Fatal

Reports an unrecoverable error and terminates the process.

Module: Std

Signature

func Fatal(
    message:  char8[],
    file:     char8[]  = #file,
    function: char8[]  = #function,
    line:     uint     = #line,
    column:   uint     = #column,
);

Parameters

Name	Type	Description
message	char8[]	A description of what went wrong.
file	char8[]	Source file of the call site. Supplied by the compiler — omit it.
function	char8[]	Function of the call site. Supplied by the compiler — omit it.
line	uint	Line of the call site. Supplied by the compiler — omit it.
column	uint	Column of the call site. Supplied by the compiler — omit it.

Description

Fatal prints message together with the call-site location, then exits the process with code 1. Use it for unrecoverable conditions where continuing execution makes no sense — a corrupt invariant, an unreachable branch, or a missing resource the program cannot run without.

The #file, #function, #line, and #column default arguments are substituted by the compiler at each call site, so callers pass only message.

WARNING

Fatal does not return — it terminates the process immediately. Any deferred work or cleanup after the call site will not run. For recoverable checks, prefer returning an error; for debug-only invariants, use Assert.

Example

import Std::Fatal;

func Main() -> int {
    let config = LoadConfig();
    if config == null {
        Fatal("could not load configuration");
    }
    // ... unreachable if config is null ...
    return 0;
}

Output:

Fatal error: could not load configuration
--> Src/Main.rux:6:9
    in function Main