Errors & Debugging

Understand compiler errors and runtime logs.

The validator

knight -check file.sa prints every problem with a line and column. Nothing runs until the file is clean.

text

file.sa:12:5: unknown function "SetPlayerHelth"
file.sa:20:1: expected ';' after event block (required by Knight syntax)
file.sa:30:9: cannot assign string to int variable "score"

Common compiler errors

Message	Cause and fix
`unknown function`	A typo or a native that does not exist. Check the native list.
`expected ';' after ...`	Missing `;` after a callback, function or config block.
`cannot assign ...`	The value type does not match the variable/field type.
`unknown event`	The callback name is not in the engine's list. See Callbacks.
`undefined variable`	Use the variable before declaring it, or a typo.
`argument N of X expects ...`	A built-in function was called with the wrong type.

Runtime behaviour

A runtime error in a callback is logged and does not crash the server.
Boolean callbacks fail open: if they error, the action is allowed.
Timers and database callbacks run on the tick loop; a slow callback delays everyone, so keep them fast.

Logging from a gamemode

knight

Log("player " + str(playerid) + " joined");
Log("value = " + str(len(parts)) + " / " + typeof(parts));

Inspecting state

knight

player::command("/debug") {
    SendClientMessage(playerid, "hp={GetPlayerHealth(playerid)} pos={GetPlayerPos(playerid)}");
    Log("money=" + str(GetPlayerMoney(playerid)));
};

Tip

Run knight -ast file.sa to see exactly how the parser read your file when an expression behaves unexpectedly.