Generating unique identifiers at compile time
Hi,
As an experiment I have implemented the following kind of pattern
matching
(by parsing the part of the string before '=').
```d
struct S {
int x;
int y;
}
struct T {
int w;
S s;
}
void main()
{
mixin(matchAssign(q{auto T(first,S(second,third)) =
T(1,S(2,3));}));
first.writeln; // 1
second.writeln; // 2
third.writeln; // 3
}
```
In doing so I wanted to produce unique identifiers (something
like gensym in racket.) I did this in a very hacky way:
```d
auto hopefullyUniqueName(size_t n, size_t line=__LINE__) {
return
format!"var___%s%s"(n,line);
}
```
where I pass in the hash of the right hand side in the assignment
in place of n.
Is there some way to ask the compiler for a unique name or a
better way of achieving this?
Re: Generating unique identifiers at compile time
On Thursday, 9 June 2022 at 21:20:27 UTC, JG wrote:
Hi,
As an experiment I have implemented the following kind of
pattern matching
(by parsing the part of the string before '=').
```d
struct S {
int x;
int y;
}
struct T {
int w;
S s;
}
void main()
{
mixin(matchAssign(q{auto T(first,S(second,third)) =
T(1,S(2,3));}));
first.writeln; // 1
second.writeln; // 2
third.writeln; // 3
}
```
In doing so I wanted to produce unique identifiers (something
like gensym in racket.) I did this in a very hacky way:
```d
auto hopefullyUniqueName(size_t n, size_t line=__LINE__) {
return
format!"var___%s%s"(n,line);
}
```
where I pass in the hash of the right hand side in the
assignment in place of n.
Is there some way to ask the compiler for a unique name or a
better way of achieving this?
No, for now there if there are other ways they are as hacky as
yours.
The compiler usually uses a global counter to generate
temporaries.
There's [been attempts] to expose it, exactly so that users can
generate unique names, but that did not found its path in the
compiler.
[been attempts]: https://github.com/dlang/dmd/pull/10131
Re: Generating unique identifiers at compile time
On Thursday, 9 June 2022 at 23:50:10 UTC, user1234 wrote: There's [been attempts] to expose it, exactly so that users can generate unique names, but that did not found its path in the compiler. [been attempts]: https://github.com/dlang/dmd/pull/10131 You can generate unique names actually by using CTFE RNG, so it's not really necessary to have it exposed to achieve that. See my hacky example of hidden class members here: https://forum.dlang.org/thread/siczwzlbpikwlevvi...@forum.dlang.org
