alt Hacker NewsI have always disliked the := as assignment operator convention. In these declarative languages, assignment is done frequently. There is little cognitive load to using '=' as assignment, although perhaps a bit jarring for math folk.
<- is somewhat better, but, again, for such a common operation, a single character is just more convenient. Sure, we could have editors that turn "=" into := or <- but now we're getting too fancy especially for something pedagogical.
I also don't mind the -> for C pointers; and certainly don't mind the <= >= or even == conventions (although at least today's compilers warn when they see "if (a=b) ...".
Ultimately, humans won't be writing code anymore anyway ( ;-) ?) so maybe the issue is entirely moot.
Replies
> I have always disliked the := as assignment operator convention. In these declarative languages, assignment is done frequently.
> I also don't mind the -> for C pointers
Mmm. These two opinions should be contradictory if held on principle as opposed being held out of impression.
it = next(it);
if ((*it)->node->op == EQ) ...
it := next(it);
if it.node.op = EQ ...
Technically, if you don't make assignment an expression, you can even get away with using "=" for both. And "->" exists only because structs originally weren't really typechecked; you could take any pointer and just do "->struct_field" at it, and the compiler would auto-cast.
Using '=' for both assignment and comparison is awkward when parsing incomplete code. Consider e.g.:
The user starts writing (<|> is the cursor position): This is a valid expression (i is a boolean). But the user probably intends to finish writing something like: So in the intermediate state we would like to emit a single warning about an incomplete statement. But since it is valid as written, we instead end up warning about e.g. j being unbound.