errors & diagnostics

compile errors (import/reload time)

when a script fails to compile like during /katton import, you get an exact location and a specific reason:

import failed: compilation failed
  leap_wand:error [leap_wand.kat:7:12] function parameters cannot have types: use function name(a, b)

reading this: script name leap_wand, file leap_wand.kat, line 7, column 12. open your script, go to that exact spot, and fix it.

common compile errors and what they mean:

message	what it means
`function parameters cannot have types`	you wrote `function f(a: Type)`, remove the `: Type`
`@Katton.command requires a 'name' argument`	you forgot `name = "..."` in the annotation
`invalid permission '...'`	`permission` must be exactly `"admin"`, `"creative"`, or `"all"`
`duplicate command name '...' within this script`	you used the same `name = "..."` on two commands in one script
`command name '...' is already used by your script '...'`	you used the same command name across two different scripts you own
`unknown event "..."`	check spelling against the event list
`an annotation must be immediately followed by a function declaration`	you put something between `@Katton.command(...)` and the `function` line
`unclosed { somewhere below` / `unexpected }`	brace mismatch, count your `{` and `}`

runtime errors (while a script is running)

these happen while a script is actually executing, a command run, an event firing, or a scheduled callback. you will get a chat message identifying the script, function, and line:

leap_wand:onLeap() [line 14] division by zero

common runtime errors:

message	cause
`division by zero`	you divided or took `%` of something by `0`
`undefined variable '...'`	typo'd a variable name, or used one before declaring it
`cannot reassign 'val ...'`	you tried to reassign something declared with `val`, use `var` instead
`list index N out of bounds`	you indexed past the end of a list, check `.size()` first
`missing required argument '...'`	you called a builtin function without a required parameter