Class PHPStan\Type\GeneralizePrecision

Controls how aggressively Type::generalize() widens a type.

Generalization is the process of widening a specific type to a broader one. For example, generalizing ConstantStringType('hello') yields StringType. This is used when PHPStan needs to merge types across loop iterations or branches where tracking precise constant values is impractical.

Three levels of precision:

• lessSpecific: Aggressive generalization — constant values become their general type (e.g. 'hello' → string, array{foo: int} → array<string, int>)
• moreSpecific: Preserves more detail — e.g. non-empty-string stays non-empty-string instead of widening to string
• templateArgument: Used when generalizing template type arguments, preserving template-specific structure

Used as a parameter to Type::generalize():

$type->generalize(GeneralizePrecision::lessSpecific())