API Reference / @evolu/common / Type / TransformType

Interface: TransformType<FromType, ToType, TransformError>

Defined in: packages/common/src/Type.ts:1893

TransformType extends Type with additional fromType and toType properties for reflection.

Extends

• Type<"Transform", InferType<ToType>, InferInput<FromType>, TransformError, InferType<FromType>, InferErrors<FromType>>

Type Parameters

Type Parameter	Default type
FromType extends AnyType	-
ToType extends AnyType	-
TransformError extends TypeError	never

Properties

Property	Modifier	Type	Description	Overrides	Inherited from	Defined in
[EvoluTypeSymbol]	readonly	true	-	-	Type.[EvoluTypeSymbol]	packages/common/src/Type.ts:171
Error	public	TransformError	The specific error introduced by this Type. ### Example type StringError = typeof String.Error;	-	Type.Error	packages/common/src/Type.ts:96
Errors	readonly	| TransformError | InferErrors<FromType>	Error	ParentError ### Example type StringParentErrors = typeof String.Errors;	-	Type.Errors
from	readonly	(value) => Result<InferType<ToType>, | TransformError | InferErrors<FromType>>	Creates T from an Input value. This is useful when we have a typed value. from is a typed alias of fromUnknown.	-	Type.from	packages/common/src/Type.ts:111
fromParent	readonly	(value) => [TransformError] extends [never] ? Ok<InferType<ToType>> : Result<InferType<ToType>, TransformError>	Creates T from Parent type. This function skips parent Types validations/transformations when we have already partially validated/transformed value. For example, TrimString.from checks whether a value is a string and trims it. If we only want to trim a string, we can use fromParent. ### Example // string & Brand<"Trimmed"> const value = TrimString.fromParent("a ").value; // as efficient as foo.trim()	Type.fromParent	-	packages/common/src/Type.ts:1908
fromType	readonly	FromType	-	-	-	packages/common/src/Type.ts:1905
fromUnknown	readonly	(value) => Result<InferType<ToType>, | TransformError | InferErrors<FromType>>	Creates T from an unknown value. This is useful when a value is unknown.	-	Type.fromUnknown	packages/common/src/Type.ts:118
Input	public	InferInput<FromType>	The type expected by from and fromUnknown. ### Example type StringInput = typeof String.Input;	-	Type.Input	packages/common/src/Type.ts:94
is	readonly	(value) => value is InferType<ToType>	A type guard that checks whether an unknown value satisfies the Type. ### Example const value: unknown = "hello"; if (String.is(value)) { // TypeScript now knows valueis astring here. console.log("This is a valid string!"); } const strings: unknown[] = [1, "hello", true, "world"]; const filteredStrings = strings.filter(String.is); console.log(filteredStrings); // ["hello", "world"]	-	Type.is	packages/common/src/Type.ts:169
name	readonly	"Transform"	-	-	Type.name	packages/common/src/Type.ts:102
Parent	public	InferType<FromType>	The parent type. ### Example type StringParent = typeof String.Parent;	-	Type.Parent	packages/common/src/Type.ts:98
ParentError	public	InferErrors<FromType>	The parent's error. ### Example type StringParentError = typeof String.ParentError;	-	Type.ParentError	packages/common/src/Type.ts:100
to	readonly	(value) => InferInput	The opposite of from and fromUnknown. This is useful to transform T back to its Input representation. For refine, it only removes the brand. For transform, it changes value.	-	Type.to	packages/common/src/Type.ts:127
toParent	readonly	(value) => InferType	The opposite of fromParent.	-	Type.toParent	packages/common/src/Type.ts:148
toType	readonly	ToType	-	-	-	packages/common/src/Type.ts:1906
Type	readonly	InferType	The type this Type resolves to. ### Example type String = typeof String.Type;	-	Type.Type	packages/common/src/Type.ts:182