NeverType-level representation of Never.
export interface Never extends interface Bottom<out T, out E, out RD, out RE, out Ast extends SchemaAST.AST, out Rebuild extends Top, out TypeMakeIn = T, out Iso = T, in out TypeParameters extends ReadonlyArray<Constraint> = readonly [], out TypeMake = TypeMakeIn, out TypeMutability extends Mutability = "readonly", out TypeOptionality extends Optionality = "required", out TypeConstructorDefault extends ConstructorDefault = "no-default", out EncodedMutability extends Mutability = "readonly", out EncodedOptionality extends Optionality = "required">The fully-parameterized base interface for all schemas. Exposes all 14 type
parameters controlling type inference, mutability, optionality, services, and
transformation behavior.
When to use
Use when you are writing advanced generic schema utilities or performing
schema introspection.
Bottom<never, never, never, never, import SchemaASTSchemaAST.class Neverclass Never {
_tag: 'Never';
getParser: () => SchemaParser.Parser;
getExpected: () => string;
annotations: Schema.Annotations.Annotations | undefined;
checks: Checks | undefined;
encoding: Encoding | undefined;
context: Context | undefined;
toString: () => string;
}
AST node representing the never type — no value matches.
Details
Parsing always fails. Useful as a placeholder in unions or as the result
of narrowing that eliminates all options.
Never, Never> {}
/**
* Schema for the `never` type. Always fails validation — no value satisfies it.
*
* @category schemas
* @since 3.10.0
*/
export const const Never: Neverconst Never: {
Rebuild: Rebuild;
Iso: Iso;
ast: Ast;
Type: T;
Encoded: E;
DecodingServices: RD;
EncodingServices: RE;
annotate: (annotations: Annotations.Bottom<never, readonly []>) => Never;
annotateKey: (annotations: Annotations.Key<never>) => Never;
check: (checks_0: SchemaAST.Check<never>, ...checks: Array<SchemaAST.Check<never>>) => Never;
rebuild: (ast: SchemaAST.Never) => Never;
make: (input: never, options?: MakeOptions) => never;
makeOption: (input: never, options?: MakeOptions) => Option_.Option<never>;
makeEffect: (input: never, options?: MakeOptions) => Effect.Effect<never, SchemaError, never>;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
}
Type-level representation of
Never
.
Schema for the never type. Always fails validation — no value satisfies it.
Never: Never = const make: <S extends Constraint>(
ast: S["ast"],
options?: object
) => S
Creates a schema from an AST (Abstract Syntax Tree) node.
Details
This is the fundamental constructor for all schemas in the Effect Schema
library. It takes an AST node and wraps it in a fully-typed schema that
preserves all type information and provides the complete schema API.
The make function is used internally to create all primitive schemas like
String, Number, Boolean, etc., as well as more complex schemas. It's
the bridge between the untyped AST representation and the strongly-typed
schema.
make(import SchemaASTSchemaAST.const never: SchemaAST.Neverconst never: {
_tag: 'Never';
getParser: () => SchemaParser.Parser;
getExpected: () => string;
annotations: Schema.Annotations.Annotations | undefined;
checks: Checks | undefined;
encoding: Encoding | undefined;
context: Context | undefined;
toString: () => string;
}
Provides the singleton
Never
AST instance.
When to use
Use to reuse the canonical bottom-type AST node when constructing,
comparing, or returning ASTs.
never)