Error handling

HDC’s error handling happens entirely at compile time — there’s no try/catch inside a script, because the device only ever executes bytecode that already passed every check on your computer. When something in a script is wrong, HiveFusion Studio’s console shows a compiler-style diagnostic instead of silently producing a broken payload:


error[ERR_UNKNOWN_KEY]: Unknown or unsupported key
 --> line 4
  |
4 |  CTRL SHFIT ESCAPE
  |       ^^^^^^^^^^^^
  |
  = help: This key is not recognized by the device.
          Make sure you are using a valid key name.

Every diagnostic follows the same shape: an error code and message, the line it happened on, the offending source with a caret pointing at it, and a help note explaining how to fix it. A few of the categories you’ll run into:

Category	Example
Unknown token	A misspelled or unsupported command.
Unknown / unsupported key	A key name the device doesn’t recognize.
Missing or invalid argument	`DELAY` with no number, or a non-numeric value where one is required.
Structural errors	An unterminated `STRING_BLOCK`, `FUNCTION` or `BUTTON_DEF`; a stray `END_` keyword with nothing open; a duplicate or nested block.
Function errors	Calling a function that was never defined, redefining one, or nesting definitions.

A compile error always stops the compile — nothing partially-correct is ever uploaded to the device.