Hi Stephen,
On Sun, Nov 6, 2016 at 4:44 PM, Stephen R. van den Berg <s...@cuci.nl> wrote:
> Why would you warn for this?
> Or, to put it differently: why would it be better to avoid using the
> dot operator to index dynamically?
The problem mostly is that it is easy to mistake . as equivalent to
-> while it is not.
For example:
Pike v8.1 release 6 running Hilfe v3.5 (Incremental Pike Frontend)
> ADT.List l = ADT.List();
> l->insert(1);
Compiler Warning: 1: Returning a void expression. Converted to zero.
(1) Result: 0
> l.insert(2);
Compiler Warning: 1: Using . to index dynamically.
Bad argument 1 to `[](). Expected int.
Unknown program: `[]("insert")
-:1: ADT.List(/* 1 element */
1
)->`[]("insert")
HilfeInput:1: HilfeInput()->___HilfeWrapper()
Another problem is that when . is used instead of -> on (object)
constants, you "suddenly" get a static index instead of a dynamic one.
I.e. imagine an environment where you have a constant object o of the
following program:
class X {
array a = ({ });
}
Then the following will not work as one might expect:
o.a += ({ "hello" });
write("%O\n", o.a); // outputs the empty array
We have seen multiple issues with users stumbling over this in a bad way.
