1: | <?php declare(strict_types = 1); |
2: | |
3: | namespace PHPStan\Type\Generic; |
4: | |
5: | use PHPStan\PhpDocParser\Ast\Type\GenericTypeNode; |
6: | use PHPStan\ShouldNotHappenException; |
7: | use PHPStan\TrinaryLogic; |
8: | use PHPStan\Type\BenevolentUnionType; |
9: | use PHPStan\Type\IsSuperTypeOfResult; |
10: | use PHPStan\Type\MixedType; |
11: | use PHPStan\Type\NeverType; |
12: | use PHPStan\Type\Type; |
13: | use function sprintf; |
14: | |
15: | |
16: | |
17: | |
18: | final class TemplateTypeVariance |
19: | { |
20: | |
21: | private const INVARIANT = 1; |
22: | private const COVARIANT = 2; |
23: | private const CONTRAVARIANT = 3; |
24: | private const STATIC = 4; |
25: | private const BIVARIANT = 5; |
26: | |
27: | |
28: | private static array $registry; |
29: | |
30: | private function __construct(private int $value) |
31: | { |
32: | } |
33: | |
34: | private static function create(int $value): self |
35: | { |
36: | self::$registry[$value] ??= new self($value); |
37: | return self::$registry[$value]; |
38: | } |
39: | |
40: | public static function createInvariant(): self |
41: | { |
42: | return self::create(self::INVARIANT); |
43: | } |
44: | |
45: | public static function createCovariant(): self |
46: | { |
47: | return self::create(self::COVARIANT); |
48: | } |
49: | |
50: | public static function createContravariant(): self |
51: | { |
52: | return self::create(self::CONTRAVARIANT); |
53: | } |
54: | |
55: | public static function createStatic(): self |
56: | { |
57: | return self::create(self::STATIC); |
58: | } |
59: | |
60: | public static function createBivariant(): self |
61: | { |
62: | return self::create(self::BIVARIANT); |
63: | } |
64: | |
65: | public function invariant(): bool |
66: | { |
67: | return $this->value === self::INVARIANT; |
68: | } |
69: | |
70: | public function covariant(): bool |
71: | { |
72: | return $this->value === self::COVARIANT; |
73: | } |
74: | |
75: | public function contravariant(): bool |
76: | { |
77: | return $this->value === self::CONTRAVARIANT; |
78: | } |
79: | |
80: | public function static(): bool |
81: | { |
82: | return $this->value === self::STATIC; |
83: | } |
84: | |
85: | public function bivariant(): bool |
86: | { |
87: | return $this->value === self::BIVARIANT; |
88: | } |
89: | |
90: | public function compose(self $other): self |
91: | { |
92: | if ($this->contravariant()) { |
93: | if ($other->contravariant()) { |
94: | return self::createCovariant(); |
95: | } |
96: | if ($other->covariant()) { |
97: | return self::createContravariant(); |
98: | } |
99: | if ($other->bivariant()) { |
100: | return self::createBivariant(); |
101: | } |
102: | return self::createInvariant(); |
103: | } |
104: | |
105: | if ($this->covariant()) { |
106: | if ($other->contravariant()) { |
107: | return self::createContravariant(); |
108: | } |
109: | if ($other->covariant()) { |
110: | return self::createCovariant(); |
111: | } |
112: | if ($other->bivariant()) { |
113: | return self::createBivariant(); |
114: | } |
115: | return self::createInvariant(); |
116: | } |
117: | |
118: | if ($this->invariant()) { |
119: | return self::createInvariant(); |
120: | } |
121: | |
122: | if ($this->bivariant()) { |
123: | return self::createBivariant(); |
124: | } |
125: | |
126: | return $other; |
127: | } |
128: | |
129: | public function isValidVariance(TemplateType $templateType, Type $a, Type $b): IsSuperTypeOfResult |
130: | { |
131: | if ($b instanceof NeverType) { |
132: | return IsSuperTypeOfResult::createYes(); |
133: | } |
134: | |
135: | if ($a instanceof MixedType && !$a instanceof TemplateType) { |
136: | return IsSuperTypeOfResult::createYes(); |
137: | } |
138: | |
139: | if ($a instanceof BenevolentUnionType) { |
140: | if (!$a->isSuperTypeOf($b)->no()) { |
141: | return IsSuperTypeOfResult::createYes(); |
142: | } |
143: | } |
144: | |
145: | if ($b instanceof BenevolentUnionType) { |
146: | if (!$b->isSuperTypeOf($a)->no()) { |
147: | return IsSuperTypeOfResult::createYes(); |
148: | } |
149: | } |
150: | |
151: | if ($b instanceof MixedType && !$b instanceof TemplateType) { |
152: | return IsSuperTypeOfResult::createYes(); |
153: | } |
154: | |
155: | if ($this->invariant()) { |
156: | $result = $a->equals($b); |
157: | $reasons = []; |
158: | if (!$result) { |
159: | if ( |
160: | $templateType->getScope()->getClassName() !== null |
161: | && $a->isSuperTypeOf($b)->yes() |
162: | ) { |
163: | $reasons[] = sprintf( |
164: | 'Template type %s on class %s is not covariant. Learn more: <fg=cyan>https://phpstan.org/blog/whats-up-with-template-covariant</>', |
165: | $templateType->getName(), |
166: | $templateType->getScope()->getClassName(), |
167: | ); |
168: | } |
169: | } |
170: | |
171: | return new IsSuperTypeOfResult(TrinaryLogic::createFromBoolean($result), $reasons); |
172: | } |
173: | |
174: | if ($this->covariant()) { |
175: | return $a->isSuperTypeOf($b); |
176: | } |
177: | |
178: | if ($this->contravariant()) { |
179: | return $b->isSuperTypeOf($a); |
180: | } |
181: | |
182: | if ($this->bivariant()) { |
183: | return IsSuperTypeOfResult::createYes(); |
184: | } |
185: | |
186: | throw new ShouldNotHappenException(); |
187: | } |
188: | |
189: | public function equals(self $other): bool |
190: | { |
191: | return $other->value === $this->value; |
192: | } |
193: | |
194: | public function validPosition(self $other): bool |
195: | { |
196: | return $other->value === $this->value |
197: | || $other->invariant() |
198: | || $this->bivariant() |
199: | || $this->static(); |
200: | } |
201: | |
202: | public function describe(): string |
203: | { |
204: | switch ($this->value) { |
205: | case self::INVARIANT: |
206: | return 'invariant'; |
207: | case self::COVARIANT: |
208: | return 'covariant'; |
209: | case self::CONTRAVARIANT: |
210: | return 'contravariant'; |
211: | case self::STATIC: |
212: | return 'static'; |
213: | case self::BIVARIANT: |
214: | return 'bivariant'; |
215: | } |
216: | |
217: | throw new ShouldNotHappenException(); |
218: | } |
219: | |
220: | |
221: | |
222: | |
223: | public function toPhpDocNodeVariance(): string |
224: | { |
225: | switch ($this->value) { |
226: | case self::INVARIANT: |
227: | return GenericTypeNode::VARIANCE_INVARIANT; |
228: | case self::COVARIANT: |
229: | return GenericTypeNode::VARIANCE_COVARIANT; |
230: | case self::CONTRAVARIANT: |
231: | return GenericTypeNode::VARIANCE_CONTRAVARIANT; |
232: | case self::BIVARIANT: |
233: | return GenericTypeNode::VARIANCE_BIVARIANT; |
234: | } |
235: | |
236: | throw new ShouldNotHappenException(); |
237: | } |
238: | |
239: | } |
240: | |