Function when

when<T>(value: unknown, guard: (v: unknown) => v is T): T | undefined
Conditionally coalesces a value based on a predicate guard. Returns the value (narrowed by the guard) if the guard returns true, otherwise returns the fallback.
Type Parameters
- T
Parameters
- value: unknown
  The candidate value to test
- guard: (v: unknown) => v is T
  A predicate or type guard function
Returns T | undefined
The value or fallback
Example
```
when('hello', isString);              // 'hello'
when(123, isString);                  // undefined
when(123, isString, 'default');       // 'default'
when(rawIso, v => v !== 'INVALID');   // rawIso or undefined
```
- Defined in packages/library/src/common/primitives/coercion.library.ts:92
when<T>(
    value: unknown,
    guard: (v: unknown) => v is T,
    fallback: undefined,
): T | undefined
Conditionally coalesces a value based on a predicate guard. Returns the value (narrowed by the guard) if the guard returns true, otherwise returns the fallback.
Type Parameters
- T
Parameters
- value: unknown
  The candidate value to test
- guard: (v: unknown) => v is T
  A predicate or type guard function
- fallback: undefined
  Optional fallback value if the guard returns false
Returns T | undefined
The value or fallback
Example
```
when('hello', isString);              // 'hello'
when(123, isString);                  // undefined
when(123, isString, 'default');       // 'default'
when(rawIso, v => v !== 'INVALID');   // rawIso or undefined
```
- Defined in packages/library/src/common/primitives/coercion.library.ts:93
when<T, U>(value: unknown, guard: (v: unknown) => v is T, fallback: U): T | U
Conditionally coalesces a value based on a predicate guard. Returns the value (narrowed by the guard) if the guard returns true, otherwise returns the fallback.
Type Parameters
- T
- U
Parameters
- value: unknown
  The candidate value to test
- guard: (v: unknown) => v is T
  A predicate or type guard function
- fallback: U
  Optional fallback value if the guard returns false
Returns T | U
The value or fallback
Example
```
when('hello', isString);              // 'hello'
when(123, isString);                  // undefined
when(123, isString, 'default');       // 'default'
when(rawIso, v => v !== 'INVALID');   // rawIso or undefined
```
- Defined in packages/library/src/common/primitives/coercion.library.ts:94
when<T>(value: T, guard: (v: T) => boolean): T | undefined
Conditionally coalesces a value based on a predicate guard. Returns the value (narrowed by the guard) if the guard returns true, otherwise returns the fallback.
Type Parameters
- T
Parameters
- value: T
  The candidate value to test
- guard: (v: T) => boolean
  A predicate or type guard function
Returns T | undefined
The value or fallback
Example
```
when('hello', isString);              // 'hello'
when(123, isString);                  // undefined
when(123, isString, 'default');       // 'default'
when(rawIso, v => v !== 'INVALID');   // rawIso or undefined
```
- Defined in packages/library/src/common/primitives/coercion.library.ts:95
when<T, U>(value: T, guard: (v: T) => boolean, fallback: U): T | U
Conditionally coalesces a value based on a predicate guard. Returns the value (narrowed by the guard) if the guard returns true, otherwise returns the fallback.
Type Parameters
- T
- U
Parameters
- value: T
  The candidate value to test
- guard: (v: T) => boolean
  A predicate or type guard function
- fallback: U
  Optional fallback value if the guard returns false
Returns T | U
The value or fallback
Example
```
when('hello', isString);              // 'hello'
when(123, isString);                  // undefined
when(123, isString, 'default');       // 'default'
when(rawIso, v => v !== 'INVALID');   // rawIso or undefined
```
- Defined in packages/library/src/common/primitives/coercion.library.ts:96

Function when

Type Parameters

Parameters

Returns T | undefined

Example

Type Parameters

Parameters

Returns T | undefined

Example

Type Parameters

Parameters

Returns T | U

Example

Type Parameters

Parameters

Returns T | undefined

Example

Type Parameters

Parameters

Returns T | U

Example

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