Control Flow

Kelvra currently supports if, else, while, classic for, foreach loops, break, continue, and labeled loops.

`if` and `else`

var score i32 = 7

if (score > 5) {
  print("pass")
} else {
  print("retry")
}

Conditions are expressions, not statement-only forms.

var i i32 = 0
while (i < 3) {
  print(i)
  i += 1
}

Semicolons only appear inside for (...) clauses.

for (var i i32 = 0; i < 3; i += 1) {
  print(i)
}

Outside for (...), semicolons are a syntax error.

Foreach uses : instead of semicolons.

var nums Array<i32> = [1, 2, 3]
for (var n i32 : nums) {
  print(n)
}

For dictionaries, iterate an explicit projection instead of the dictionary itself:

var scores Dict<str, i32> = {"alice": 7, "bob": 9}
for (var name str : scores.keys()) {
  print(name)
  print(scores[name])
}

The type checker currently rejects for (... : dict) directly.

break exits the nearest loop. continue skips to the next iteration.

for (var i i32 = 0; i < 10; i++) {
  if (i == 3) continue
  if (i == 7) break
  print(i)
}

Labels let you target an outer loop instead of only the innermost one.

outer: while (true) {
  for (var i i32 = 0; i < 10; i++) {
    if (i == 3) continue
    if (i == 7) break outer
  }
}

The repo also has error coverage for duplicate labels, unknown labels, and labels attached to non-loop statements.