File src/Type/GeneralizePrecision.php

1:	<?php declare(strict_types = 1);
2:
3:	namespace PHPStan\Type;
4:
5:	/**
6:	* Controls how aggressively Type::generalize() widens a type.
7:	*
8:	* Generalization is the process of widening a specific type to a broader one.
9:	* For example, generalizing ConstantStringType('hello') yields StringType.
10:	* This is used when PHPStan needs to merge types across loop iterations or
11:	* branches where tracking precise constant values is impractical.
12:	*
13:	* Three levels of precision:
14:	* - lessSpecific: Aggressive generalization — constant values become their
15:	* general type (e.g. 'hello' → string, array{foo: int} → array<string, int>)
16:	* - moreSpecific: Preserves more detail — e.g. non-empty-string stays
17:	* non-empty-string instead of widening to string
18:	* - templateArgument: Used when generalizing template type arguments,
19:	* preserving template-specific structure
20:	*
21:	* Used as a parameter to Type::generalize():
22:	*
23:	* $type->generalize(GeneralizePrecision::lessSpecific())
24:	*/
25:	final class GeneralizePrecision
26:	{
27:
28:	private const LESS_SPECIFIC = 1;
29:	private const MORE_SPECIFIC = 2;
30:	private const TEMPLATE_ARGUMENT = 3;
31:
32:	/** @var self[] */
33:	private static array $registry;
34:
35:	private function __construct(private int $value)
36:	{
37:	}
38:
39:	private static function create(int $value): self
40:	{
41:	self::$registry[$value] ??= new self($value);
42:	return self::$registry[$value];
43:	}
44:
45:	/** @api */
46:	public static function lessSpecific(): self
47:	{
48:	return self::create(self::LESS_SPECIFIC);
49:	}
50:
51:	/** @api */
52:	public static function moreSpecific(): self
53:	{
54:	return self::create(self::MORE_SPECIFIC);
55:	}
56:
57:	/** @api */
58:	public static function templateArgument(): self
59:	{
60:	return self::create(self::TEMPLATE_ARGUMENT);
61:	}
62:
63:	public function isMoreSpecific(): bool
64:	{
65:	return $this->value === self::MORE_SPECIFIC;
66:	}
67:
68:	public function isTemplateArgument(): bool
69:	{
70:	return $this->value === self::TEMPLATE_ARGUMENT;
71:	}
72:
73:	}
74:

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