Expressions

An expression is anything that has a value. Like most languages this includes things like integers literals, instantiations and operators. However, unlike the languages you may be used to, almost everything in Spade is an expression and has a value, for example if-expression and match-blocks.

This means, among other things, that you can assign the ‘result’ of an if-expression to a variable:

letlet is used to define a variable. Spade infers the type of most variables from context, but you can also specifReturns the value of the first branch if the condition is true, otherwise the second branch.
Note that unlike software languages, Spade does not have conditional execution. You do not conditionally assign values inside if expressiosn, you compute a value and return it.y the type with : <type> before the =. a = ifReturns the value of the first branch if the condition is true, otherwise the second branch.
Note that unlike software languages, Spade does not have conditional execution. You do not conditionally assign values inside if expressiosn, you compute a value and return it. choose_b {
    b
}
else {
    c
};