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May 29
Gravatar of KagaminPosted by KagaminReply
Kagamin
Gravatar of Kagamin


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https://c3-lang.org/language-common/optionals-advanced/
The language is quite nice, resembles BetterC, but also the first ergonomic language where I see the Result type in action. Result is also used for nullable types.

// Function returning an Optional
fn int? maybe_func() { /* ... */ }

fn void? test()
{
	// ❌ This will be a compile error
	// maybe_function() returns an Optional
	// and 'bar' is not declared Optional:
	// int bar = maybe_function();

	int bar = maybe_function()!;
	// ✅ The above is equivalent to:
	// int? temp = maybe_function();
	// if (catch excuse = temp) return excuse?;

	// Now temp is unwrapped to a non-Optional
	int bar = temp; // ✅ This is OK
}

But striving to be evolution of C, faults look like error code singletons and apparently don't carry much information.

May 29
Gravatar of Ali ÇehreliPosted by Ali Çehreli
in reply to Kagamin		Reply
Ali Çehreli
Gravatar of Ali Çehreli
Posted in reply to Kagamin


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On 5/29/25 1:18 PM, Kagamin wrote:

> But striving to be evolution of C, faults look like error code
> singletons and apparently don't carry much information.

Same here.

I've been using a macro system in a C++ library that exposes a C API. All implementation functions return an optional type that automatically errors if not checked. Equivalents of enforce(), assert(), etc. automatically return an invalid optional.

Here is your point: There is a constant-length buffer that collects a backlog of error messages from function calls. Exhausting the buffer is not an error; the lowest-level error messages are retained. That buffer is just 4K, which is 0 bytes to my eyes :).

The caller of the C API receives a C array of error strings that they can print to see exactly what happened. Sweet...

Oh... oh... and all formatted error messages are actually generated in a development build even when there are no errors, to prove that error messages will render and look correct when generated. (The buffer is a lot larger in that case, not 4K.) Very sweet indeed... :)

Ali