| 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\AcceptsResult; |
| 8: | use PHPStan\Type\BenevolentUnionType; |
| 9: | use PHPStan\Type\MixedType; |
| 10: | use PHPStan\Type\NeverType; |
| 11: | use PHPStan\Type\Type; |
| 12: | use function sprintf; |
| 13: | |
| 14: | |
| 15: | class TemplateTypeVariance |
| 16: | { |
| 17: | |
| 18: | private const INVARIANT = 1; |
| 19: | private const COVARIANT = 2; |
| 20: | private const CONTRAVARIANT = 3; |
| 21: | private const STATIC = 4; |
| 22: | |
| 23: | |
| 24: | private static array $registry; |
| 25: | |
| 26: | private static bool $invarianceCompositionEnabled = false; |
| 27: | |
| 28: | private function __construct(private int $value) |
| 29: | { |
| 30: | } |
| 31: | |
| 32: | private static function create(int $value): self |
| 33: | { |
| 34: | self::$registry[$value] ??= new self($value); |
| 35: | return self::$registry[$value]; |
| 36: | } |
| 37: | |
| 38: | public static function createInvariant(): self |
| 39: | { |
| 40: | return self::create(self::INVARIANT); |
| 41: | } |
| 42: | |
| 43: | public static function createCovariant(): self |
| 44: | { |
| 45: | return self::create(self::COVARIANT); |
| 46: | } |
| 47: | |
| 48: | public static function createContravariant(): self |
| 49: | { |
| 50: | return self::create(self::CONTRAVARIANT); |
| 51: | } |
| 52: | |
| 53: | public static function createStatic(): self |
| 54: | { |
| 55: | return self::create(self::STATIC); |
| 56: | } |
| 57: | |
| 58: | public function invariant(): bool |
| 59: | { |
| 60: | return $this->value === self::INVARIANT; |
| 61: | } |
| 62: | |
| 63: | public function covariant(): bool |
| 64: | { |
| 65: | return $this->value === self::COVARIANT; |
| 66: | } |
| 67: | |
| 68: | public function contravariant(): bool |
| 69: | { |
| 70: | return $this->value === self::CONTRAVARIANT; |
| 71: | } |
| 72: | |
| 73: | public function static(): bool |
| 74: | { |
| 75: | return $this->value === self::STATIC; |
| 76: | } |
| 77: | |
| 78: | public function compose(self $other): self |
| 79: | { |
| 80: | if ($this->contravariant()) { |
| 81: | if ($other->contravariant()) { |
| 82: | return self::createCovariant(); |
| 83: | } |
| 84: | if ($other->covariant()) { |
| 85: | return self::createContravariant(); |
| 86: | } |
| 87: | return self::createInvariant(); |
| 88: | } |
| 89: | |
| 90: | if ($this->covariant()) { |
| 91: | if ($other->contravariant()) { |
| 92: | return self::createContravariant(); |
| 93: | } |
| 94: | if ($other->covariant()) { |
| 95: | return self::createCovariant(); |
| 96: | } |
| 97: | return self::createInvariant(); |
| 98: | } |
| 99: | |
| 100: | if (self::$invarianceCompositionEnabled && $this->invariant()) { |
| 101: | return self::createInvariant(); |
| 102: | } |
| 103: | |
| 104: | return $other; |
| 105: | } |
| 106: | |
| 107: | public function isValidVariance(Type $a, Type $b): TrinaryLogic |
| 108: | { |
| 109: | return $this->isValidVarianceWithReason(null, $a, $b)->result; |
| 110: | } |
| 111: | |
| 112: | public function isValidVarianceWithReason(?TemplateType $templateType, Type $a, Type $b): AcceptsResult |
| 113: | { |
| 114: | if ($b instanceof NeverType) { |
| 115: | return AcceptsResult::createYes(); |
| 116: | } |
| 117: | |
| 118: | if ($a instanceof MixedType && !$a instanceof TemplateType) { |
| 119: | return AcceptsResult::createYes(); |
| 120: | } |
| 121: | |
| 122: | if ($a instanceof BenevolentUnionType) { |
| 123: | if (!$a->isSuperTypeOf($b)->no()) { |
| 124: | return AcceptsResult::createYes(); |
| 125: | } |
| 126: | } |
| 127: | |
| 128: | if ($b instanceof BenevolentUnionType) { |
| 129: | if (!$b->isSuperTypeOf($a)->no()) { |
| 130: | return AcceptsResult::createYes(); |
| 131: | } |
| 132: | } |
| 133: | |
| 134: | if ($b instanceof MixedType && !$b instanceof TemplateType) { |
| 135: | return AcceptsResult::createYes(); |
| 136: | } |
| 137: | |
| 138: | if ($this->invariant()) { |
| 139: | $result = $a->equals($b); |
| 140: | $reasons = []; |
| 141: | if (!$result) { |
| 142: | if ( |
| 143: | $templateType !== null |
| 144: | && $templateType->getScope()->getClassName() !== null |
| 145: | && $a->isSuperTypeOf($b)->yes() |
| 146: | ) { |
| 147: | $reasons[] = sprintf( |
| 148: | 'Template type %s on class %s is not covariant. Learn more: <fg=cyan>https://phpstan.org/blog/whats-up-with-template-covariant</>', |
| 149: | $templateType->getName(), |
| 150: | $templateType->getScope()->getClassName(), |
| 151: | ); |
| 152: | } |
| 153: | } |
| 154: | |
| 155: | return new AcceptsResult(TrinaryLogic::createFromBoolean($result), $reasons); |
| 156: | } |
| 157: | |
| 158: | if ($this->covariant()) { |
| 159: | return new AcceptsResult($a->isSuperTypeOf($b), []); |
| 160: | } |
| 161: | |
| 162: | if ($this->contravariant()) { |
| 163: | return new AcceptsResult($b->isSuperTypeOf($a), []); |
| 164: | } |
| 165: | |
| 166: | throw new ShouldNotHappenException(); |
| 167: | } |
| 168: | |
| 169: | public function equals(self $other): bool |
| 170: | { |
| 171: | return $other->value === $this->value; |
| 172: | } |
| 173: | |
| 174: | public function validPosition(self $other): bool |
| 175: | { |
| 176: | return $other->value === $this->value |
| 177: | || $other->invariant() |
| 178: | || $this->static(); |
| 179: | } |
| 180: | |
| 181: | public function describe(): string |
| 182: | { |
| 183: | switch ($this->value) { |
| 184: | case self::INVARIANT: |
| 185: | return 'invariant'; |
| 186: | case self::COVARIANT: |
| 187: | return 'covariant'; |
| 188: | case self::CONTRAVARIANT: |
| 189: | return 'contravariant'; |
| 190: | case self::STATIC: |
| 191: | return 'static'; |
| 192: | } |
| 193: | |
| 194: | throw new ShouldNotHappenException(); |
| 195: | } |
| 196: | |
| 197: | |
| 198: | |
| 199: | |
| 200: | public static function __set_state(array $properties): self |
| 201: | { |
| 202: | return new self($properties['value']); |
| 203: | } |
| 204: | |
| 205: | public static function setInvarianceCompositionEnabled(bool $enabled): void |
| 206: | { |
| 207: | self::$invarianceCompositionEnabled = $enabled; |
| 208: | } |
| 209: | |
| 210: | } |
| 211: | |