Re: Character literals for Unicode (control) characters

[Paul Eggert]

Thanks for taking this on. Some comments:

Why the hash table? Existing Lisp code dealing with Unicode names uses an alist, 
and it seems to do OK. If a hash table is needed, a hash table should also be 
used by the existing code elsewhere that does something similar. See the 
function ucs-names and its callers.

If a hash table is needed, I suggest using a perfect hashing function (generated 
by gperf) and checking its results with get-char-code-property. That avoids the 
runtime overhead of initialization.

It needs documentation, both in the Emacs Lisp manual and in NEWS.


> +void init_character_names ()
> +{

The usual style is:

void
init_character_names (void)
{


No need for "const" for local variables (cost exceeds benefit).


>             if (c_isspace (c))
>               {
>                 if (! whitespace)
>                   {
>                     whitespace = true;
>                     name[length++] = ' ';
>                   }
>               }
>             else
>               {
>                 whitespace = false;
>                 name[length++] = c;
>               }

This would be a bit easier to follow (and most likely a tiny bit more efficient) 
as something like this:

>       bool ws = c_isspace (c);
>       if (ws)
>         {
>           length -= whitespace;
>           c = ' ';
>         }
>       whitespace = ws;
>       name[length++] = c;