Add Type::getLastIterableValueType()

src/Type/Accessory/AccessoryArrayListType.php

@@ -157,6 +157,16 @@ public function getIterableValueType(): Type
 		return new MixedType();
 	}
 
+	public function getFirstIterableValueType(): Type
+	{
+		return new MixedType();
+	}
+
+	public function getLastIterableValueType(): Type
+	{
+		return new MixedType();
+	}
+
 	public function isArray(): TrinaryLogic
 	{
 		return TrinaryLogic::createYes();

src/Type/Accessory/NonEmptyArrayType.php

@@ -146,6 +146,16 @@ public function getIterableValueType(): Type
 		return new MixedType();
 	}
 
+	public function getFirstIterableValueType(): Type
+	{
+		return new MixedType();
+	}
+
+	public function getLastIterableValueType(): Type
+	{
+		return new MixedType();
+	}
+
 	public function isArray(): TrinaryLogic
 	{
 		return TrinaryLogic::createYes();

src/Type/Accessory/OversizedArrayType.php

@@ -145,6 +145,16 @@ public function getIterableValueType(): Type
 		return new MixedType();
 	}
 
+	public function getFirstIterableValueType(): Type
+	{
+		return new MixedType();
+	}
+
+	public function getLastIterableValueType(): Type
+	{
+		return new MixedType();
+	}
+
 	public function isArray(): TrinaryLogic
 	{
 		return TrinaryLogic::createYes();

src/Type/ArrayType.php

@@ -213,6 +213,16 @@ public function getIterableValueType(): Type
 		return $this->getItemType();
 	}
 
+	public function getFirstIterableValueType(): Type
+	{
+		return $this->getItemType();
+	}
+
+	public function getLastIterableValueType(): Type
+	{
+		return $this->getItemType();
+	}
+
 	public function isArray(): TrinaryLogic
 	{
 		return TrinaryLogic::createYes();

src/Type/Constant/ConstantArrayType.php

@@ -261,30 +261,16 @@ public function getValueTypes(): array
 		return $this->valueTypes;
 	}
 
+	/** @deprecated Use getFirstIterableValueType() instead */
 	public function getFirstValueType(): Type
 	{
-		$valueTypes = [];
-		foreach ($this->valueTypes as $i => $valueType) {
-			$valueTypes[] = $valueType;
-			if (!$this->isOptionalKey($i)) {
-				break;
-			}
-		}
-
-		return TypeCombinator::union(...$valueTypes);
+		return $this->getFirstIterableValueType();
 	}
 
+	/** @deprecated Use getLastIterableValueType() instead */
 	public function getLastValueType(): Type
 	{
-		$valueTypes = [];
-		for ($i = count($this->keyTypes) - 1; $i >= 0; $i--) {
-			$valueTypes[] = $this->valueTypes[$i];
-			if (!$this->isOptionalKey($i)) {
-				break;
-			}
-		}
-
-		return TypeCombinator::union(...$valueTypes);
+		return $this->getLastIterableValueType();
 	}
 
 	public function isOptionalKey(int $i): bool
@@ -712,6 +698,32 @@ public function isIterableAtLeastOnce(): TrinaryLogic
 		return TrinaryLogic::createMaybe();
 	}
 
+	public function getFirstIterableValueType(): Type
+	{
+		$valueTypes = [];
+		foreach ($this->valueTypes as $i => $valueType) {
+			$valueTypes[] = $valueType;
+			if (!$this->isOptionalKey($i)) {
+				break;
+			}
+		}
+
+		return TypeCombinator::union(...$valueTypes);
+	}
+
+	public function getLastIterableValueType(): Type
+	{
+		$valueTypes = [];
+		for ($i = count($this->keyTypes) - 1; $i >= 0; $i--) {
+			$valueTypes[] = $this->valueTypes[$i];
+			if (!$this->isOptionalKey($i)) {
+				break;
+			}
+		}
+
+		return TypeCombinator::union(...$valueTypes);
+	}
+
 	public function isList(): TrinaryLogic
 	{
 		if ($this->isList) {

src/Type/IntersectionType.php

@@ -416,6 +416,16 @@ public function getIterableValueType(): Type
 		return $this->intersectTypes(static fn (Type $type): Type => $type->getIterableValueType());
 	}
 
+	public function getFirstIterableValueType(): Type
+	{
+		return $this->intersectTypes(static fn (Type $type): Type => $type->getFirstIterableValueType());
+	}
+
+	public function getLastIterableValueType(): Type
+	{
+		return $this->intersectTypes(static fn (Type $type): Type => $type->getLastIterableValueType());
+	}
+
 	public function isArray(): TrinaryLogic
 	{
 		return $this->intersectResults(static fn (Type $type): TrinaryLogic => $type->isArray());

src/Type/MixedType.php

@@ -376,6 +376,16 @@ public function getIterableValueType(): Type
 		return new self($this->isExplicitMixed);
 	}
 
+	public function getFirstIterableValueType(): Type
+	{
+		return new self($this->isExplicitMixed);
+	}
+
+	public function getLastIterableValueType(): Type
+	{
+		return new self($this->isExplicitMixed);
+	}
+
 	public function isOffsetAccessible(): TrinaryLogic
 	{
 		if ($this->subtractedType !== null) {

src/Type/Php/ArrayPointerFunctionsDynamicReturnTypeExtension.php

@@ -5,7 +5,6 @@
 use PhpParser\Node\Expr\FuncCall;
 use PHPStan\Analyser\Scope;
 use PHPStan\Reflection\FunctionReflection;
-use PHPStan\Reflection\ParametersAcceptorSelector;
 use PHPStan\Type\Constant\ConstantBooleanType;
 use PHPStan\Type\DynamicFunctionReturnTypeExtension;
 use PHPStan\Type\Type;
@@ -31,10 +30,10 @@ public function getTypeFromFunctionCall(
 		FunctionReflection $functionReflection,
 		FuncCall $functionCall,
 		Scope $scope,
-	): Type
+	): ?Type
 	{
 		if (count($functionCall->getArgs()) === 0) {
-			return ParametersAcceptorSelector::selectSingle($functionReflection->getVariants())->getReturnType();
+			return null;
 		}
 
 		$argType = $scope->getType($functionCall->getArgs()[0]->value);
@@ -43,27 +42,9 @@ public function getTypeFromFunctionCall(
 			return new ConstantBooleanType(false);
 		}
 
-		$constantArrays = $argType->getConstantArrays();
-		if (count($constantArrays) > 0) {
-			$keyTypes = [];
-			foreach ($constantArrays as $constantArray) {
-				$iterableAtLeastOnce = $argType->isIterableAtLeastOnce();
-				if (!$iterableAtLeastOnce->yes()) {
-					$keyTypes[] = new ConstantBooleanType(false);
-				}
-				if ($iterableAtLeastOnce->no()) {
-					continue;
-				}
-
-				$keyTypes[] = $functionReflection->getName() === 'reset'
-					? $constantArray->getFirstValueType()
-					: $constantArray->getLastValueType();
-			}
-
-			return TypeCombinator::union(...$keyTypes);
-		}
-
-		$itemType = $argType->getIterableValueType();
+		$itemType = $functionReflection->getName() === 'reset'
+			? $argType->getFirstIterableValueType()
+			: $argType->getLastIterableValueType();
 		if ($iterableAtLeastOnce->yes()) {
 			return $itemType;
 		}

src/Type/Php/ArrayPopFunctionReturnTypeExtension.php

@@ -5,12 +5,10 @@
 use PhpParser\Node\Expr\FuncCall;
 use PHPStan\Analyser\Scope;
 use PHPStan\Reflection\FunctionReflection;
-use PHPStan\Reflection\ParametersAcceptorSelector;
 use PHPStan\Type\DynamicFunctionReturnTypeExtension;
 use PHPStan\Type\NullType;
 use PHPStan\Type\Type;
 use PHPStan\Type\TypeCombinator;
-use function count;
 
 class ArrayPopFunctionReturnTypeExtension implements DynamicFunctionReturnTypeExtension
 {
@@ -20,10 +18,10 @@ public function isFunctionSupported(FunctionReflection $functionReflection): boo
 		return $functionReflection->getName() === 'array_pop';
 	}
 
-	public function getTypeFromFunctionCall(FunctionReflection $functionReflection, FuncCall $functionCall, Scope $scope): Type
+	public function getTypeFromFunctionCall(FunctionReflection $functionReflection, FuncCall $functionCall, Scope $scope): ?Type
 	{
 		if (!isset($functionCall->getArgs()[0])) {
-			return ParametersAcceptorSelector::selectSingle($functionReflection->getVariants())->getReturnType();
+			return null;
 		}
 
 		$argType = $scope->getType($functionCall->getArgs()[0]->value);
@@ -32,24 +30,7 @@ public function getTypeFromFunctionCall(FunctionReflection $functionReflection,
 			return new NullType();
 		}
 
-		$constantArrays = $argType->getConstantArrays();
-		if (count($constantArrays) > 0) {
-			$valueTypes = [];
-			foreach ($constantArrays as $constantArray) {
-				$iterableAtLeastOnce = $constantArray->isIterableAtLeastOnce();
-				if (!$iterableAtLeastOnce->yes()) {
-					$valueTypes[] = new NullType();
-				}
-				if ($iterableAtLeastOnce->no()) {
-					continue;
-				}
-				$valueTypes[] = $constantArray->getLastValueType();
-			}
-
-			return TypeCombinator::union(...$valueTypes);
-		}
-
-		$itemType = $argType->getIterableValueType();
+		$itemType = $argType->getLastIterableValueType();
 		if ($iterableAtLeastOnce->yes()) {
 			return $itemType;
 		}

src/Type/Php/ArrayShiftFunctionReturnTypeExtension.php

@@ -5,12 +5,10 @@
 use PhpParser\Node\Expr\FuncCall;
 use PHPStan\Analyser\Scope;
 use PHPStan\Reflection\FunctionReflection;
-use PHPStan\Reflection\ParametersAcceptorSelector;
 use PHPStan\Type\DynamicFunctionReturnTypeExtension;
 use PHPStan\Type\NullType;
 use PHPStan\Type\Type;
 use PHPStan\Type\TypeCombinator;
-use function count;
 
 class ArrayShiftFunctionReturnTypeExtension implements DynamicFunctionReturnTypeExtension
 {
@@ -20,10 +18,10 @@ public function isFunctionSupported(FunctionReflection $functionReflection): boo
 		return $functionReflection->getName() === 'array_shift';
 	}
 
-	public function getTypeFromFunctionCall(FunctionReflection $functionReflection, FuncCall $functionCall, Scope $scope): Type
+	public function getTypeFromFunctionCall(FunctionReflection $functionReflection, FuncCall $functionCall, Scope $scope): ?Type
 	{
 		if (!isset($functionCall->getArgs()[0])) {
-			return ParametersAcceptorSelector::selectSingle($functionReflection->getVariants())->getReturnType();
+			return null;
 		}
 
 		$argType = $scope->getType($functionCall->getArgs()[0]->value);
@@ -32,25 +30,7 @@ public function getTypeFromFunctionCall(FunctionReflection $functionReflection,
 			return new NullType();
 		}
 
-		$constantArrays = $argType->getConstantArrays();
-		if (count($constantArrays) > 0) {
-			$valueTypes = [];
-			foreach ($constantArrays as $constantArray) {
-				$iterableAtLeastOnce = $constantArray->isIterableAtLeastOnce();
-				if (!$iterableAtLeastOnce->yes()) {
-					$valueTypes[] = new NullType();
-				}
-				if ($iterableAtLeastOnce->no()) {
-					continue;
-				}
-
-				$valueTypes[] = $constantArray->getFirstValueType();
-			}
-
-			return TypeCombinator::union(...$valueTypes);
-		}
-
-		$itemType = $argType->getIterableValueType();
+		$itemType = $argType->getFirstIterableValueType();
 		if ($iterableAtLeastOnce->yes()) {
 			return $itemType;
 		}

src/Type/StaticType.php

@@ -307,6 +307,16 @@ public function getIterableValueType(): Type
 		return $this->getStaticObjectType()->getIterableValueType();
 	}
 
+	public function getFirstIterableValueType(): Type
+	{
+		return $this->getStaticObjectType()->getFirstIterableValueType();
+	}
+
+	public function getLastIterableValueType(): Type
+	{
+		return $this->getStaticObjectType()->getLastIterableValueType();
+	}
+
 	public function isOffsetAccessible(): TrinaryLogic
 	{
 		return $this->getStaticObjectType()->isOffsetAccessible();

src/Type/Traits/LateResolvableTypeTrait.php

@@ -135,6 +135,16 @@ public function getIterableValueType(): Type
 		return $this->resolve()->getIterableValueType();
 	}
 
+	public function getFirstIterableValueType(): Type
+	{
+		return $this->resolve()->getFirstIterableValueType();
+	}
+
+	public function getLastIterableValueType(): Type
+	{
+		return $this->resolve()->getLastIterableValueType();
+	}
+
 	public function isArray(): TrinaryLogic
 	{
 		return $this->resolve()->isArray();

src/Type/Traits/MaybeArrayTypeTrait.php

@@ -3,6 +3,8 @@
 namespace PHPStan\Type\Traits;
 
 use PHPStan\TrinaryLogic;
+use PHPStan\Type\MixedType;
+use PHPStan\Type\Type;
 
 trait MaybeArrayTypeTrait
 {
@@ -17,6 +19,16 @@ public function getConstantArrays(): array
 		return [];
 	}
 
+	public function getFirstIterableValueType(): Type
+	{
+		return new MixedType();
+	}
+
+	public function getLastIterableValueType(): Type
+	{
+		return new MixedType();
+	}
+
 	public function isArray(): TrinaryLogic
 	{
 		return TrinaryLogic::createMaybe();