Control flow

Gofra provides conditional execution and looping constructs.

`if`

Executes a block if the condition is true.

<condition> if
    <body>
end

1 1 == if
    "true" print
end

<condition> if
    <then>
else
    <else>
end

1 0 == if
    "equal" print
else
    "not equal" print
end

Repeats a block while the condition is true.

while
    <condition>
do
    <body>
end

The condition is evaluated before each iteration.

var counter int = 0

while
    counter 10 <
do
    counter print_integer
    &counter counter 1 + !<
end

Iterates over a range or a array. Ranges are exclusive on the upper bound.

for i in 0..10 do
    // i = 0, 1, 2, ..., 9
end

Reversed ranges count down:

for i in 10..0 do
    // i = 9, 8, ..., 0
end

var x = 5

for i in 0..x do
    // i = 0, 1, 2, 3, 4
end

Step is always 1

for ranges always step by 1 (or −1 for reversed ranges). There is no custom step.

var xs = [5, 6, 7]

for i in 0..xs do
    // i = 0, 1, 2 (index)
end

for x in xs do
    // x = *5, *6, *7 (pointer to each element)
end

Pointer iteration

for x in xs iterates by pointer: x is a pointer to the current element, not a copy of its value.

for i in 0..10 is lowered to:

var i int = 0
while
    i 10 <
do
    <body>
    &i i 1 + !<
end

For a reversed range (10..0), the comparison is > and the increment is -.