| 1: | <?php declare(strict_types = 1); |
| 2: | |
| 3: | namespace PHPStan\Type\Generic; |
| 4: | |
| 5: | use PHPStan\ShouldNotHappenException; |
| 6: | use PHPStan\TrinaryLogic; |
| 7: | use PHPStan\Type\BenevolentUnionType; |
| 8: | use PHPStan\Type\MixedType; |
| 9: | use PHPStan\Type\NeverType; |
| 10: | use PHPStan\Type\Type; |
| 11: | |
| 12: | |
| 13: | class TemplateTypeVariance |
| 14: | { |
| 15: | |
| 16: | private const INVARIANT = 1; |
| 17: | private const COVARIANT = 2; |
| 18: | private const CONTRAVARIANT = 3; |
| 19: | private const STATIC = 4; |
| 20: | |
| 21: | |
| 22: | private static array $registry; |
| 23: | |
| 24: | private static bool $invarianceCompositionEnabled = false; |
| 25: | |
| 26: | private function __construct(private int $value) |
| 27: | { |
| 28: | } |
| 29: | |
| 30: | private static function create(int $value): self |
| 31: | { |
| 32: | self::$registry[$value] ??= new self($value); |
| 33: | return self::$registry[$value]; |
| 34: | } |
| 35: | |
| 36: | public static function createInvariant(): self |
| 37: | { |
| 38: | return self::create(self::INVARIANT); |
| 39: | } |
| 40: | |
| 41: | public static function createCovariant(): self |
| 42: | { |
| 43: | return self::create(self::COVARIANT); |
| 44: | } |
| 45: | |
| 46: | public static function createContravariant(): self |
| 47: | { |
| 48: | return self::create(self::CONTRAVARIANT); |
| 49: | } |
| 50: | |
| 51: | public static function createStatic(): self |
| 52: | { |
| 53: | return self::create(self::STATIC); |
| 54: | } |
| 55: | |
| 56: | public function invariant(): bool |
| 57: | { |
| 58: | return $this->value === self::INVARIANT; |
| 59: | } |
| 60: | |
| 61: | public function covariant(): bool |
| 62: | { |
| 63: | return $this->value === self::COVARIANT; |
| 64: | } |
| 65: | |
| 66: | public function contravariant(): bool |
| 67: | { |
| 68: | return $this->value === self::CONTRAVARIANT; |
| 69: | } |
| 70: | |
| 71: | public function static(): bool |
| 72: | { |
| 73: | return $this->value === self::STATIC; |
| 74: | } |
| 75: | |
| 76: | public function compose(self $other): self |
| 77: | { |
| 78: | if ($this->contravariant()) { |
| 79: | if ($other->contravariant()) { |
| 80: | return self::createCovariant(); |
| 81: | } |
| 82: | if ($other->covariant()) { |
| 83: | return self::createContravariant(); |
| 84: | } |
| 85: | return self::createInvariant(); |
| 86: | } |
| 87: | |
| 88: | if ($this->covariant()) { |
| 89: | if ($other->contravariant()) { |
| 90: | return self::createContravariant(); |
| 91: | } |
| 92: | if ($other->covariant()) { |
| 93: | return self::createCovariant(); |
| 94: | } |
| 95: | return self::createInvariant(); |
| 96: | } |
| 97: | |
| 98: | if (self::$invarianceCompositionEnabled && $this->invariant()) { |
| 99: | return self::createInvariant(); |
| 100: | } |
| 101: | |
| 102: | return $other; |
| 103: | } |
| 104: | |
| 105: | public function isValidVariance(Type $a, Type $b): TrinaryLogic |
| 106: | { |
| 107: | if ($b instanceof NeverType) { |
| 108: | return TrinaryLogic::createYes(); |
| 109: | } |
| 110: | |
| 111: | if ($a instanceof MixedType && !$a instanceof TemplateType) { |
| 112: | return TrinaryLogic::createYes(); |
| 113: | } |
| 114: | |
| 115: | if ($a instanceof BenevolentUnionType) { |
| 116: | if (!$a->isSuperTypeOf($b)->no()) { |
| 117: | return TrinaryLogic::createYes(); |
| 118: | } |
| 119: | } |
| 120: | |
| 121: | if ($b instanceof BenevolentUnionType) { |
| 122: | if (!$b->isSuperTypeOf($a)->no()) { |
| 123: | return TrinaryLogic::createYes(); |
| 124: | } |
| 125: | } |
| 126: | |
| 127: | if ($b instanceof MixedType && !$b instanceof TemplateType) { |
| 128: | return TrinaryLogic::createYes(); |
| 129: | } |
| 130: | |
| 131: | if ($this->invariant()) { |
| 132: | return TrinaryLogic::createFromBoolean($a->equals($b)); |
| 133: | } |
| 134: | |
| 135: | if ($this->covariant()) { |
| 136: | return $a->isSuperTypeOf($b); |
| 137: | } |
| 138: | |
| 139: | if ($this->contravariant()) { |
| 140: | return $b->isSuperTypeOf($a); |
| 141: | } |
| 142: | |
| 143: | throw new ShouldNotHappenException(); |
| 144: | } |
| 145: | |
| 146: | public function equals(self $other): bool |
| 147: | { |
| 148: | return $other->value === $this->value; |
| 149: | } |
| 150: | |
| 151: | public function validPosition(self $other): bool |
| 152: | { |
| 153: | return $other->value === $this->value |
| 154: | || $other->invariant() |
| 155: | || $this->static(); |
| 156: | } |
| 157: | |
| 158: | public function describe(): string |
| 159: | { |
| 160: | switch ($this->value) { |
| 161: | case self::INVARIANT: |
| 162: | return 'invariant'; |
| 163: | case self::COVARIANT: |
| 164: | return 'covariant'; |
| 165: | case self::CONTRAVARIANT: |
| 166: | return 'contravariant'; |
| 167: | case self::STATIC: |
| 168: | return 'static'; |
| 169: | } |
| 170: | |
| 171: | throw new ShouldNotHappenException(); |
| 172: | } |
| 173: | |
| 174: | |
| 175: | |
| 176: | |
| 177: | public static function __set_state(array $properties): self |
| 178: | { |
| 179: | return new self($properties['value']); |
| 180: | } |
| 181: | |
| 182: | public static function setInvarianceCompositionEnabled(bool $enabled): void |
| 183: | { |
| 184: | self::$invarianceCompositionEnabled = $enabled; |
| 185: | } |
| 186: | |
| 187: | } |
| 188: | |