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For Loop

Flow-Wing supports the for keyword to iterate over a sequence of values.

Example Usage:​

for var i: int = 0 to 10  {
  print(i + " ")
}

Output:

0 1 2 3 4 5 6 7 8 9 10

Here, the for keyword is used to iterate over a sequence of values. The statement inside the loop is executed 11 times. The step : 1 is the default. Writing for (var i = 0 to 10) without : 1 is equivalent.

With Step​

Flow-Wing supports the for keyword to iterate over a sequence of values with a step.

Example Usage:​

for (var i: int = 0 to 10 : 2)  {
  print(i + " ")
}

Output:

0 2 4 6 8 10

Here, the for keyword is used to iterate over a sequence of values with a step. The statement inside the loop is executed 6 times.

Descending Loop​

Flow-Wing supports descending loops by using a negative step value.

Example Usage:​

/; Count down from 10 to 0
for (var i: int = 10 to 0 : -1) {
  print(i + " ")
}

Output:

10 9 8 7 6 5 4 3 2 1 0

Break and Continue​

Flow-Wing supports break and continue control flow statements inside a for loop.

Example Usage:​

/; Skip even numbers
for (var i: int = 0 to 10 : 1) {
  if (i % 2 == 0) {
      continue
  }
  print(i + " ")
}

Output:

1 3 5 7 9

For Loop with Array/Container​

Flow-Wing supports the for keyword to iterate over a sequence of values with a step.

Example Usage:​

type Person = {
  name: str
}
var people: Person[6] = [
  {name: "a"},
  {name: "b"},
  {name: "c"},
  {name: "d"},
  {name: "e"},
  {name: "f"}
]
for (var i: int = 0 to 5 : 1) {
  print(people[i].name + " ")
}

Using a variable from the outer scope (bounds)​

The loop control variable is introduced in the for head (var i: int = ...). You can still read other outer variables in the bounds and step:

type Person = {
  name: str
}
var people: Person[6] = [
  {name: "a"},
  {name: "b"},
  {name: "c"},
  {name: "d"},
  {name: "e"},
  {name: "f"}
]
var last: int = 5
for (var i: int = 0 to last : 1) {
  print(people[i].name + " ")
}