if expressions take an expression that evaluates to a Bool (the condition), and two other expressions (the consequent and the alternative) that evaluate to the same type. If the condition evaluates to true, then the consequent will be evaluated and returned, otherwise the alternative will be evaluated and returned.

Pikelet> if true then "hello!" else "goodbye!"
"hello!" : String
Pikelet> if false then "hello!" else "goodbye!"
"goodbye!" : String

Pikelet supports case expressions on strings, and numbers:

case value {
    "hello" => "goodbye";
    "goodbye" => "hello";
    value => value; -- matches all strings
}

Note that we don't (yet) check that the series of patterns provided cover all possible cases, leading to the following embarrassing error:

Pikelet> case "hello" { "hi" => "oh dear" }
error: internal compiler error: no patterns matched the given expression

In the future we' plan to fix this, add support for matching on booleans, and also support more complex patterns (eg. for records).