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[analyzer][cfe] Share inference-using-bounds routines
Part of #54902 Change-Id: I12282c2492ed9f1220b47fcf8b0d73c93bbfc432 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/401660 Reviewed-by: Erik Ernst <[email protected]> Commit-Queue: Chloe Stefantsova <[email protected]>
1 parent a6b99af commit f49c620

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-353
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‎pkg/_fe_analyzer_shared/lib/src/type_inference/type_analyzer_operations.dart‎

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@@ -5,6 +5,7 @@
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import '../flow_analysis/flow_analysis_operations.dart';
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import '../types/shared_type.dart';
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import 'nullability_suffix.dart';
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import 'type_constraint.dart';
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/// Callback API used by the shared type analyzer to query and manipulate the
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/// client's representation of variables and types.
@@ -698,6 +699,40 @@ abstract interface class TypeAnalyzerOperations<
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/// Returns [type] suffixed with the [suffix].
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TypeStructure withNullabilitySuffixInternal(
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TypeStructure type, NullabilitySuffix suffix);
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TypeConstraintGenerator<
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TypeStructure,
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SharedNamedFunctionParameterStructure<TypeStructure>,
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Variable,
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TypeParameterStructure,
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TypeDeclarationType,
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TypeDeclaration,
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Object>
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createTypeConstraintGenerator(
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{required TypeConstraintGenerationDataForTesting<TypeStructure,
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TypeParameterStructure, Variable, Object>?
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typeConstraintGenerationDataForTesting,
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required List<TypeParameterStructure> typeParametersToInfer,
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required TypeAnalyzerOperations<TypeStructure, Variable,
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TypeParameterStructure, TypeDeclarationType, TypeDeclaration>
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typeAnalyzerOperations,
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required bool inferenceUsingBoundsIsEnabled});
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MergedTypeConstraint<TypeStructure, TypeParameterStructure, Variable,
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TypeDeclarationType, TypeDeclaration>
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mergeInConstraintsFromBound(
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{required TypeParameterStructure typeParameterToInfer,
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required List<TypeParameterStructure> typeParametersToInfer,
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required TypeStructure lower,
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required Map<
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TypeParameterStructure,
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MergedTypeConstraint<TypeStructure, TypeParameterStructure,
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Variable, TypeDeclarationType, TypeDeclaration>>
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inferencePhaseConstraints,
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required TypeConstraintGenerationDataForTesting<TypeStructure,
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TypeParameterStructure, Variable, Object>?
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dataForTesting,
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required bool inferenceUsingBoundsIsEnabled});
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}
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mixin TypeAnalyzerOperationsMixin<
@@ -893,6 +928,96 @@ mixin TypeAnalyzerOperationsMixin<
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SharedTypeView<TypeStructure> type) {
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return new SharedTypeSchemaView(type.unwrapTypeView());
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}
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@override
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MergedTypeConstraint<TypeStructure, TypeParameterStructure, Variable,
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TypeDeclarationType, TypeDeclaration>
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mergeInConstraintsFromBound(
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{required TypeParameterStructure typeParameterToInfer,
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required List<TypeParameterStructure> typeParametersToInfer,
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required TypeStructure lower,
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required Map<
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TypeParameterStructure,
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MergedTypeConstraint<TypeStructure, TypeParameterStructure,
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Variable, TypeDeclarationType, TypeDeclaration>>
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inferencePhaseConstraints,
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required TypeConstraintGenerationDataForTesting<TypeStructure,
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TypeParameterStructure, Variable, Object>?
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dataForTesting,
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required bool inferenceUsingBoundsIsEnabled}) {
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// The type parameter's bound may refer to itself (or other type
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// parameters), so we might have to create an additional constraint.
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// Consider this example from
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// https://github.com/dart-lang/language/issues/3009:
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//
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// class A<X extends A<X>> {}
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// class B extends A<B> {}
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// class C extends B {}
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// void f<X extends A<X>>(X x) {}
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// void main() {
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// f(C()); // should infer f<B>(C()).
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// }
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//
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// In order for `f(C())` to be inferred as `f<B>(C())`, we need to
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// generate the constraint `X <: B`. To do this, we first take the lower
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// constraint we've accumulated so far (which, in this example, is `C`,
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// due to the presence of the actual argument `C()`), and use subtype
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// constraint generation to match it against the explicit bound (which
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// is `A<X>`; hence we perform `C <# A<X>`). If this produces any
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// constraints (i.e. `X <: B` in this example), then they are added to
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// the set of constraints just before choosing the final type.
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TypeStructure typeParameterToInferBound = typeParameterToInfer.bound!;
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// TODO(cstefantsova): Pass [dataForTesting] when
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// [InferenceDataForTesting] is merged with [TypeInferenceResultForTesting].
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TypeConstraintGenerator<
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TypeStructure,
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SharedNamedFunctionParameterStructure<TypeStructure>,
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Variable,
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TypeParameterStructure,
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TypeDeclarationType,
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TypeDeclaration,
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Object> typeConstraintGatherer =
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createTypeConstraintGenerator(
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typeConstraintGenerationDataForTesting: null,
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typeParametersToInfer: typeParametersToInfer,
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typeAnalyzerOperations: this,
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inferenceUsingBoundsIsEnabled: inferenceUsingBoundsIsEnabled);
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typeConstraintGatherer.performSubtypeConstraintGenerationInternal(
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lower, typeParameterToInferBound,
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leftSchema: true, astNodeForTesting: null);
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Map<
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TypeParameterStructure,
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MergedTypeConstraint<
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TypeStructure,
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TypeParameterStructure,
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Variable,
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TypeDeclarationType,
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TypeDeclaration>> constraintsPerTypeVariable =
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typeConstraintGatherer.computeConstraints();
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for (TypeParameterStructure typeParameter
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in constraintsPerTypeVariable.keys) {
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MergedTypeConstraint<TypeStructure, TypeParameterStructure, Variable,
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TypeDeclarationType, TypeDeclaration> constraint =
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constraintsPerTypeVariable[typeParameter]!;
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constraint.origin = new TypeConstraintFromExtendsClause(
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typeParameterName: typeParameterToInfer.displayName,
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boundType: new SharedTypeView(typeParameterToInferBound),
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extendsType: new SharedTypeView(typeParameterToInferBound));
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if (!constraint.isEmpty(this)) {
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MergedTypeConstraint? constraintForParameter =
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inferencePhaseConstraints[typeParameter];
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if (constraintForParameter == null) {
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inferencePhaseConstraints[typeParameter] = constraint;
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} else {
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constraintForParameter.mergeInTypeSchemaUpper(constraint.upper, this);
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constraintForParameter.mergeInTypeSchemaLower(constraint.lower, this);
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}
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}
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}
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return constraintsPerTypeVariable[typeParameterToInfer]!;
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}
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}
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/// Abstract interface of a type constraint generator.
@@ -1832,6 +1957,12 @@ abstract class TypeConstraintGenerator<
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return false;
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}
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/// Returns the set of type constraints that was gathered.
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Map<
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TypeParameterStructure,
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MergedTypeConstraint<TypeStructure, TypeParameterStructure, Variable,
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TypeDeclarationType, TypeDeclaration>> computeConstraints();
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}
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mixin TypeConstraintGeneratorMixin<

‎pkg/_fe_analyzer_shared/lib/src/type_inference/type_constraint.dart‎

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@@ -365,3 +365,41 @@ class UnknownTypeConstraintOrigin<
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return <String>[];
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}
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}
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/// Data structure maintaining intermediate type inference results, such as
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/// type constraints, for testing purposes. Under normal execution, no
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/// instance of this class should be created.
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class TypeConstraintGenerationDataForTesting<
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TypeStructure extends SharedTypeStructure<TypeStructure>,
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TypeParameterStructure extends SharedTypeParameterStructure<TypeStructure>,
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Variable extends Object,
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AstNode extends Object> {
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/// Map from nodes requiring type inference to the generated type constraints
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/// for the node.
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final Map<
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AstNode,
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List<
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GeneratedTypeConstraint<TypeStructure, TypeParameterStructure,
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Variable>>> generatedTypeConstraints = {};
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/// Merges [other] into the receiver, combining the constraints.
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///
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/// The method reuses data structures from [other] whenever possible, to
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/// avoid extra memory allocations. This process is destructive to [other]
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/// because the changes made to the reused structures will be visible to
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/// [other].
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void mergeIn(
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TypeConstraintGenerationDataForTesting<TypeStructure,
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TypeParameterStructure, Variable, AstNode>
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other) {
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for (AstNode node in other.generatedTypeConstraints.keys) {
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List<GeneratedTypeConstraint>? constraints =
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generatedTypeConstraints[node];
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if (constraints != null) {
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constraints.addAll(other.generatedTypeConstraints[node]!);
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} else {
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generatedTypeConstraints[node] = other.generatedTypeConstraints[node]!;
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}
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}
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}
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}

‎pkg/_fe_analyzer_shared/test/mini_ast.dart‎

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@@ -28,11 +28,14 @@ import 'package:_fe_analyzer_shared/src/type_inference/type_analyzer.dart'
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as shared;
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import 'package:_fe_analyzer_shared/src/type_inference/type_analyzer.dart'
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hide MapPatternEntry, RecordPatternField;
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import 'package:_fe_analyzer_shared/src/type_inference/type_constraint.dart';
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import 'package:_fe_analyzer_shared/src/type_inference/type_analyzer_operations.dart';
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import 'package:_fe_analyzer_shared/src/type_inference/variable_bindings.dart';
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import 'package:_fe_analyzer_shared/src/types/shared_type.dart';
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import 'package:test/test.dart';
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import 'type_inference/type_constraint_gatherer_test.dart';
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import 'mini_ir.dart';
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import 'mini_types.dart';
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@@ -3225,6 +3228,21 @@ class MiniAstOperations
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Type withNullabilitySuffixInternal(Type type, NullabilitySuffix modifier) {
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return type.withNullability(modifier);
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}
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@override
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TypeConstraintGenerator<Type, NamedFunctionParameter, Var, TypeParameter,
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Type, String, Node>
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createTypeConstraintGenerator(
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{required TypeConstraintGenerationDataForTesting?
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typeConstraintGenerationDataForTesting,
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required List<TypeParameter> typeParametersToInfer,
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required TypeAnalyzerOperations<Type, Var, TypeParameter, Type,
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String>
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typeAnalyzerOperations,
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required bool inferenceUsingBoundsIsEnabled}) {
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return TypeConstraintGatherer(
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{for (var typeParameter in typeParametersToInfer) typeParameter.name});
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}
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}
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/// Representation of an expression or statement in the pseudo-Dart language

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