Arc modules

Write Arc code one time in a module, and import it into your automations.

A module is Arc code that automations and other modules import. A module has no Driver and does not run by itself.

Create a module

1. In the Arcs toolbar, click Create Arc automation ().
2. Type a name, and select the Module type. The name can contain only letters, digits, and underscores.
3. Click Create.

Export code

Put export before a top-level function, sequence, stage, or := variable. Importers see only exported code.

export func psi_to_kpa() {v f64} f64 {
    return v * 6.895
}

export sequence press {
    stage fill {
        1 -> press_vlv_cmd
        tank_pt > 300 => next
    }
    stage hold {
        0 -> press_vlv_cmd
    }
}

export stage vent {
    0 -> press_vlv_cmd
    1 -> vent_vlv_cmd
}

Import a module

The import path is the directory names and the module name, joined by .. This automation imports the module tank from the directory lib:

import lib.tank

tank_pt -> tank.psi_to_kpa() -> tank_pt_kpa
start_cmd == 1 => tank.press
abort_cmd == 1 => tank.vent

An import can also use an alias or a group.

Edit a module

The controls bar shows “Compiled” or “Failed to compile” with the error.

A running automation keeps the module code that it started with until you redeploy it.

If you rename, move, or delete a module, each import of the old path fails with unknown module "lib.tank".

Rules