On 28.04.2017 08:01, Ryan Joseph wrote: > >> On Apr 28, 2017, at 12:43 PM, Sven Barth via fpc-pascal >> <fpc-pascal@lists.freepascal.org> wrote: >> >> It would introduce an ambiguity as "(x" could also complete to other >> expressions (e.g. "(x + y) * 2" or even merely "(x)"). Especially older >> Pascal compilers were geared towards the simplicity of the language and thus >> they didn't add it. For FPC it simply never came up. > > I never thought about it either until I saw some c++ code doing it. Despite > having overlooked it, it’s basically a built in record constructor that’s > been in the language since forever. First it was making functions that paired > with records and now it’s constructors and "advanced record syntax" when the > more obvious and simpler solution was there all along. Maybe I’m crazy > though. ;) > > You mean like: > > rec := (x: (x + y) * 2; y: 0; z: 0);
No, I mean rec := (x + y) * 2; The compiler has to differentiate these two. > Why can’t everything between : and ; just be treated like a normal > assignment? “x” is already defined but it’s just a label and not part of the > assignment. And that's another point. The compiler does not know what "x", "y" and "z" are, cause it doesn't care about the left hand side of the assignment until *after* the right hand side is parsed (in a var/const section it knows the type; that's a different situation). So a different syntax would be needed that would allow the compiler to know that it's parsing a specific record type. >> >> The compiler currently prefers to cast array constructors towards sets, >> especially if they contain values that could be expressed as a set. That >> will change once proper support for array constructors is added. Though I >> don't know whether this would work then ;) > > Huh, that syntax works in constructors, just not in the operator overloading. > Anyways I guess I’ll just assume that’s not implemented behavior. Because in that case it knows that it's a parameter and handles that differently. A type conversion is a different case. Regards, Sven _______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
