wasi:io

Types

WIT

@since(version = 0.2.0)
interface error {
  /// A resource which represents some error information.
  ///
  /// The only method provided by this resource is `to-debug-string`,
  /// which provides some human-readable information about the error.
  ///
  /// In the `wasi:io` package, this resource is returned through the
  /// `wasi:io/streams/stream-error` type.
  ///
  /// To provide more specific error information, other interfaces may
  /// offer functions to "downcast" this error into more specific types. For example,
  /// errors returned from streams derived from filesystem types can be described using
  /// the filesystem's own error-code type. This is done using the function
  /// `wasi:filesystem/types/filesystem-error-code`, which takes a `borrow<error>`
  /// parameter and returns an `option<wasi:filesystem/types/error-code>`.
  ///
  /// The set of functions which can "downcast" an `error` into a more
  /// concrete type is open.
  @since(version = 0.2.0)
  resource error {
    /// Returns a string that is suitable to assist humans in debugging
    /// this error.
    ///
    /// WARNING: The returned string should not be consumed mechanically!
    /// It may change across platforms, hosts, or other implementation
    /// details. Parsing this string is a major platform-compatibility
    /// hazard.
    @since(version = 0.2.0)
    to-debug-string: func() -> string;
  }
}