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.
type error = error;