Added literal type (#1731)

Author: norberttech

src/lib/types/src/Flow/Types/DSL/functions.php

@@ -12,6 +12,7 @@
     InstanceOfType,
     JsonType,
     ListType,
+    LiteralType,
     MapType,
     NonEmptyStringType,
     NumericStringType,
@@ -338,6 +339,19 @@ function type_enum(string $class) : EnumType
     return new EnumType($class);
 }
 
+/**
+ * @template T of bool|float|int|string
+ *
+ * @param T $value
+ *
+ * @return LiteralType<T>
+ */
+#[DocumentationDSL(module: Module::TYPES, type: DSLType::TYPE)]
+function type_literal(bool|float|int|string $value) : LiteralType
+{
+    return new LiteralType($value);
+}
+
 /**
  * @template T
  *

src/lib/types/src/Flow/Types/Type/Logical/LiteralType.php

@@ -0,0 +1,68 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Flow\Types\Type\Logical;
+
+use Flow\Types\Exception\{CastingException, InvalidTypeException};
+use Flow\Types\Type;
+
+/**
+ * @template T of bool|float|int|string
+ *
+ * @implements Type<T>
+ */
+final readonly class LiteralType implements Type
+{
+    /**
+     * @param T $value
+     */
+    public function __construct(
+        private bool|float|int|string $value,
+    ) {
+    }
+
+    public function assert(mixed $value) : bool|float|int|string
+    {
+        if ($this->isValid($value)) {
+            return $value;
+        }
+
+        throw InvalidTypeException::value($value, $this);
+    }
+
+    public function cast(mixed $value) : bool|float|int|string
+    {
+        if ($this->isValid($value)) {
+            return $value;
+        }
+
+        throw new CastingException($value, $this);
+    }
+
+    public function isValid(mixed $value) : bool
+    {
+        return $value === $this->value;
+    }
+
+    public function normalize() : array
+    {
+        return [
+            'type' => 'literal',
+            'value' => (string) $this->value,
+        ];
+    }
+
+    public function toString() : string
+    {
+        if (\is_string($this->value)) {
+            return "'{$this->value}'";
+        }
+
+        if (\is_bool($this->value)) {
+            return $this->value ? 'true' : 'false';
+        }
+
+        return (string) $this->value;
+    }
+}

src/lib/types/src/Flow/Types/Type/TypeFactory.php

@@ -12,6 +12,7 @@
     type_float,
     type_integer,
     type_json,
+    type_literal,
     type_mixed,
     type_non_empty_string,
     type_null,
@@ -64,6 +65,7 @@ public static function fromArray(array $data) : Type
             'datetime' => type_datetime(),
             'json' => type_json(),
             'uuid' => type_uuid(),
+            'literal' => self::createLiteralFromString($data['value']),
             /** @phpstan-ignore argument.type */
             'list' => ListType::fromArray($data),
             /** @phpstan-ignore argument.type */
@@ -100,4 +102,28 @@ public static function fromString(string $name) : Type
             default => self::fromArray(['type' => $name]),
         };
     }
+
+    /**
+     * @return Type<mixed>
+     */
+    private static function createLiteralFromString(string $value) : Type
+    {
+        if ($value === 'true') {
+            return type_literal(true);
+        }
+
+        if ($value === 'false') {
+            return type_literal(false);
+        }
+
+        if (\is_numeric($value)) {
+            if (\str_contains($value, '.')) {
+                return type_literal((float) $value);
+            }
+
+            return type_literal((int) $value);
+        }
+
+        return type_literal($value);
+    }
 }