result

Error handling with Result types.

use result

Arc uses Result<T> as the standard error-handling pattern — either Ok(value) or Err(message).

Functions

Function	Signature	Description
ok	(value) -> Result<T>	Wrap value in Ok
err	(msg) -> Result<T>	Create an Err
is_ok	(r) -> Bool	Check if Ok
is_err	(r) -> Bool	Check if Err
unwrap	(r) -> T	Get value or panic
unwrap_or	(r, default) -> T	Get value or default
unwrap_err	(r) -> String	Get error message or panic
map	(r, fn) -> Result<U>	Transform Ok value
flat_map	(r, fn) -> Result<U>	Chain Result-returning functions
try_fn	(fn) -> Result<T>	Run function, catching errors as Err
result_is_ok	(r) -> Bool	Check if Ok (alternate form)
result_is_err	(r) -> Bool	Check if Err (alternate form)
result_unwrap	(r) -> T	Unwrap (alternate form)
result_unwrap_or	(r, default) -> T	Unwrap or default (alternate form)
result_map	(r, fn) -> Result<U>	Map Ok value (alternate form)
flat_map_result	(r, fn) -> Result<U>	Chain Results (alternate form)

Example

use result

let r = result.ok(42)
let doubled = r |> result.map(x => x * 2)  # Ok(84)

let e = result.err("not found")
result.unwrap_or(e, 0)  # => 0