type t;
let valueMissing: t => bool;let typeMismatch: t => bool;let patternMismatch: t => bool;let tooLong: t => bool;let tooShort: t => bool;let rangeUnderflow: t => bool;let rangeOverflow: t => bool;let stepMismatch: t => bool;let badInput: t => bool;let customError: t => bool;let valid: t => bool;