Re^2: Why does Perl have typeglobs?

[Anonymous Monk]

Because they are symbol table entries ... the symbol table, where completely unrelated things (variables) are held

You know, Perl is not the only programming language that makes use of symbol tables! And other language (that I know of) dont have anything like typeglobs.

Hmm, six individual variables tables, versus one umbrella table, hmmm

? Why would you need different symbol tables? Different keys for different things would suffice. Perl's symbol table is just a hash... (well, I would be REALLY surprized if it weren't so)

But now that I think of it, yeah... It was probably an attempt to save memory. Smaller symbol tables, fewer structs in them, fewer calls to malloc... That kind of fits with the idea context. Still pretty strange. I'm sure Perl programmers don't use that feature very often, if at all.

[choroba]

Perl's symbol table is just a hash

Indeed. A hash of hashes, in a way:

use warnings;
use strict;
sub T { 42 }
our $T = 24;
*T = *STDOUT{IO};
print { *T{IO} } ${*T{SCALAR}}, ' ', *T{CODE}->(), "\n";

[ikegami]

Not a hash of hashes, a hash of globs. Not only is the syntax different, so is the implementation. A glob is a struct, not a hash table.