Hot code reloading
V has built-in partial support for reloading code at runtime. Such programs change their behavior when the code changes without recompilation.
module main
import time
[live]
fn print_message() {
println('Hello! Modify this message while the program is running.')
}
fn main() {
for {
print_message()
time.sleep(500 * time.millisecond)
}
}
Build this example with v -live message.v.
You can also run this example with v -live run message.v.
Make sure that in command you use a path to a V's file, not a path to
a folder (like v -live run .) – in that case you need to modify content of
a folder (add new file, for example), because changes in message.v will have no effect.
Functions that you want to be reloaded must have [live]
attribute
before their definition.
Right now it's not possible to modify types while the program is running.
More examples, including a graphical application: Hot Reload Examples.