Parameters & Arguments

Parameters

[!IMPORTANT] Parameters in µcad are not positional (which means their order is irrelevant)!

Parameters in µcad always have a name which we often call identifier and a type.

// function with two parameters (`one` and `another`)
fn f(one: Integer, another: Length) {
    std::print("{one} {another}");
}

// call function with two parameters in arbitrary order
f(another = 2m, one = 1);

Arguments

Arguments are the values which are given in call. Each argument consists these elements:

• an optional identifier in lower_snake_case
• a value (e.g. 42, 3.1415, "Hello")
• a type (e.g. Integer, Scalar, Length)
• an optional unit that suits the type (e.g. mm for Length, m² for Area)

Parameter can have defaults. Then the notation changes and the type is deduced from the default value.

// function with two parameters (`one`, `another`, and `one_more`)
fn f(one: Integer, another = 2m, one_more: Area) {
    std::print("{one} {another} {one_more}");
}

// call function with two arguments.
// One matches by name another by type and one_more by default.
f(one = 1, 5m²);

There are several ways in which parameters can match arguments.