`give` statement with arbitrary expression produces invalid story file about inform6

[erkyrath]

Expressions should be valid there. This is a code generation bug.

(In the line give obj 1 + 1, the expression gets folded to a constant at compile time. That's why the bug doesn't show up.)

[erkyrath]

Whoops, hang on, I'm wrong about what happened.

The line give obj (1); is parsed as give X; where X is a function call obj(1). That's the ambiguity you were referring to. It's confusing because give X; is legal, according to the language def -- it gives the object X zero attributes.

Yeah, it's not obvious how to even detect this. We could warn on give X; but then the same problem occurs with give obj (1) light;.

Maybe the call syntax X(Y) can do some static type-checking.

[erkyrath]

On the other hand, the compiler should never produce an invalid file without complaining.

This is not a rule at all, I'm afraid. There are an infinite number of ways to produce an invalid story file. Calling X() where X is not a function is just one of them.

[Natrium729]

Ah, I didn't know it was possible to have a give statement without attributes. (And I also totally forgot about constant folding.)

In that case, yeah, the syntax is ambiguous but the compiler isn't wrong either, so I guess it's not a bug after all. (Although I would have thought interpreters would display an error message in the lines of "tried to call something that's not a routine".)

I suppose that, as you said, it should be possible to type-check routine calls, but that's not extremely important either.

[erkyrath]

#172 is the routine-call type check.

line 12: Warning:  In function call, expected Routine but found Object "obj"
>  give obj (1+1);

Of course this warning only appears when obj is an Object literal. If it's a local variable, the compiler can't help you.