henesy/limbo-errors

Some examples of limbo errors/warnings being unintuitive wrt root cause

Common Limbo Compiler Errors

cannot be qualified

tttfs.b:93: 'game' of type Game cannot be qualified with ->

In this case Game is an adt type and game is defined as game: Game.

What Limbo wants, is game to be defined as game: ref Game.

link typecheck

link typecheck main->init() 0/4244b354

Something similar to this means that your init() function's signature does not match what is expected.

For a program intended to be run from the shell, etc. the proper signature is similar to:

MyModuleName: module {
	init: fn(nil: ref Draw->Context, argv: list of string);
};

init(nil: ref Draw->Context, argv: list of string) {
...
}

Typically I see this when I drop the ref in ref Draw->Context somewhere.

are not compatible

poly.b:66: fn(a: T, b: T): int and fn(a: Integral, b: Integral): int are not compatible wrt eq
poly.b:66: function call type mismatch (fn[T](x: T, a: array of T): array of T vs fn[T](nil: ref Integral, nil: array of ref Integral): array of T)

The eq() function has the signature:

eq:		fn(a, b: Integral): int;

Note the absence of the ref keyword.

A satisfying implementation would resemble:

Integral: adt {
	n: int;
	eq:		fn(a, b: ref Integral): int;
	String:	fn(x: self ref Integral): string;
};

Integral.eq(a, b: ref Integral): int {
	return a.n == b.n;
}