Case expressions

The case expression is the most common kind of flow control in Gleam code. It is similar to switch in some other languages, but more powerful than most.

It allows the programmer to say "if the data has this shape then run this code", a process called pattern matching.

Gleam performs exhaustiveness checking to ensure that the patterns in a case expression cover all possible values. With this you can have confidence that your logic is up-to-date for the design of the data you are working with.

Try commenting out patterns or adding new redundant ones, and see what problems the compiler reports.