26: Compile‐time Loops - royal-lang/rl GitHub Wiki

Just like Royal has compile-time conditionals and it also supports compile-time loops.

All type of loops like for,foreach and while have static versions.

A static loop can be executed anywhere and not just in code and can be used to dynamically create multiple variables etc.

Static loops do not create scopes BUT any compile-time constants like enum created within their scope will be unique per iteration and thus there is a compile-time scope.

static for (PRE_INITIALIZATION, CONDITION, POST_EXPRESSION) // Or just: static for PRE_INITIALIZATION, CONDITION, POST_EXPRESSION
{
    ...
}

static foreach (VALUE, ITERATABLE_ELEMENTS) // ITERATABLE_ELEMENTS are ex. arrays, ranges etc. Or just: foreach VALUE, ITERATABLE_ELEMENTS
{
    ...
}

static foreach (INDEX, FROM .. TO) // FROM and TO must be integers.
{
    ...
}

static foreach (KEY,VALUE, ITERABLE_ELEMENTS) // ITERABLE_ELEMENTS are ex. arrays, associative arrays etc.
{
    ...
}

static while (CONDITION) // Or just: static while CONDITION
{
    ...
}

static do
{
    ...
} static while (CONDITION);

Examples:

enum names = ["x", "y", "z"];

struct Point3d
{
    static foreach (name, names)
    {
        enum varName = "var int " ~ name ~ ";";

        mixin(varName);
    }
}

Result:

struct Point3d
{
    var int x;
    var int y;
    var int z;
}