Function partial

packages/effect/src/SchemaAST.ts:2500–2537

(ast: AST, options?: { readonly exact: true })

 * @since 3.10.0
 */
export const partial = (ast: AST, options?: { readonly exact: true }): AST => {
  const exact = options?.exact === true
  switch (ast._tag) {
    case "TupleType":
      return new TupleType(
        ast.elements.map((e) => new OptionalType(exact ? e.type : orUndefined(e.type), true)),
        Arr.match(ast.rest, {
          onEmpty: () => ast.rest,
          onNonEmpty: (rest) => [new Type(Union.make([...getRestASTs(rest), undefinedKeyword]))]
        }),
        ast.isReadonly
      )
    case "TypeLiteral":
      return new TypeLiteral(
        ast.propertySignatures.map((ps) =>
          new PropertySignature(ps.name, exact ? ps.type : orUndefined(ps.type), true, ps.isReadonly, ps.annotations)
        ),
        ast.indexSignatures.map((is) => new IndexSignature(is.parameter, orUndefined(is.type), is.isReadonly))
      )
    case "Union":
      return Union.make(ast.types.map((member) => partial(member, options)))
    case "Suspend":
      return new Suspend(() => partial(ast.f(), options))
    case "Declaration":
    case "Refinement":
      throw new Error(errors_.getASTUnsupportedSchemaErrorMessage(ast))
    case "Transformation": {
      if (
        isTypeLiteralTransformation(ast.transformation) &&
        ast.transformation.propertySignatureTransformations.every(isRenamingPropertySignatureTransformation)
      ) {
        return new Transformation(partial(ast.from, options), partial(ast.to, options), ast.transformation)
      }
      throw new Error(errors_.getASTUnsupportedSchemaErrorMessage(ast))
    }
  }
  return ast
}

/**
 * Equivalent at runtime to the built-in TypeScript utility type `Required`.