Errors Halt

XCX 2.2 Error Handling (Halt)

XCX uses a structured halt system for managing runtime conditions and errors.

Halt Levels

Level	Behavior	Use Case
`halt.alert`	Prints a message; execution continues.	Logging, non-critical warnings
`halt.error`	Prints to stderr; aborts the current frame.	Recoverable logic errors
`halt.fatal`	Prints a message; terminates the VM immediately.	Critical failure, security breach

Examples

halt.alert >! "Cache missed, fetching from DB...";

if (divisor == 0) then;
    halt.error >! "Division by zero!";
    return 0; --- Execution returns to caller from the recovery point
end;

if (NOT db.is_healthy()) then;
    halt.fatal >! "Database corrupted. Emergency shutdown.";
end;

Semantic and Runtime Panics

Certain invalid operations result in an automatic panic (equivalent to halt.fatal or halt.error depending on context):

Division by zero (arithmetic)
JSON Parse Failure: Invalid string in json.parse() results in an immediate VM exit.
Path Traversal: Using .. in store methods or absolute paths outside the project root triggers halt.fatal.
Recursion Depth: Exceeding 800 frames triggers halt.error.