Ref } from 'vue'
 
 const props = defineProps<{
diff --git a/app/gui2/src/components/SvgIcon.vue b/app/gui2/src/components/SvgIcon.vue
index 439dca4b2b8..9ec99ae5e86 100644
--- a/app/gui2/src/components/SvgIcon.vue
+++ b/app/gui2/src/components/SvgIcon.vue
@@ -5,8 +5,8 @@
  * It displays one group defined in `@/assets/icons.svg` file, specified by `variant` property.
  */
 import icons from '@/assets/icons.svg'
+import type { URLString } from '@/util/data/urlString'
 import type { Icon } from '@/util/iconName'
-import type { URLString } from '@/util/urlString'
 
 const props = defineProps<{ name: Icon | URLString; width?: number; height?: number }>()
 </script>
diff --git a/app/gui2/src/components/TopBar.vue b/app/gui2/src/components/TopBar.vue
index 5eeaa1fee53..87f5efa0bfb 100644
--- a/app/gui2/src/components/TopBar.vue
+++ b/app/gui2/src/components/TopBar.vue
@@ -53,4 +53,3 @@ const barStyle = computed(() => {
   left: 9px;
 }
 </style>
-@/providers/guiConfig
diff --git a/app/gui2/src/components/VisualizationContainer.vue b/app/gui2/src/components/VisualizationContainer.vue
index 53a2fa5bf8f..084b7b83b4a 100644
--- a/app/gui2/src/components/VisualizationContainer.vue
+++ b/app/gui2/src/components/VisualizationContainer.vue
@@ -1,8 +1,8 @@
 <script setup lang="ts">
 import SvgIcon from '@/components/SvgIcon.vue'
 import VisualizationSelector from '@/components/VisualizationSelector.vue'
+import { PointerButtonMask, isTriggeredByKeyboard, usePointer } from '@/composables/events'
 import { useVisualizationConfig } from '@/providers/visualizationConfig'
-import { PointerButtonMask, isTriggeredByKeyboard, usePointer } from '@/util/events'
 import { onMounted, ref, watchEffect } from 'vue'
 
 const props = defineProps<{
diff --git a/app/gui2/src/components/VisualizationSelector.vue b/app/gui2/src/components/VisualizationSelector.vue
index 3ec3c1d636c..c3fcfcbeb0a 100644
--- a/app/gui2/src/components/VisualizationSelector.vue
+++ b/app/gui2/src/components/VisualizationSelector.vue
@@ -1,8 +1,8 @@
 <script setup lang="ts">
 import SvgIcon from '@/components/SvgIcon.vue'
 import { useAutoBlur } from '@/util/autoBlur'
+import type { URLString } from '@/util/data/urlString'
 import type { Icon } from '@/util/iconName'
-import type { URLString } from '@/util/urlString'
 import { computedAsync } from '@vueuse/core'
 import { visIdentifierEquals, type VisualizationIdentifier } from 'shared/yjsModel'
 import { onMounted, ref } from 'vue'
diff --git a/app/gui2/src/components/visualizations/HistogramVisualization.vue b/app/gui2/src/components/visualizations/HistogramVisualization.vue
index e8dcf5f4845..62a7ed5f215 100644
--- a/app/gui2/src/components/visualizations/HistogramVisualization.vue
+++ b/app/gui2/src/components/visualizations/HistogramVisualization.vue
@@ -1,6 +1,6 @@
 <script lang="ts">
 import SvgIcon from '@/components/SvgIcon.vue'
-import { useEvent } from '@/util/events'
+import { useEvent } from '@/composables/events'
 import { getTextWidth } from '@/util/measurement'
 import { defineKeybinds } from '@/util/shortcuts'
 import { VisualizationContainer, useVisualizationConfig } from '@/util/visualizationBuiltins'
diff --git a/app/gui2/src/components/visualizations/ScatterplotVisualization.vue b/app/gui2/src/components/visualizations/ScatterplotVisualization.vue
index 580b8985124..c646b216a78 100644
--- a/app/gui2/src/components/visualizations/ScatterplotVisualization.vue
+++ b/app/gui2/src/components/visualizations/ScatterplotVisualization.vue
@@ -1,7 +1,7 @@
 <script lang="ts">
 import SvgIcon from '@/components/SvgIcon.vue'
+import { useEvent } from '@/composables/events'
 import { useVisualizationConfig } from '@/providers/visualizationConfig'
-import { useEvent } from '@/util/events'
 import { getTextWidth } from '@/util/measurement'
 import { VisualizationContainer, defineKeybinds } from '@/util/visualizationBuiltins'
 import { computed, ref, watch, watchEffect, watchPostEffect } from 'vue'
diff --git a/app/gui2/src/components/widgets/ListWidget.vue b/app/gui2/src/components/widgets/ListWidget.vue
index 1904c49643a..c8d9c30957c 100644
--- a/app/gui2/src/components/widgets/ListWidget.vue
+++ b/app/gui2/src/components/widgets/ListWidget.vue
@@ -1,10 +1,10 @@
 <script lang="ts">
 import SvgIcon from '@/components/SvgIcon.vue'
+import { useRaf } from '@/composables/animation'
+import { useEvent } from '@/composables/events'
 import { useAppClass } from '@/providers/appClass'
-import { useRaf } from '@/util/animation'
-import { useEvent } from '@/util/events'
-import { Range } from '@/util/range'
-import { Vec2 } from '@/util/vec2'
+import { Range } from '@/util/data/range'
+import { Vec2 } from '@/util/data/vec2'
 import { uuidv4 } from 'lib0/random'
 import { nextTick } from 'process'
 import { computed, ref, shallowReactive, watchEffect, watchPostEffect } from 'vue'
diff --git a/app/gui2/src/components/widgets/SliderWidget.vue b/app/gui2/src/components/widgets/SliderWidget.vue
index 2ed5484b5d9..9000a6e66b2 100644
--- a/app/gui2/src/components/widgets/SliderWidget.vue
+++ b/app/gui2/src/components/widgets/SliderWidget.vue
@@ -1,5 +1,5 @@
 <script setup lang="ts">
-import { PointerButtonMask, usePointer, useResizeObserver } from '@/util/events'
+import { PointerButtonMask, usePointer, useResizeObserver } from '@/composables/events'
 import { getTextWidth } from '@/util/measurement'
 import { computed, ref, type StyleValue } from 'vue'
 
diff --git a/app/gui2/src/composables/README.md b/app/gui2/src/composables/README.md
new file mode 100644
index 00000000000..74aa1e38247
--- /dev/null
+++ b/app/gui2/src/composables/README.md
@@ -0,0 +1,3 @@
+# Vue composables
+
+This directory contains various Vue composables, mostly used to interact with the DOM.
diff --git a/app/gui2/src/util/__tests__/navigator.test.ts b/app/gui2/src/composables/__tests__/navigator.test.ts
similarity index 94%
rename from app/gui2/src/util/__tests__/navigator.test.ts
rename to app/gui2/src/composables/__tests__/navigator.test.ts
index 2dd71f3a53f..1a58a865797 100644
--- a/app/gui2/src/util/__tests__/navigator.test.ts
+++ b/app/gui2/src/composables/__tests__/navigator.test.ts
@@ -1,6 +1,6 @@
-import { useNavigator } from '@/util/navigator'
-import { Rect } from '@/util/rect'
-import { Vec2 } from '@/util/vec2'
+import { useNavigator } from '@/composables/navigator'
+import { Rect } from '@/util/data/rect'
+import { Vec2 } from '@/util/data/vec2'
 import { afterEach, beforeEach, describe, expect, test, vi } from 'vitest'
 import { effectScope, ref } from 'vue'
 
diff --git a/app/gui2/src/util/animation.ts b/app/gui2/src/composables/animation.ts
similarity index 97%
rename from app/gui2/src/util/animation.ts
rename to app/gui2/src/composables/animation.ts
index 18c6e7f1786..649e35a2836 100644
--- a/app/gui2/src/util/animation.ts
+++ b/app/gui2/src/composables/animation.ts
@@ -1,3 +1,5 @@
+/** @file Vue composables for running a callback on every frame, and smooth interpolation. */
+
 import { watchSourceToRef } from '@/util/reactivity'
 import { onScopeDispose, proxyRefs, ref, watch, type WatchSource } from 'vue'
 
diff --git a/app/gui2/src/composables/doubleClick.ts b/app/gui2/src/composables/doubleClick.ts
index 82416396512..6d3aa225c68 100644
--- a/app/gui2/src/composables/doubleClick.ts
+++ b/app/gui2/src/composables/doubleClick.ts
@@ -1,15 +1,21 @@
+/** @file A Vue composable that calls one of two given callbacks, depending on whether a click is
+ * a single click or a double click. */
+
+/** Calls {@link onClick} if a click is a single click, or {@link onDoubleClick} if a click is
+ * a double click. For this function, a double click is defined as a second click that occurs within
+ * 200ms of the first click. The click count is reset to 0 upon double click, or after 200ms. */
 export function useDoubleClick<Args extends any[]>(
-  onClick: (e: MouseEvent, ...args: Args) => void,
+  onClick: (...args: Args) => void,
   onDoubleClick: (...args: Args) => void,
 ) {
   const timeBetweenClicks = 200
   let clickCount = 0
   let singleClickTimer: ReturnType<typeof setTimeout>
 
-  const handleClick = (e: MouseEvent, ...args: Args) => {
+  const handleClick = (...args: Args) => {
     clickCount++
     if (clickCount === 1) {
-      onClick(e, ...args)
+      onClick(...args)
       singleClickTimer = setTimeout(() => {
         clickCount = 0
       }, timeBetweenClicks)
diff --git a/app/gui2/src/util/events.ts b/app/gui2/src/composables/events.ts
similarity index 98%
rename from app/gui2/src/util/events.ts
rename to app/gui2/src/composables/events.ts
index 042428d0d03..c83626995dd 100644
--- a/app/gui2/src/util/events.ts
+++ b/app/gui2/src/composables/events.ts
@@ -1,5 +1,7 @@
-import type { Opt } from '@/util/opt'
-import { Vec2 } from '@/util/vec2'
+/** @file Vue composables for listening to DOM events. */
+
+import type { Opt } from '@/util/data/opt'
+import { Vec2 } from '@/util/data/vec2'
 import {
   computed,
   onScopeDispose,
diff --git a/app/gui2/src/util/navigator.ts b/app/gui2/src/composables/navigator.ts
similarity index 96%
rename from app/gui2/src/util/navigator.ts
rename to app/gui2/src/composables/navigator.ts
index dc886b628ff..950a2cf9f98 100644
--- a/app/gui2/src/util/navigator.ts
+++ b/app/gui2/src/composables/navigator.ts
@@ -1,7 +1,9 @@
-import { useApproach } from '@/util/animation'
-import { PointerButtonMask, useEvent, usePointer, useResizeObserver } from '@/util/events'
-import { Rect } from '@/util/rect'
-import { Vec2 } from '@/util/vec2'
+/** @file A Vue composable for panning and zooming a DOM element. */
+
+import { useApproach } from '@/composables/animation'
+import { PointerButtonMask, useEvent, usePointer, useResizeObserver } from '@/composables/events'
+import { Rect } from '@/util/data/rect'
+import { Vec2 } from '@/util/data/vec2'
 import { computed, proxyRefs, ref, type Ref } from 'vue'
 
 function elemRect(target: Element | undefined): Rect {
diff --git a/app/gui2/src/util/selection.ts b/app/gui2/src/composables/selection.ts
similarity index 93%
rename from app/gui2/src/util/selection.ts
rename to app/gui2/src/composables/selection.ts
index b9fcc33dc7d..2749342ca0b 100644
--- a/app/gui2/src/util/selection.ts
+++ b/app/gui2/src/composables/selection.ts
@@ -1,10 +1,12 @@
+/** @file A Vue composable for keeping track of selected DOM elements. */
+
 import { selectionMouseBindings } from '@/bindings'
-import { usePointer } from '@/util/events'
-import type { NavigatorComposable } from '@/util/navigator'
-import type { Rect } from '@/util/rect'
-import type { Vec2 } from '@/util/vec2'
+import { usePointer } from '@/composables/events'
+import type { NavigatorComposable } from '@/composables/navigator'
+import type { Rect } from '@/util/data/rect'
+import type { Vec2 } from '@/util/data/vec2'
+import { type ExprId } from 'shared/yjsModel'
 import { computed, proxyRefs, reactive, ref, shallowRef } from 'vue'
-import { type ExprId } from '../../shared/yjsModel.ts'
 
 export type SelectionComposable<T> = ReturnType<typeof useSelection<T>>
 export function useSelection<T>(
diff --git a/app/gui2/src/providers/README.md b/app/gui2/src/providers/README.md
new file mode 100644
index 00000000000..aa3a103cc48
--- /dev/null
+++ b/app/gui2/src/providers/README.md
@@ -0,0 +1,11 @@
+# Providers
+
+This folder contains [Vue providers](provider).
+
+All providers MUST be at the top level - so either `./providers/myProvider.ts`,
+or `./providers/myProvider/index.ts`.
+
+Each provider MAY have dependencies specific to itself, which MUST NOT be at the
+top level - so `./providers/myProvider/myDependency.ts`.
+
+[provider]: https://vuejs.org/guide/components/provide-inject
diff --git a/app/gui2/src/providers/__tests__/widgetRegistry.test.ts b/app/gui2/src/providers/__tests__/widgetRegistry.test.ts
index a0929c642e7..1ece5c99907 100644
--- a/app/gui2/src/providers/__tests__/widgetRegistry.test.ts
+++ b/app/gui2/src/providers/__tests__/widgetRegistry.test.ts
@@ -1,8 +1,3 @@
-import { GraphDb } from '@/stores/graph/graphDatabase'
-import { Ast } from '@/util/ast'
-import { ApplicationKind, ArgumentPlaceholder } from '@/util/callTree'
-import { describe, expect, test } from 'vitest'
-import { defineComponent } from 'vue'
 import {
   Score,
   WidgetRegistry,
@@ -10,8 +5,13 @@ import {
   type WidgetDefinition,
   type WidgetInput,
   type WidgetModule,
-} from '../widgetRegistry'
-import { DisplayMode, widgetConfigurationSchema } from '../widgetRegistry/configuration'
+} from '@/providers/widgetRegistry'
+import { DisplayMode, widgetConfigurationSchema } from '@/providers/widgetRegistry/configuration'
+import { GraphDb } from '@/stores/graph/graphDatabase'
+import { Ast } from '@/util/ast'
+import { ApplicationKind, ArgumentPlaceholder } from '@/util/callTree'
+import { describe, expect, test } from 'vitest'
+import { defineComponent } from 'vue'
 
 describe('WidgetRegistry', () => {
   function makeMockWidget<T extends WidgetInput>(
diff --git a/app/gui2/src/providers/appClass.ts b/app/gui2/src/providers/appClass.ts
index 0a0d2b26205..d0dcef6b01f 100644
--- a/app/gui2/src/providers/appClass.ts
+++ b/app/gui2/src/providers/appClass.ts
@@ -1,6 +1,6 @@
-import type { Opt } from '@/util/opt'
+import { createContextStore } from '@/providers'
+import type { Opt } from '@/util/data/opt'
 import { reactive, watch, type WatchSource } from 'vue'
-import { createContextStore } from '.'
 
 export { provideFn as provideAppClassSet }
 const { provideFn, injectFn: injectAppClassSet } = createContextStore('Port info', () => {
diff --git a/app/gui2/src/providers/functionInfo.ts b/app/gui2/src/providers/functionInfo.ts
index b00f16e437b..4dd9ac7e883 100644
--- a/app/gui2/src/providers/functionInfo.ts
+++ b/app/gui2/src/providers/functionInfo.ts
@@ -1,6 +1,6 @@
+import { createContextStore } from '@/providers'
 import { identity } from '@vueuse/core'
 import type { ExprId } from 'shared/yjsModel'
-import { createContextStore } from '.'
 
 interface FunctionInfo {
   callId: ExprId | undefined
diff --git a/app/gui2/src/providers/graphNavigator.ts b/app/gui2/src/providers/graphNavigator.ts
index d9a5e7c2d42..af27f1880fb 100644
--- a/app/gui2/src/providers/graphNavigator.ts
+++ b/app/gui2/src/providers/graphNavigator.ts
@@ -1,5 +1,5 @@
-import { useNavigator } from '@/util/navigator'
-import { createContextStore } from '.'
+import { useNavigator } from '@/composables/navigator'
+import { createContextStore } from '@/providers'
 
 export type GraphNavigator = ReturnType<typeof injectFn>
 export { injectFn as injectGraphNavigator, provideFn as provideGraphNavigator }
diff --git a/app/gui2/src/providers/graphSelection.ts b/app/gui2/src/providers/graphSelection.ts
index 7427b81793d..12f711a7468 100644
--- a/app/gui2/src/providers/graphSelection.ts
+++ b/app/gui2/src/providers/graphSelection.ts
@@ -1,8 +1,8 @@
-import type { NavigatorComposable } from '@/util/navigator'
-import type { Rect } from '@/util/rect'
-import { useSelection } from '@/util/selection'
+import type { NavigatorComposable } from '@/composables/navigator'
+import { useSelection } from '@/composables/selection'
+import { createContextStore } from '@/providers'
+import type { Rect } from '@/util/data/rect'
 import type { ExprId } from 'shared/yjsModel'
-import { createContextStore } from '.'
 
 const SELECTION_BRUSH_MARGIN_PX = 6
 
diff --git a/app/gui2/src/providers/guiConfig.ts b/app/gui2/src/providers/guiConfig.ts
index 5ecf2765bb8..809ad74ce2c 100644
--- a/app/gui2/src/providers/guiConfig.ts
+++ b/app/gui2/src/providers/guiConfig.ts
@@ -1,6 +1,6 @@
+import { createContextStore } from '@/providers'
 import { identity } from '@vueuse/core'
 import { type Ref } from 'vue'
-import { createContextStore } from '.'
 
 export interface GuiConfig {
   engine?: {
diff --git a/app/gui2/src/providers/interactionHandler.ts b/app/gui2/src/providers/interactionHandler.ts
index bc09d8dc49a..c28ed6c26b0 100644
--- a/app/gui2/src/providers/interactionHandler.ts
+++ b/app/gui2/src/providers/interactionHandler.ts
@@ -1,6 +1,6 @@
-import type { GraphNavigator } from '@/providers/graphNavigator.ts'
+import { createContextStore } from '@/providers'
+import type { GraphNavigator } from '@/providers/graphNavigator'
 import { watch, type WatchSource } from 'vue'
-import { createContextStore } from '.'
 
 export { injectFn as injectInteractionHandler, provideFn as provideInteractionHandler }
 const { provideFn, injectFn } = createContextStore(
diff --git a/app/gui2/src/providers/portInfo.ts b/app/gui2/src/providers/portInfo.ts
index 5f72d85a3eb..7926d4bc2ea 100644
--- a/app/gui2/src/providers/portInfo.ts
+++ b/app/gui2/src/providers/portInfo.ts
@@ -1,7 +1,7 @@
+import { createContextStore } from '@/providers'
+import { GetUsageKey } from '@/providers/widgetUsageInfo'
 import { Ast } from '@/util/ast'
 import { identity } from '@vueuse/core'
-import { createContextStore } from '.'
-import { GetUsageKey } from './widgetUsageInfo'
 
 interface PortInfo {
   portId: string
diff --git a/app/gui2/src/providers/visualizationConfig.ts b/app/gui2/src/providers/visualizationConfig.ts
index 7848b30b095..ad77c05f899 100644
--- a/app/gui2/src/providers/visualizationConfig.ts
+++ b/app/gui2/src/providers/visualizationConfig.ts
@@ -1,7 +1,7 @@
 import { createContextStore } from '@/providers'
+import type { URLString } from '@/util/data/urlString'
+import { Vec2 } from '@/util/data/vec2'
 import type { Icon } from '@/util/iconName'
-import type { URLString } from '@/util/urlString'
-import { Vec2 } from '@/util/vec2'
 import type { VisualizationIdentifier } from 'shared/yjsModel'
 import { reactive } from 'vue'
 
diff --git a/app/gui2/src/providers/widgetRegistry.ts b/app/gui2/src/providers/widgetRegistry.ts
index f5ba13355f1..1ae78c3a451 100644
--- a/app/gui2/src/providers/widgetRegistry.ts
+++ b/app/gui2/src/providers/widgetRegistry.ts
@@ -1,7 +1,7 @@
+import { createContextStore } from '@/providers'
 import { type WidgetConfiguration } from '@/providers/widgetRegistry/configuration'
 import type { GraphDb } from '@/stores/graph/graphDatabase'
 import { computed, shallowReactive, type Component, type PropType } from 'vue'
-import { createContextStore } from '.'
 
 export type WidgetComponent<T extends WidgetInput> = Component<WidgetProps<T>>
 
diff --git a/app/gui2/src/providers/widgetTree.ts b/app/gui2/src/providers/widgetTree.ts
index e6c06939a15..e47950a90c1 100644
--- a/app/gui2/src/providers/widgetTree.ts
+++ b/app/gui2/src/providers/widgetTree.ts
@@ -1,6 +1,6 @@
+import { createContextStore } from '@/providers'
 import { Ast } from '@/util/ast'
 import { computed, proxyRefs, type Ref } from 'vue'
-import { createContextStore } from '.'
 
 export { injectFn as injectWidgetTree, provideFn as provideWidgetTree }
 const { provideFn, injectFn } = createContextStore(
diff --git a/app/gui2/src/providers/widgetUsageInfo.ts b/app/gui2/src/providers/widgetUsageInfo.ts
index dc4fc10d62f..c9288d394b3 100644
--- a/app/gui2/src/providers/widgetUsageInfo.ts
+++ b/app/gui2/src/providers/widgetUsageInfo.ts
@@ -1,6 +1,6 @@
+import { createContextStore } from '@/providers'
+import type { WidgetComponent, WidgetInput } from '@/providers/widgetRegistry'
 import { identity } from '@vueuse/core'
-import { createContextStore } from '.'
-import type { WidgetComponent, WidgetInput } from './widgetRegistry'
 
 export { injectFn as injectWidgetUsageInfo, provideFn as provideWidgetUsageInfo }
 const { provideFn, injectFn } = createContextStore('Widget usage info', identity<WidgetUsageInfo>)
diff --git a/app/gui2/src/stores/README.md b/app/gui2/src/stores/README.md
new file mode 100644
index 00000000000..49e21ce7f62
--- /dev/null
+++ b/app/gui2/src/stores/README.md
@@ -0,0 +1,11 @@
+# Stores
+
+This folder contains [Pinia] stores.
+
+All stores MUST be at the top level - so either `./stores/myStore.ts`, or
+`./stores/myStore/index.ts`.
+
+Each store MAY have dependencies specific to itself, which MUST NOT be at the
+top level - so `./stores/myStore/myDependency.ts`.
+
+[Pinia]: https://pinia.vuejs.org/
diff --git a/app/gui2/src/stores/awareness.ts b/app/gui2/src/stores/awareness.ts
index c97e03a891e..6fb4c401172 100644
--- a/app/gui2/src/stores/awareness.ts
+++ b/app/gui2/src/stores/awareness.ts
@@ -1,4 +1,4 @@
-import { Vec2 } from '@/util/vec2'
+import { Vec2 } from '@/util/data/vec2'
 import type { StackItem } from 'shared/languageServerTypes'
 import { reactive } from 'vue'
 import { Awareness as YjsAwareness } from 'y-protocols/awareness'
diff --git a/app/gui2/src/stores/graph/__tests__/graphDatabase.test.ts b/app/gui2/src/stores/graph/__tests__/graphDatabase.test.ts
index be6531115a5..31223835e5d 100644
--- a/app/gui2/src/stores/graph/__tests__/graphDatabase.test.ts
+++ b/app/gui2/src/stores/graph/__tests__/graphDatabase.test.ts
@@ -1,8 +1,8 @@
+import { GraphDb } from '@/stores/graph/graphDatabase'
 import { Ast } from '@/util/ast'
 import assert from 'assert'
 import { IdMap, type ExprId } from 'shared/yjsModel'
 import { expect, test } from 'vitest'
-import { GraphDb } from '../graphDatabase'
 
 test('Reading graph from definition', () => {
   const code = 'function a =\n    node1 = a + 4\n    node2 = node1 + 4'
diff --git a/app/gui2/src/stores/graph/graphDatabase.ts b/app/gui2/src/stores/graph/graphDatabase.ts
index 44fa5da344e..e8cf1b6f734 100644
--- a/app/gui2/src/stores/graph/graphDatabase.ts
+++ b/app/gui2/src/stores/graph/graphDatabase.ts
@@ -1,14 +1,14 @@
 import { ComputedValueRegistry, type ExpressionInfo } from '@/stores/project/computedValueRegistry'
 import { SuggestionDb, groupColorStyle, type Group } from '@/stores/suggestionDatabase'
 import type { SuggestionEntry } from '@/stores/suggestionDatabase/entry'
-import { arrayEquals, byteArraysEqual, tryGetIndex } from '@/util/array'
 import { Ast, RawAst, RawAstExtended } from '@/util/ast'
 import { AliasAnalyzer } from '@/util/ast/aliasAnalysis'
 import { colorFromString } from '@/util/colors'
 import { MappedKeyMap, MappedSet } from '@/util/containers'
+import { arrayEquals, byteArraysEqual, tryGetIndex } from '@/util/data/array'
+import type { Opt } from '@/util/data/opt'
+import { Vec2 } from '@/util/data/vec2'
 import { ReactiveDb, ReactiveIndex, ReactiveMapping } from '@/util/database/reactiveDb'
-import type { Opt } from '@/util/opt'
-import { Vec2 } from '@/util/vec2'
 import * as set from 'lib0/set'
 import { methodPointerEquals, type MethodCall } from 'shared/languageServerTypes'
 import {
diff --git a/app/gui2/src/stores/graph/imports.ts b/app/gui2/src/stores/graph/imports.ts
index 593c156dd41..ef09b89793d 100644
--- a/app/gui2/src/stores/graph/imports.ts
+++ b/app/gui2/src/stores/graph/imports.ts
@@ -9,6 +9,7 @@ import {
   type SuggestionEntry,
 } from '@/stores/suggestionDatabase/entry'
 import { Ast } from '@/util/ast'
+import { unwrap } from '@/util/data/result'
 import {
   identifierUnchecked,
   normalizeQualifiedName,
@@ -19,7 +20,6 @@ import {
   type Identifier,
   type QualifiedName,
 } from '@/util/qualifiedName'
-import { unwrap } from '@/util/result'
 
 // ========================
 // === Imports analysis ===
diff --git a/app/gui2/src/stores/graph/index.ts b/app/gui2/src/stores/graph/index.ts
index d899828ca48..e620eeda7f6 100644
--- a/app/gui2/src/stores/graph/index.ts
+++ b/app/gui2/src/stores/graph/index.ts
@@ -11,9 +11,9 @@ import { useProjectStore } from '@/stores/project'
 import { useSuggestionDbStore } from '@/stores/suggestionDatabase'
 import { Ast } from '@/util/ast'
 import { useObserveYjs } from '@/util/crdt'
-import type { Opt } from '@/util/opt'
-import { Rect } from '@/util/rect'
-import { Vec2 } from '@/util/vec2'
+import type { Opt } from '@/util/data/opt'
+import { Rect } from '@/util/data/rect'
+import { Vec2 } from '@/util/data/vec2'
 import { defineStore } from 'pinia'
 import type { StackItem } from 'shared/languageServerTypes'
 import {
diff --git a/app/gui2/src/stores/project/index.ts b/app/gui2/src/stores/project/index.ts
index 76add39e572..3866ac93abe 100644
--- a/app/gui2/src/stores/project/index.ts
+++ b/app/gui2/src/stores/project/index.ts
@@ -3,6 +3,9 @@ import { Awareness } from '@/stores/awareness'
 import { ComputedValueRegistry } from '@/stores/project/computedValueRegistry'
 import { VisualizationDataRegistry } from '@/stores/project/visualizationDataRegistry'
 import { attachProvider, useObserveYjs } from '@/util/crdt'
+import { nextEvent } from '@/util/data/observable'
+import { isSome, type Opt } from '@/util/data/opt'
+import { Err, Ok, type Result } from '@/util/data/result'
 import { ReactiveMapping } from '@/util/database/reactiveDb'
 import {
   AsyncQueue,
@@ -10,10 +13,7 @@ import {
   createWebsocketClient,
   rpcWithRetries as lsRpcWithRetries,
 } from '@/util/net'
-import { nextEvent } from '@/util/observable'
-import { isSome, type Opt } from '@/util/opt'
 import { tryQualifiedName } from '@/util/qualifiedName'
-import { Err, Ok, type Result } from '@/util/result'
 import { Client, RequestManager } from '@open-rpc/client-js'
 import { computedAsync } from '@vueuse/core'
 import * as array from 'lib0/array'
diff --git a/app/gui2/src/stores/project/visualizationDataRegistry.ts b/app/gui2/src/stores/project/visualizationDataRegistry.ts
index aac9f149eb7..ee6cff1ce93 100644
--- a/app/gui2/src/stores/project/visualizationDataRegistry.ts
+++ b/app/gui2/src/stores/project/visualizationDataRegistry.ts
@@ -1,5 +1,5 @@
 import type { ExecutionContext } from '@/stores/project'
-import { Err, Ok, type Result } from '@/util/result'
+import { Err, Ok, type Result } from '@/util/data/result'
 import { OutboundPayload, VisualizationUpdate } from 'shared/binaryProtocol'
 import type { DataServer } from 'shared/dataServer'
 import type {
diff --git a/app/gui2/src/stores/suggestionDatabase/__tests__/lsUpdate.test.ts b/app/gui2/src/stores/suggestionDatabase/__tests__/lsUpdate.test.ts
index def4376bbe0..fbee671f41e 100644
--- a/app/gui2/src/stores/suggestionDatabase/__tests__/lsUpdate.test.ts
+++ b/app/gui2/src/stores/suggestionDatabase/__tests__/lsUpdate.test.ts
@@ -1,9 +1,9 @@
 import { SuggestionDb, type Group } from '@/stores/suggestionDatabase'
 import { SuggestionKind, entryQn, type SuggestionEntry } from '@/stores/suggestionDatabase/entry'
 import { applyUpdates } from '@/stores/suggestionDatabase/lsUpdate'
+import { unwrap } from '@/util/data/result'
 import { parseDocs } from '@/util/docParser'
 import { tryIdentifier, tryQualifiedName, type QualifiedName } from '@/util/qualifiedName'
-import { unwrap } from '@/util/result'
 import * as lsTypes from 'shared/languageServerTypes/suggestions'
 import { expect, test } from 'vitest'
 
diff --git a/app/gui2/src/stores/suggestionDatabase/documentation.ts b/app/gui2/src/stores/suggestionDatabase/documentation.ts
index 2fe57cd58fa..4fcc28a5ec7 100644
--- a/app/gui2/src/stores/suggestionDatabase/documentation.ts
+++ b/app/gui2/src/stores/suggestionDatabase/documentation.ts
@@ -1,10 +1,10 @@
 import type { Group } from '@/stores/suggestionDatabase'
-import { findIndexOpt } from '@/util/array'
+import { findIndexOpt } from '@/util/data/array'
+import { isSome, type Opt } from '@/util/data/opt'
+import { unwrap } from '@/util/data/result'
 import { parseDocs, type Doc } from '@/util/docParser'
 import type { Icon } from '@/util/iconName'
-import { isSome, type Opt } from '@/util/opt'
 import { tryQualifiedName, type QualifiedName } from '@/util/qualifiedName'
-import { unwrap } from '@/util/result'
 
 export interface DocumentationData {
   documentation: Doc.Section[]
diff --git a/app/gui2/src/stores/suggestionDatabase/index.ts b/app/gui2/src/stores/suggestionDatabase/index.ts
index 3c51f7418c0..bd1c4ebeefc 100644
--- a/app/gui2/src/stores/suggestionDatabase/index.ts
+++ b/app/gui2/src/stores/suggestionDatabase/index.ts
@@ -1,9 +1,9 @@
 import { useProjectStore } from '@/stores/project'
 import { entryQn, type SuggestionEntry, type SuggestionId } from '@/stores/suggestionDatabase/entry'
 import { applyUpdates, entryFromLs } from '@/stores/suggestionDatabase/lsUpdate'
+import { type Opt } from '@/util/data/opt'
 import { ReactiveDb, ReactiveIndex } from '@/util/database/reactiveDb'
 import { AsyncQueue, rpcWithRetries } from '@/util/net'
-import { type Opt } from '@/util/opt'
 import { qnJoin, qnParent, tryQualifiedName, type QualifiedName } from '@/util/qualifiedName'
 import { defineStore } from 'pinia'
 import { LanguageServer } from 'shared/languageServer'
diff --git a/app/gui2/src/stores/suggestionDatabase/lsUpdate.ts b/app/gui2/src/stores/suggestionDatabase/lsUpdate.ts
index 94d90fe55f9..7dfd593a5ec 100644
--- a/app/gui2/src/stores/suggestionDatabase/lsUpdate.ts
+++ b/app/gui2/src/stores/suggestionDatabase/lsUpdate.ts
@@ -11,9 +11,10 @@ import {
   type Typename,
 } from '@/stores/suggestionDatabase/entry'
 import { assert, assertNever } from '@/util/assert'
+import { type Opt } from '@/util/data/opt'
+import { Err, Ok, withContext, type Result } from '@/util/data/result'
 import type { Doc } from '@/util/docParser'
 import type { Icon } from '@/util/iconName'
-import { type Opt } from '@/util/opt'
 import {
   normalizeQualifiedName,
   qnJoin,
@@ -23,7 +24,6 @@ import {
   type Identifier,
   type QualifiedName,
 } from '@/util/qualifiedName'
-import { Err, Ok, withContext, type Result } from '@/util/result'
 import * as lsTypes from 'shared/languageServerTypes/suggestions'
 
 interface UnfinishedEntry {
diff --git a/app/gui2/src/stores/visualization/compilerMessaging.ts b/app/gui2/src/stores/visualization/compilerMessaging.ts
index 16b34ffb976..47d121f11c8 100644
--- a/app/gui2/src/stores/visualization/compilerMessaging.ts
+++ b/app/gui2/src/stores/visualization/compilerMessaging.ts
@@ -17,8 +17,8 @@ import type {
 import Compiler from '@/stores/visualization/compiler?worker'
 import { VisualizationModule } from '@/stores/visualization/runtimeTypes'
 import { assertNever } from '@/util/assert'
-import { toError } from '@/util/error'
-import type { Opt } from '@/util/opt'
+import { toError } from '@/util/data/error'
+import type { Opt } from '@/util/data/opt'
 import { defineKeybinds } from '@/util/shortcuts'
 import { VisualizationContainer, useVisualizationConfig } from '@/util/visualizationBuiltins'
 import { Error as DataError } from 'shared/binaryProtocol'
diff --git a/app/gui2/src/stores/visualization/index.ts b/app/gui2/src/stores/visualization/index.ts
index 733dea14396..845870a3c9a 100644
--- a/app/gui2/src/stores/visualization/index.ts
+++ b/app/gui2/src/stores/visualization/index.ts
@@ -21,8 +21,10 @@ import {
   type VisualizationId,
 } from '@/stores/visualization/metadata'
 import type { VisualizationModule } from '@/stores/visualization/runtimeTypes'
+import type { Opt } from '@/util/data/opt'
+import { isUrlString } from '@/util/data/urlString'
+import { isIconName } from '@/util/iconName'
 import { rpcWithRetries } from '@/util/net'
-import type { Opt } from '@/util/opt'
 import { defineStore } from 'pinia'
 import type { Event as LSEvent, VisualizationConfiguration } from 'shared/languageServerTypes'
 import type { ExprId, VisualizationIdentifier } from 'shared/yjsModel'
@@ -226,7 +228,8 @@ export const useVisualizationStore = defineStore('visualization', () => {
   }
 
   function icon(type: VisualizationIdentifier) {
-    return metadata.get(toVisualizationId(type))?.icon
+    const icon = metadata.get(toVisualizationId(type))?.icon
+    return icon && (isIconName(icon) || isUrlString(icon)) ? icon : undefined
   }
 
   function get(meta: VisualizationIdentifier, ignoreCache = false) {
diff --git a/app/gui2/src/stores/visualization/metadata.ts b/app/gui2/src/stores/visualization/metadata.ts
index 807a1234ff3..a1207fbe89a 100644
--- a/app/gui2/src/stores/visualization/metadata.ts
+++ b/app/gui2/src/stores/visualization/metadata.ts
@@ -1,6 +1,6 @@
 import type { VisualizationModule } from '@/stores/visualization/runtimeTypes'
+import type { Opt } from '@/util/data/opt'
 import { ReactiveDb, ReactiveIndex } from '@/util/database/reactiveDb'
-import type { Opt } from '@/util/opt'
 import type { VisualizationIdentifier } from 'shared/yjsModel'
 
 export interface VisualizationMetadata
diff --git a/app/gui2/src/stores/visualization/runtimeTypes.ts b/app/gui2/src/stores/visualization/runtimeTypes.ts
index 5804d401907..d2c5d238234 100644
--- a/app/gui2/src/stores/visualization/runtimeTypes.ts
+++ b/app/gui2/src/stores/visualization/runtimeTypes.ts
@@ -1,6 +1,5 @@
-import iconNames from '@/util/iconList.json'
-import type { Icon } from '@/util/iconName'
-import type { URLString } from '@/util/urlString'
+import { isUrlString } from '@/util/data/urlString'
+import { isIconName } from '@/util/iconName'
 import type { DefineComponent, PropType } from 'vue'
 import * as z from 'zod'
 
@@ -42,8 +41,7 @@ export const VisualizationModule = z.object({
   icon: z
     .string()
     .transform((s) => {
-      if (iconNames.includes(s)) return s as Icon
-      else if (s.includes(':')) return s as URLString
+      if (isIconName(s) || isUrlString(s)) return s
       console.warn(`Invalid icon name '${s}'`)
       return undefined
     })
diff --git a/app/gui2/src/util/README.md b/app/gui2/src/util/README.md
new file mode 100644
index 00000000000..4a7fcebf7cc
--- /dev/null
+++ b/app/gui2/src/util/README.md
@@ -0,0 +1,4 @@
+# Utilities
+
+This folder contains code (mostly utility functions) that are not related to any
+specific part of the UI.
diff --git a/app/gui2/src/util/__tests__/array.test.ts b/app/gui2/src/util/__tests__/array.test.ts
index c3e5a328633..4d0b1ecaeff 100644
--- a/app/gui2/src/util/__tests__/array.test.ts
+++ b/app/gui2/src/util/__tests__/array.test.ts
@@ -1,4 +1,4 @@
-import { partitionPoint } from '@/util/array'
+import { partitionPoint } from '@/util/data/array'
 import { fc, test as fcTest } from '@fast-check/vitest'
 import { expect } from 'vitest'
 
diff --git a/app/gui2/src/util/__tests__/range.test.ts b/app/gui2/src/util/__tests__/range.test.ts
index 40b3d0cdb0b..80794c8e2a1 100644
--- a/app/gui2/src/util/__tests__/range.test.ts
+++ b/app/gui2/src/util/__tests__/range.test.ts
@@ -1,4 +1,4 @@
-import { MultiRange, Range } from '@/util/range'
+import { MultiRange, Range } from '@/util/data/range'
 import { expect, test } from 'vitest'
 
 function r(...r: [start: number, end: number][]) {
diff --git a/app/gui2/src/util/__tests__/reactivity.test.ts b/app/gui2/src/util/__tests__/reactivity.test.ts
index bff3d4037a6..4b14711ed05 100644
--- a/app/gui2/src/util/__tests__/reactivity.test.ts
+++ b/app/gui2/src/util/__tests__/reactivity.test.ts
@@ -1,6 +1,6 @@
+import { LazySyncEffectSet } from '@/util/reactivity'
 import { expect, test, vi } from 'vitest'
 import { nextTick, reactive, ref } from 'vue'
-import { LazySyncEffectSet } from '../reactivity'
 
 test('LazySyncEffectSet', async () => {
   const lazySet = new LazySyncEffectSet()
diff --git a/app/gui2/src/util/ast/__tests__/aliasAnalysis.test.ts b/app/gui2/src/util/ast/__tests__/aliasAnalysis.test.ts
index ca14c4c99af..c0905121650 100644
--- a/app/gui2/src/util/ast/__tests__/aliasAnalysis.test.ts
+++ b/app/gui2/src/util/ast/__tests__/aliasAnalysis.test.ts
@@ -25,12 +25,11 @@
  * All unannotated identifiers are assumed to preexist in the environment (captured from an external scope or imports).
  */
 
-import type { ContentRange } from '@/../../../../shared/yjsModel'
 import { assertDefined } from '@/util/assert'
+import { AliasAnalyzer } from '@/util/ast/aliasAnalysis'
 import { MappedKeyMap, MappedSet } from '@/util/containers'
+import { IdMap, type ContentRange } from 'shared/yjsModel'
 import { expect, test } from 'vitest'
-import { IdMap } from '../../../../shared/yjsModel'
-import { AliasAnalyzer } from '../aliasAnalysis'
 
 /** The type of annotation. */
 enum AnnotationType {
@@ -57,7 +56,7 @@ function parseAnnotations(annotatedCode: string): {
   unannotatedCode: string
   annotations: MappedKeyMap<ContentRange, Annotation>
 } {
-  const annotations = new MappedKeyMap(IdMap.keyForRange)
+  const annotations = new MappedKeyMap<ContentRange, Annotation>(IdMap.keyForRange)
 
   // Iterate over all annotations (either bindings or usages).
   // I.e. we want to cover both `«1,x»` and `»1,x«` cases, while keeping the track of the annotation type.
@@ -69,7 +68,14 @@ function parseAnnotations(annotatedCode: string): {
 
   const unannotatedCode = annotatedCode.replace(
     annotationRegex,
-    (match, bindingPrefix, bindingName, usagePrefix, usageName, offset) => {
+    (
+      match,
+      bindingPrefix: string | undefined,
+      bindingName: string | undefined,
+      usagePrefix: string | undefined,
+      usageName: string | undefined,
+      offset: number,
+    ) => {
       console.log(`Processing annotated identifier ${match}.`)
 
       // Sanity check: either both binding prefix and name are present, or both usage prefix and name are present.
@@ -78,13 +84,13 @@ function parseAnnotations(annotatedCode: string): {
       expect(usagePrefix != null).toBe(usageName != null)
       expect(bindingPrefix != null).not.toBe(usagePrefix != null)
 
-      const id = parseInt(bindingPrefix ?? usagePrefix, 10)
-      const name = bindingName ?? usageName
+      const id = parseInt(bindingPrefix ?? usagePrefix ?? '0', 10)
+      const name = bindingName ?? usageName ?? ''
       const kind = bindingPrefix != null ? AnnotationType.Binding : AnnotationType.Usage
 
       const start = offset - accumulatedOffset
       const end = start + name.length
-      const range = [start, end]
+      const range: ContentRange = [start, end]
 
       const annotation = new Annotation(kind, id)
       accumulatedOffset += match.length - name.length
diff --git a/app/gui2/src/util/ast/__tests__/ast.test.ts b/app/gui2/src/util/ast/__tests__/ast.test.ts
index 77448455e18..d956fce465e 100644
--- a/app/gui2/src/util/ast/__tests__/ast.test.ts
+++ b/app/gui2/src/util/ast/__tests__/ast.test.ts
@@ -1,6 +1,4 @@
 import { Token, Tree } from '@/generated/ast'
-import type { LazyObject } from '@/util/parserSupport'
-import { assert, expect, test } from 'vitest'
 import {
   astContainingChar,
   childrenAstNodes,
@@ -11,7 +9,9 @@ import {
   readAstSpan,
   readTokenSpan,
   walkRecursive,
-} from '..'
+} from '@/util/ast'
+import type { LazyObject } from '@/util/parserSupport'
+import { assert, expect, test } from 'vitest'
 
 function validateSpans(obj: LazyObject, initialPos?: number): number {
   const state = { pos: initialPos ?? 0 }
diff --git a/app/gui2/src/util/ast/__tests__/callTree.test.ts b/app/gui2/src/util/ast/__tests__/callTree.test.ts
index 5d4ca7e4267..8b0ed226b12 100644
--- a/app/gui2/src/util/ast/__tests__/callTree.test.ts
+++ b/app/gui2/src/util/ast/__tests__/callTree.test.ts
@@ -1,7 +1,7 @@
 import { SuggestionKind, type SuggestionEntry } from '@/stores/suggestionDatabase/entry'
 import { Ast } from '@/util/ast'
 import { ArgumentApplication, ArgumentPlaceholder } from '@/util/callTree'
-import { isSome } from '@/util/opt'
+import { isSome } from '@/util/data/opt'
 import { type Identifier, type QualifiedName } from '@/util/qualifiedName'
 import type { MethodCall } from 'shared/languageServerTypes'
 import { assert, expect, test } from 'vitest'
diff --git a/app/gui2/src/util/ast/abstract.ts b/app/gui2/src/util/ast/abstract.ts
index ca00356fac5..be79fc904ed 100644
--- a/app/gui2/src/util/ast/abstract.ts
+++ b/app/gui2/src/util/ast/abstract.ts
@@ -1,12 +1,11 @@
 import * as RawAst from '@/generated/ast'
 import { parseEnso } from '@/util/ast'
 import { AstExtended as RawAstExtended } from '@/util/ast/extended'
+import { Err, Ok, type Result } from '@/util/data/result'
 import type { LazyObject } from '@/util/parserSupport'
-import { Err, Ok, type Result } from '@/util/result'
 import * as random from 'lib0/random'
+import { IdMap, type ExprId } from 'shared/yjsModel'
 import { reactive } from 'vue'
-import type { ExprId } from '../../../shared/yjsModel'
-import { IdMap } from '../../../shared/yjsModel'
 
 interface Module {
   get(id: AstId): Ast | null
diff --git a/app/gui2/src/util/ast/aliasAnalysis.ts b/app/gui2/src/util/ast/aliasAnalysis.ts
index 7a42e44d61b..eef1a7d4c14 100644
--- a/app/gui2/src/util/ast/aliasAnalysis.ts
+++ b/app/gui2/src/util/ast/aliasAnalysis.ts
@@ -7,11 +7,9 @@ import {
   readAstOrTokenSpan,
   readTokenSpan,
 } from '@/util/ast'
-
 import { MappedKeyMap, MappedSet, NonEmptyStack } from '@/util/containers'
-import type { LazyObject } from '@/util/parserSupport.ts'
-import type { ContentRange } from '../../../shared/yjsModel'
-import { IdMap, rangeIsBefore } from '../../../shared/yjsModel'
+import type { LazyObject } from '@/util/parserSupport'
+import { IdMap, rangeIsBefore, type ContentRange } from 'shared/yjsModel'
 
 const ACCESSOR_OPERATOR = '.'
 
diff --git a/app/gui2/src/util/ast/extended.ts b/app/gui2/src/util/ast/extended.ts
index 5b600c84b91..8b42059052c 100644
--- a/app/gui2/src/util/ast/extended.ts
+++ b/app/gui2/src/util/ast/extended.ts
@@ -1,11 +1,6 @@
 import * as Ast from '@/generated/ast'
 import { Token, Tree } from '@/generated/ast'
 import { assert } from '@/util/assert'
-import * as encoding from 'lib0/encoding'
-import { digest } from 'lib0/hash/sha256'
-import * as map from 'lib0/map'
-import type { ContentRange, ExprId, IdMap } from 'shared/yjsModel'
-import { markRaw } from 'vue'
 import {
   childrenAstNodesOrTokens,
   debugAst,
@@ -15,8 +10,13 @@ import {
   visitGenerator,
   visitRecursive,
   walkRecursive,
-} from '.'
-import type { Opt } from '../opt'
+} from '@/util/ast'
+import type { Opt } from '@/util/data/opt'
+import * as encoding from 'lib0/encoding'
+import * as sha256 from 'lib0/hash/sha256'
+import * as map from 'lib0/map'
+import type { ContentRange, ExprId, IdMap } from 'shared/yjsModel'
+import { markRaw } from 'vue'
 
 type ExtractType<V, T> = T extends ReadonlyArray<infer Ts>
   ? Extract<V, { type: Ts }>
@@ -218,7 +218,7 @@ class AstExtendedCtx<HasIdMap extends boolean> {
   getHash(ast: AstExtended<Tree | Token, boolean>) {
     const key = AstExtendedCtx.getHashKey(ast)
     return map.setIfUndefined(this.contentHashes, key, () =>
-      digest(
+      sha256.digest(
         encoding.encode((encoder) => {
           const whitespace = ast.whitespaceLength()
           encoding.writeUint32(encoder, whitespace)
diff --git a/app/gui2/src/util/ast/index.ts b/app/gui2/src/util/ast/index.ts
index d68d4b68160..b721eb6fe87 100644
--- a/app/gui2/src/util/ast/index.ts
+++ b/app/gui2/src/util/ast/index.ts
@@ -1,12 +1,12 @@
 import * as RawAst from '@/generated/ast'
 import { assert } from '@/util/assert'
 import * as Ast from '@/util/ast/abstract'
+import { AstExtended as RawAstExtended } from '@/util/ast/extended'
+import { isResult, mapOk } from '@/util/data/result'
 import { parse } from '@/util/ffi'
 import { LazyObject, LazySequence } from '@/util/parserSupport'
-import { isResult, mapOk } from '@/util/result'
 import * as map from 'lib0/map'
 import type { ContentRange } from 'shared/yjsModel'
-import { AstExtended as RawAstExtended } from './extended'
 
 export { Ast, RawAst, RawAstExtended }
 
diff --git a/app/gui2/src/util/ast/opr.ts b/app/gui2/src/util/ast/opr.ts
index 6ae46307f93..c9de9f4808b 100644
--- a/app/gui2/src/util/ast/opr.ts
+++ b/app/gui2/src/util/ast/opr.ts
@@ -1,6 +1,6 @@
 import { assert } from '@/util/assert'
 import { RawAst, RawAstExtended } from '@/util/ast'
-import { zip } from '@/util/iterable'
+import { zip } from '@/util/data/iterable'
 import { mapIterator } from 'lib0/iterator'
 
 /** An operand of one of the applications inside `GeneralOprApp` */
diff --git a/app/gui2/src/util/autoBlur.ts b/app/gui2/src/util/autoBlur.ts
index 06c80fd67f9..9cefef5b64b 100644
--- a/app/gui2/src/util/autoBlur.ts
+++ b/app/gui2/src/util/autoBlur.ts
@@ -1,4 +1,4 @@
-import { useEvent } from '@/util/events'
+import { useEvent } from '@/composables/events'
 import type { Ref } from 'vue'
 
 export function useAutoBlur(root: Ref<HTMLElement | SVGElement | MathMLElement | undefined>) {
diff --git a/app/gui2/src/util/callTree.ts b/app/gui2/src/util/callTree.ts
index 7a2e5e915e8..1bee5d9ba6b 100644
--- a/app/gui2/src/util/callTree.ts
+++ b/app/gui2/src/util/callTree.ts
@@ -1,8 +1,8 @@
 import type { ForcePort } from '@/providers/portInfo'
 import type { SuggestionEntry, SuggestionEntryArgument } from '@/stores/suggestionDatabase/entry'
+import { Ast } from '@/util/ast'
+import { tryGetIndex } from '@/util/data/array'
 import type { MethodCall } from 'shared/languageServerTypes'
-import { tryGetIndex } from './array'
-import { Ast } from './ast'
 
 export const enum ApplicationKind {
   Prefix,
diff --git a/app/gui2/src/util/compare.ts b/app/gui2/src/util/compare.ts
index 40109cf3212..039c24a216a 100644
--- a/app/gui2/src/util/compare.ts
+++ b/app/gui2/src/util/compare.ts
@@ -1,4 +1,4 @@
-import { isNone, isSome, type Opt } from '@/util/opt'
+import { isNone, isSome, type Opt } from '@/util/data/opt'
 
 /**
  * Compare two optional numbers. Returns a comparision result like specified for `sort`
diff --git a/app/gui2/src/util/containers.ts b/app/gui2/src/util/containers.ts
index 21de8c29d4e..96342e087d7 100644
--- a/app/gui2/src/util/containers.ts
+++ b/app/gui2/src/util/containers.ts
@@ -1,5 +1,5 @@
-import type { NonEmptyArray } from '@/util/array.ts'
 import { assertDefined, assertEqual } from '@/util/assert'
+import type { NonEmptyArray } from '@/util/data/array'
 import { mapIterator } from 'lib0/iterator'
 
 /**
diff --git a/app/gui2/src/util/crdt.ts b/app/gui2/src/util/crdt.ts
index 825359ef832..16fa193e1b6 100644
--- a/app/gui2/src/util/crdt.ts
+++ b/app/gui2/src/util/crdt.ts
@@ -1,4 +1,4 @@
-import type { Opt } from '@/util/opt'
+import type { Opt } from '@/util/data/opt'
 import { watchEffect, type Ref } from 'vue'
 import type { Awareness } from 'y-protocols/awareness'
 import { WebsocketProvider } from 'y-websocket'
diff --git a/app/gui2/src/util/data/README.md b/app/gui2/src/util/data/README.md
new file mode 100644
index 00000000000..c8d4cc9f381
--- /dev/null
+++ b/app/gui2/src/util/data/README.md
@@ -0,0 +1,7 @@
+# Data structures
+
+This folder contains:
+
+- classes defining data structures
+- branded types (newtypes) for specific data types
+- utility functions for data structures
diff --git a/app/gui2/src/util/array.ts b/app/gui2/src/util/data/array.ts
similarity index 95%
rename from app/gui2/src/util/array.ts
rename to app/gui2/src/util/data/array.ts
index bc5ae852d88..c5d8dbf1513 100644
--- a/app/gui2/src/util/array.ts
+++ b/app/gui2/src/util/data/array.ts
@@ -1,4 +1,6 @@
-import type { Opt } from './opt'
+/** @file Functions for querying and manipulating arrays. */
+
+import type { Opt } from '@/util/data/opt'
 
 /** An array that has at least one element present at all times. */
 export type NonEmptyArray<T> = [T, ...T[]]
diff --git a/app/gui2/src/util/error.ts b/app/gui2/src/util/data/error.ts
similarity index 81%
rename from app/gui2/src/util/error.ts
rename to app/gui2/src/util/data/error.ts
index c46503e8270..25adf383132 100644
--- a/app/gui2/src/util/error.ts
+++ b/app/gui2/src/util/data/error.ts
@@ -1,3 +1,5 @@
+/** @file Functions for creating errors. */
+
 /** Returns {@link Error}s as-is, wraps all other values in an {@link Error}. */
 export function toError(error: unknown) {
   return error instanceof Error ? error : new Error(String(error))
diff --git a/app/gui2/src/util/iterable.ts b/app/gui2/src/util/data/iterable.ts
similarity index 95%
rename from app/gui2/src/util/iterable.ts
rename to app/gui2/src/util/data/iterable.ts
index d27a474fbd4..56f95938ee9 100644
--- a/app/gui2/src/util/iterable.ts
+++ b/app/gui2/src/util/data/iterable.ts
@@ -1,3 +1,5 @@
+/** @file Functions for manipulating {@link Iterable}s. */
+
 export function* empty(): Generator<never> {}
 
 export function* range(start: number, stop: number, step = start <= stop ? 1 : -1) {
diff --git a/app/gui2/src/util/observable.ts b/app/gui2/src/util/data/observable.ts
similarity index 93%
rename from app/gui2/src/util/observable.ts
rename to app/gui2/src/util/data/observable.ts
index dda8f3575b2..9a57180684a 100644
--- a/app/gui2/src/util/observable.ts
+++ b/app/gui2/src/util/data/observable.ts
@@ -1,3 +1,5 @@
+/** Functions for querying {@link ObservableV2}s. */
+
 import type { ObservableV2 } from 'lib0/observable'
 
 export type Events<O extends ObservableV2<any>> = O extends ObservableV2<infer E> ? E : never
diff --git a/app/gui2/src/util/data/opt.ts b/app/gui2/src/util/data/opt.ts
new file mode 100644
index 00000000000..89fd301d9bb
--- /dev/null
+++ b/app/gui2/src/util/data/opt.ts
@@ -0,0 +1,21 @@
+/** @file A value that may be `null` or `undefined`. */
+
+/** Optional value type. This is a replacement for `T | null | undefined` that is more
+ * convenient to use. We do not select a single value to represent "no value", because we are using
+ * libraries that disagree whether `null` (e.g. Yjs) or `undefined` (e.g. Vue) should be used for
+ * that purpose. We want to be compatible with both without needless conversions. In our own code,
+ * we should return `undefined` for "no value", since that is the default value for empty or no
+ * `return` expression. In order to test whether an `Opt<T>` is defined or not, use `x == null` or
+ * `isSome` function.
+ *
+ * Note: For JSON-serialized data, prefer explicit `null` over `undefined`, since `undefined` is
+ * not serializable. Alternatively, use optional field syntax (e.g. `{ x?: number }`). */
+export type Opt<T> = T | null | undefined
+
+export function isSome<T>(value: Opt<T>): value is T {
+  return value != null
+}
+
+export function isNone(value: Opt<any>): value is null | undefined {
+  return value == null
+}
diff --git a/app/gui2/src/util/range.ts b/app/gui2/src/util/data/range.ts
similarity index 96%
rename from app/gui2/src/util/range.ts
rename to app/gui2/src/util/data/range.ts
index bb93403b871..8301ced71fe 100644
--- a/app/gui2/src/util/range.ts
+++ b/app/gui2/src/util/data/range.ts
@@ -1,4 +1,6 @@
-import { partitionPoint } from '@/util/array'
+/** @file Ranges between two numbers, and sets of multiple ranges with gaps between. */
+
+import { partitionPoint } from '@/util/data/array'
 
 export interface RangeWithMatch {
   readonly start: number
diff --git a/app/gui2/src/util/rect.ts b/app/gui2/src/util/data/rect.ts
similarity index 90%
rename from app/gui2/src/util/rect.ts
rename to app/gui2/src/util/data/rect.ts
index f8a1cfd53bc..fdc5e38ad3f 100644
--- a/app/gui2/src/util/rect.ts
+++ b/app/gui2/src/util/data/rect.ts
@@ -1,8 +1,8 @@
-import { Vec2 } from '@/util/vec2'
+/** @file Axis-aligned rectangle. Defined in terms of a top-left point and a size. */
 
-/**
- * Axis-aligned rectangle. Defined in terms of a top-left point and a size.
- */
+import { Vec2 } from '@/util/data/vec2'
+
+/** Axis-aligned rectangle. Defined in terms of a top-left point and a size. */
 export class Rect {
   constructor(
     readonly pos: Vec2,
diff --git a/app/gui2/src/util/result.ts b/app/gui2/src/util/data/result.ts
similarity index 93%
rename from app/gui2/src/util/result.ts
rename to app/gui2/src/util/data/result.ts
index f765eb50507..70869cfef63 100644
--- a/app/gui2/src/util/result.ts
+++ b/app/gui2/src/util/data/result.ts
@@ -1,4 +1,7 @@
-import { isSome, type Opt } from '@/util/opt'
+/** @file A generic type that can either hold a value representing a successful result,
+ * or an error. */
+
+import { isSome, type Opt } from '@/util/data/opt'
 
 export type Result<T = undefined, E = string> =
   | { ok: true; value: T }
diff --git a/app/gui2/src/util/data/urlString.ts b/app/gui2/src/util/data/urlString.ts
new file mode 100644
index 00000000000..55a5c418dc0
--- /dev/null
+++ b/app/gui2/src/util/data/urlString.ts
@@ -0,0 +1,10 @@
+/** @file A URL string. This includes URLs with custom protocols like `data:` URLs, not just `http:`
+ * and `https:`. */
+
+declare const urlStringBrand: unique symbol
+/** A URL string. They */
+export type URLString = string & { [urlStringBrand]: never }
+
+export function isUrlString(value: string): value is URLString {
+  return /^\w+:/.test(value)
+}
diff --git a/app/gui2/src/util/vec2.ts b/app/gui2/src/util/data/vec2.ts
similarity index 84%
rename from app/gui2/src/util/vec2.ts
rename to app/gui2/src/util/data/vec2.ts
index 0de8489d0b9..d4b0353914d 100644
--- a/app/gui2/src/util/vec2.ts
+++ b/app/gui2/src/util/data/vec2.ts
@@ -1,7 +1,8 @@
-/**
- * 2D vector, in no particular reference frame. The exact geometric interpretation of the vector
- * depends on the context where it is used.
- */
+/** @file 2D vector, in no particular reference frame. The exact geometric interpretation of the
+ * vector depends on the context where it is used. */
+
+/** 2D vector, in no particular reference frame. The exact geometric interpretation of the vector
+ * depends on the context where it is used. */
 export class Vec2 {
   constructor(
     readonly x: number,
diff --git a/app/gui2/src/util/net.ts b/app/gui2/src/util/net.ts
index cb28665d2c3..73b23f727f8 100644
--- a/app/gui2/src/util/net.ts
+++ b/app/gui2/src/util/net.ts
@@ -1,3 +1,4 @@
+import { Err, Ok, ResultError, rejectionToResult, type Result } from '@/util/data/result'
 import { WebSocketTransport } from '@open-rpc/client-js'
 import type {
   IJSONRPCNotificationResponse,
@@ -9,7 +10,6 @@ import { wait } from 'lib0/promise'
 import { LsRpcError } from 'shared/languageServer'
 import type { Notifications } from 'shared/languageServerTypes'
 import { WebsocketClient } from 'shared/websocket'
-import { Err, Ok, ResultError, rejectionToResult, type Result } from './result'
 
 export interface BackoffOptions<E> {
   maxRetries?: number
diff --git a/app/gui2/src/util/opt.ts b/app/gui2/src/util/opt.ts
deleted file mode 100644
index 8cea8f665af..00000000000
--- a/app/gui2/src/util/opt.ts
+++ /dev/null
@@ -1,20 +0,0 @@
-/**
- * Optional value type. This is a replacement for `T | null | undefined` that is more convenient to
- * use. We do not select a single value to represent "no value", because we are using libraries that
- * disagree whether `null` (e.g. Yjs) or `undefined` (e.g. Vue) should be used for that purpose. We
- * want to be compatible with both without needless conversions. In our own code, we should return
- * `undefined` for "no value", since that is the default value for empty or no `return` expression.
- * In order to test whether an `Opt<T>` is defined or not, use `x == null` or `isSome` function.
- *
- * Note: For JSON-serialized data, prefer explicit `null` over `undefined`, since `undefined` is
- * not serializable. Alternatively, use optional field syntax (e.g. `{ x?: number }`).
- */
-export type Opt<T> = T | null | undefined
-
-export function isSome<T>(value: Opt<T>): value is T {
-  return value != null
-}
-
-export function isNone(value: Opt<any>): value is null | undefined {
-  return value == null
-}
diff --git a/app/gui2/src/util/parserSupport.ts b/app/gui2/src/util/parserSupport.ts
index 6087a8218cc..7859073e875 100644
--- a/app/gui2/src/util/parserSupport.ts
+++ b/app/gui2/src/util/parserSupport.ts
@@ -1,8 +1,8 @@
 /** This file supports the module in `../generated/ast.ts` that is produced by `parser-codegen`. */
 
-export { type Result } from '@/util/result'
+export { type Result } from '@/util/data/result'
 import { bail } from '@/util/assert'
-import { Err, Ok, type Result } from '@/util/result'
+import { Err, Ok, type Result } from '@/util/data/result'
 
 export type ObjectVisitor = (object: LazyObject) => boolean | void
 export type ObjectAddressVisitor = (view: DataView, address: number) => boolean | void
diff --git a/app/gui2/src/util/qualifiedName.ts b/app/gui2/src/util/qualifiedName.ts
index 366eeea0c71..bd898ec8d27 100644
--- a/app/gui2/src/util/qualifiedName.ts
+++ b/app/gui2/src/util/qualifiedName.ts
@@ -1,4 +1,4 @@
-import { Err, Ok, unwrap, type Result } from '@/util/result'
+import { Err, Ok, unwrap, type Result } from '@/util/data/result'
 
 declare const identifierBrand: unique symbol
 declare const qualifiedNameBrand: unique symbol
diff --git a/app/gui2/src/util/reactivity.ts b/app/gui2/src/util/reactivity.ts
index 6319fb4bd0a..e6a19bb7e6e 100644
--- a/app/gui2/src/util/reactivity.ts
+++ b/app/gui2/src/util/reactivity.ts
@@ -1,3 +1,5 @@
+/** @file Functions for manipulating Vue reactive objects. */
+
 import { nop } from 'lib0/function'
 import {
   callWithErrorHandling,
diff --git a/app/gui2/src/util/shortcuts.ts b/app/gui2/src/util/shortcuts.ts
index a703575a0e5..cfb0895e931 100644
--- a/app/gui2/src/util/shortcuts.ts
+++ b/app/gui2/src/util/shortcuts.ts
@@ -1,4 +1,4 @@
-import { isMacLike } from '@/util/events'
+import { isMacLike } from '@/composables/events'
 
 /** All possible modifier keys. */
 export type ModifierKey = keyof typeof RAW_MODIFIER_FLAG
diff --git a/app/gui2/src/util/urlString.ts b/app/gui2/src/util/urlString.ts
deleted file mode 100644
index 7b48c5dfedf..00000000000
--- a/app/gui2/src/util/urlString.ts
+++ /dev/null
@@ -1 +0,0 @@
-export type URLString = `${string}:${string}`
diff --git a/app/gui2/stories/setup.ts b/app/gui2/stories/setup.ts
index 7825b70074f..5f841195e6b 100644
--- a/app/gui2/stories/setup.ts
+++ b/app/gui2/stories/setup.ts
@@ -1,9 +1,9 @@
 import '@/assets/base.css'
 import { provideGuiConfig } from '@/providers/guiConfig'
 import { provideVisualizationConfig } from '@/providers/visualizationConfig'
+import { Vec2 } from '@/util/data/vec2'
 import { MockTransport } from '@/util/net'
 import type { QualifiedName } from '@/util/qualifiedName'
-import { Vec2 } from '@/util/vec2'
 import { defineSetupVue3 } from '@histoire/plugin-vue'
 import * as random from 'lib0/random'
 import { createPinia } from 'pinia'