loop and till — Counted Iteration

loop(start, limit, step)

Counted loop with automatic iteration variable $:

loop(0, 10, 1) {
    println(`&{$}`);       // prints 0, 1, 2, ..., 9
}

loop(0, 100, 2) {
    println(`&{$}`);       // prints 0, 2, 4, ..., 98
}

• $ is the automatic iteration variable — no manual declaration needed
• start is the initial value
• limit is the exclusive upper bound
• step is the increment per iteration

till(limit, step)

Shorthand when starting from 0:

till(10, 1) {
    println(`&{$}`);       // prints 0, 1, 2, ..., 9
}

Equivalent to loop(0, limit, step).

Using $ in Expressions

int32:sum = 0;
loop(1, 101, 1) {
    sum = (sum + $);   // sum of 1 to 100
}
println(`&{sum}`);          // 5050

Notes

• No trailing semicolon after closing brace
• $ is a reserved symbol — cannot use for other purposes inside loop body
• For complex iteration, use for instead

Variables Declared Before the Loop (v0.19.3)

Variables declared before a loop or till block remain in scope after the loop exits. This is the idiomatic way to accumulate a result:

int32:sum = 0;
loop(0, 5, 1) {
    sum = (sum + $);
}
// sum is accessible here, equals 0+1+2+3+4 = 10
println(`&{sum}`);

Pre-loop variables can also be used as the exit condition carrier:

int32:found = -1;
loop(0, 10, 1) {
    if (arr[$] == target) {
        found = $;
    }
}
// found holds the last matching index, or -1 if none

Related

• for.md — C-style for loops
• while.md — condition-only loops