Loops and decisions

Compute the running balance.

fn main() {
    tx = [5000, -1200, 300]
    mut total = 0
    for amount in tx {
        total = total + amount
    }
    println(total)
}

if

if total < 0 {
    println(0)
} else {
    println(total)
}

elif and else as you expect. Conditions are bool only.

while

mut i = 0
while i < 3 {
    i = i + 1
}

Ranges

for i in 0..3 { }      # 0, 1, 2
for i in 1..=3 { }     # 1, 2, 3

break / continue

for amount in tx {
    if amount == 0 { continue }
    if total + amount < 0 { break }
    total = total + amount
}

This is the loop in the integer_sum bench (Orbit fold, 0.00× C++ at n=1e8: same n, wrapping checksum). Write the obvious loop. Measure with --release before you clever it. See performance.

Next: functions.