Remove most current parse-stage dependency analysis

As described in the previous commit, for the most part this usage of dependency analysis during form parsing is completely redundant to logic performed in the course of evaluating XPath expressions with `engineDOMAdapter`.

In theory, this commit could also delete a bunch of the dependency analysis code along with it. But that code will have value for other purposes. Top of mind: a proper implemenation of cycle detection. I anticipate other use cases as well.

There is still some remaining dependency analysis in active use. This largely focuses on:

- Setting up reactive subscriptions to translation state, updating expressions with `jr:itext` calls when the form’s active language state is changed
- Identifying “notes”, as we’ve modeled them to be value nodes with a `readonly` bind expression which will always evaluate to true

There is certainly still some further simplification left on the table at this commit point. It’s not clear how much the `DependencyContext`/`DependentExpression` abstraction still makes sense. We certainly still use `DependentExpression` to set up reactive computations, but there are other aspects of the conceptual pair which are likely redundant now as well. I’ve left these unaddressed to try to wind up this refactor as quickly as possible.

packages/xforms-engine/src/instance/Note.ts

@@ -83,7 +83,7 @@ export class Note
 			clientStateFactory: this.engineConfig.stateFactory,
 		};
 
-		const isReadonly = createNoteReadonlyThunk(this, definition.bind.readonly);
+		const isReadonly = createNoteReadonlyThunk(this, definition);
 		const noteTextComputation = createNoteText(this, definition.noteTextDefinition);
 
 		let noteText: ComputedNoteText;

packages/xforms-engine/src/lib/reactivity/createNoteReadonlyThunk.ts

@@ -1,31 +1,36 @@
 import type { Accessor } from 'solid-js';
 import type { EvaluationContext } from '../../instance/internal-api/EvaluationContext.ts';
-import type { BindComputationExpression } from '../../parse/expression/BindComputationExpression.ts';
+import type { NoteNodeDefinition } from '../../parse/model/NoteNodeDefinition.ts';
+import { resolveDependencyNodesets } from '../../parse/xpath/dependency-analysis.ts';
 import { createComputedExpression } from './createComputedExpression.ts';
 
 export const createNoteReadonlyThunk = (
 	context: EvaluationContext,
-	readonlyDefinition: BindComputationExpression<'readonly'>
+	definition: NoteNodeDefinition
 ): Accessor<true> => {
-	if (!readonlyDefinition.isConstantTruthyExpression()) {
+	const { reference } = definition.bodyElement;
+	const { readonly } = definition.bind;
+
+	if (!readonly.isConstantTruthyExpression()) {
 		throw new Error('Expected a static readonly expression');
 	}
 
 	let result = true;
 
 	if (import.meta.env.DEV) {
-		const { expression } = readonlyDefinition;
+		const { expression } = readonly;
+		const dependencyReferences = resolveDependencyNodesets(reference, expression);
 
-		if (readonlyDefinition.dependencyReferences.size > 0) {
+		if (dependencyReferences.length > 0) {
 			throw new Error(`Expected expression ${expression} to have no dependencies`);
 		}
 
-		const computedExpression = createComputedExpression(context, readonlyDefinition);
+		const computedExpression = createComputedExpression(context, readonly);
 
 		result = computedExpression();
 
 		if (result !== true) {
-			throw new Error(`Expected expression ${readonlyDefinition.expression} to return true`);
+			throw new Error(`Expected expression ${readonly.expression} to return true`);
 		}
 	}
 

packages/xforms-engine/src/parse/body/control/select/ItemsetNodesetContext.ts

@@ -1,5 +1,4 @@
 import { DependencyContext } from '../../../expression/abstract/DependencyContext.ts';
-import type { AnyDependentExpression } from '../../../expression/abstract/DependentExpression.ts';
 import type { ItemsetDefinition } from './ItemsetDefinition.ts';
 
 export class ItemsetNodesetContext extends DependencyContext {
@@ -19,8 +18,4 @@ export class ItemsetNodesetContext extends DependencyContext {
 		super.isTranslated = value;
 		this.itemset.isTranslated = value;
 	}
-
-	override registerDependentExpression(expression: AnyDependentExpression): void {
-		this.itemset.registerDependentExpression(expression);
-	}
 }

packages/xforms-engine/src/parse/expression/abstract/DependencyContext.ts

@@ -1,28 +1,7 @@
-import type { AnyDependentExpression } from './DependentExpression.ts';
-
 export abstract class DependencyContext {
 	abstract get parentReference(): string | null;
 	abstract get reference(): string | null;
 
-	protected readonly dependentExpressions = new Set<AnyDependentExpression>();
-
-	protected dependencyExpressionsCache: ReadonlySet<string> | null = null;
-
-	get dependencyExpressions(): ReadonlySet<string> {
-		let { dependencyExpressionsCache } = this;
-
-		if (dependencyExpressionsCache == null) {
-			dependencyExpressionsCache = new Set(
-				Array.from(this.dependentExpressions).flatMap((expression) => {
-					return Array.from(expression.dependencyReferences);
-				})
-			);
-			this.dependencyExpressionsCache = dependencyExpressionsCache;
-		}
-
-		return dependencyExpressionsCache;
-	}
-
 	get isTranslated(): boolean {
 		return this._isTranslated;
 	}
@@ -45,9 +24,4 @@ export abstract class DependencyContext {
 
 	// Update note on `set isTranslated` if this internal storage changes.
 	protected _isTranslated = false;
-
-	registerDependentExpression(expression: AnyDependentExpression): void {
-		this.dependencyExpressionsCache = null;
-		this.dependentExpressions.add(expression);
-	}
 }

packages/xforms-engine/src/parse/expression/abstract/DependentExpression.ts

@@ -1,5 +1,4 @@
 import type { EngineXPathEvaluator } from '../../../integration/xpath/EngineXPathEvaluator.ts';
-import { resolveDependencyNodesets } from '../../xpath/dependency-analysis.ts';
 import type {
 	ConstantExpression,
 	ConstantTruthyExpression,
@@ -55,7 +54,6 @@ export interface ConstantTruthyDependentExpression extends ConstantDependentExpr
 }
 
 export abstract class DependentExpression<Type extends DependentExpressionResultType> {
-	readonly dependencyReferences: ReadonlySet<string> = new Set();
 	readonly isTranslated: boolean = false;
 	readonly evaluatorMethod: DependentExpressionEvaluatorMethod<Type>;
 	readonly constantExpression: ConstantExpression | null;
@@ -81,26 +79,17 @@ export abstract class DependentExpression<Type extends DependentExpressionResult
 		this.evaluatorMethod = evaluatorMethodsByResultType[resultType];
 
 		const {
-			ignoreContextReference = false,
 			semanticDependencies = {
 				translations: false,
 			},
 		} = options;
 
-		this.dependencyReferences = new Set(
-			resolveDependencyNodesets(context.reference, expression, {
-				ignoreReferenceToContextPath: ignoreContextReference,
-			})
-		);
-
 		const isTranslated = semanticDependencies.translations && isTranslationExpression(expression);
 
 		if (isTranslated) {
 			this.isTranslated = true;
 			context.isTranslated = true;
 		}
-
-		context.registerDependentExpression(this);
 	}
 
 	isConstantExpression(): this is ConstantDependentExpression<Type> {

packages/xforms-engine/src/parse/model/DescendentNodeDefinition.ts

@@ -29,7 +29,6 @@ export abstract class DescendentNodeDefinition<
 
 	readonly root: RootDefinition;
 	readonly nodeset: string;
-	readonly dependencyExpressions: ReadonlySet<string>;
 	readonly isTranslated: boolean = false;
 
 	constructor(
@@ -43,11 +42,6 @@ export abstract class DescendentNodeDefinition<
 		if (bind.isTranslated || bodyElement?.isTranslated) {
 			this.isTranslated = true;
 		}
-
-		this.dependencyExpressions = new Set([
-			...bind.dependencyExpressions,
-			...(bodyElement?.dependencyExpressions ?? []),
-		]);
 	}
 }
 

packages/xforms-engine/src/parse/model/NodeDefinition.ts

@@ -121,10 +121,7 @@ export interface NodeDefinition<Type extends NodeDefinitionType> {
 	readonly nodeset: string;
 	readonly nodeName: string;
 	readonly bodyElement: AnyBodyElementDefinition | RepeatElementDefinition | null;
-
 	readonly isTranslated: boolean;
-	readonly dependencyExpressions: ReadonlySet<string>;
-
 	readonly root: RootDefinition;
 	readonly parent: NodeParent<Type>;
 	readonly children: NodeChildren<Type>;

packages/xforms-engine/src/parse/model/RootDefinition.ts

@@ -27,7 +27,6 @@ export class RootDefinition implements NodeDefinition<'root'> {
 	readonly defaultValue = null;
 
 	readonly isTranslated = false;
-	readonly dependencyExpressions: ReadonlySet<string> = new Set<string>();
 
 	constructor(
 		protected readonly form: XFormDefinition,

packages/xforms-engine/src/parse/text/abstract/TextRangeDefinition.ts

@@ -2,7 +2,6 @@ import type { LocalNamedElement } from '@getodk/common/types/dom.ts';
 import type { TextRole } from '../../../client/TextRange.ts';
 import type { XFormDefinition } from '../../../parse/XFormDefinition.ts';
 import { DependencyContext } from '../../expression/abstract/DependencyContext.ts';
-import type { AnyDependentExpression } from '../../expression/abstract/DependentExpression.ts';
 import type { AnyTextChunkExpression } from '../../expression/abstract/TextChunkExpression.ts';
 import type { AnyMessageDefinition } from '../MessageDefinition.ts';
 import type { AnyTextElementDefinition } from './TextElementDefinition.ts';
@@ -52,11 +51,6 @@ export abstract class TextRangeDefinition<Role extends TextRole> extends Depende
 		this.parentReference = ownerContext.parentReference;
 	}
 
-	override registerDependentExpression(expression: AnyDependentExpression): void {
-		this.ownerContext.registerDependentExpression(expression);
-		super.registerDependentExpression(expression);
-	}
-
 	toJSON(): object {
 		const { form, ownerContext, ...rest } = this;