Re: hash-table-{to, from}-alist

[David De La Harpe Golden <david@harpegolden.net>]

Stefan Monnier wrote:
>>         #s<hash-table size 65 test 'eql weak 'key rehash-size 20.0 rehash-threshold 0.001 data (1 2 5 env )>
> 
> Looks OK, except I don't think it's a good idea to include ' in front of
> key and eql.  I know it's what we do right now, but in order to read it
> back in, it's going to be more trouble.  Also I'd generally prefer using
> ":weakness" rather than "weak", so it's as close as possible to the key
> args passed to make-hash-table.
>

The #s kind of bothers me.  In common lisp, #s(a ...) is readable - as 
an instance of struct a [*]. Hence the "s". Now, hashtables may well use 
a struct for their metadata as an implementation detail, but the #s<...> 
does look to me like an odd mix of commmon lisp #s(...) 
struct-instance-literal syntax and #<...> 
printable-but-unreadable-object syntax.

I realise that for emacs lisp compatibility with common lisp is a 
nongoal and compatibility with xemacs lisp is of some interest, so it's 
not a huge argument against #s<...>,  I'm just saying I'm finding it a 
bit confusing coming from CL (mind you, CL anyway lacks any print/read
roundtripping hashtable syntax)

[*]
CL-USER> (defstruct a b c)
A
CL-USER> (make-a :b 1 :c 2)
#S(A :B 1 :C 2)
CL-USER> #s(a :b 2 :c 3)
#S(A :B 2 :C 3)
CL-USER>