case thing of
Cat ->
meow
Bike ->
ride
Sandwich ->
eat
_ ->
Debug.crash "Not yet implemented"
You can use Debug.crash
when you want the program to fail, typically used when you're in the middle of implementing a case
expression. It is not recommended to use Debug.crash
instead of using a Maybe
or Result
type for unexpected inputs, but typically only during the course of development (i.e. you typically wouldn't publish Elm code which uses Debug.crash
).
Debug.crash
takes one String
value, the error message to show when crashing. Note that Elm will also output the name of the module and the line of the crash, and if the crash is in a case
expression, it will indicate the value of the case
.