Hi,

A while ago, Joerg brought up the idea of using perfect hashes for some 
of the keywords in mandoc.  I'm reviving this conversation because I'd 
like a uniform interface for the roff, mdoc, man, chars, and mdoc-args 
tables.  For the time being, each of these has its own method, which is 
error-prone, ugly, and bloated.

Perfect hashes make sense because the above data is fixed. Furthermore, 
they have no cost of allocation and have little overhead in terms of 
unused table-space.

Enclosed is a patch that implements this just for the mdoc macro names. 
   I used gperf as I don't have a new NetBSD box handy for nbperf.  (It 
doesn't matter which is used---I messed around with the generated code 
as it is.)

The speed-up is a bit more than 1% when repeatedly running mandoc over a 
set of manuals.  When running it with a large number of manuals on the 
command-line, the results are more or less the same.  Either way, the 
generated binary is slightly smaller.

I'm leaning toward implementing similar steps for all existing hash 
files.  Does anybody have any objections?  My intent in this isn't so 
much performance as uniform interfacing, code readability, correctness, 
and bloat.  All of these are covered by perfect hashes, at the cost of 
needing an external utility whenever the symbols change.

(I had to remove mdoc_macronames[] because there wasn't an immediate way 
to map back... I'll figure this out later, if nobody objects to the 
notion in the first place.)

Thoughts?

Kristaps

PS, a good hash for the roff symbols (ds/de) is also under 
investigation.  Any suggestions---not dbopen---on a hash table for all 
Unices?