string hash

[spir <denis.spir@...>]

Hello,

I'd like to know whether the (only) purpose of strings storing their hash value 
is to avoid recomputing them when the string pool has to grow.

PS: Case interesting, I stepped some time ago on a rather new family of string 
hash funcs, "murmur", by people who also develop hash algo testers: 
http://code.google.com/p/smhasher/
Nearly unrelated, but who knows: there is also an interesting rather new 
pseudo-random generator, "wELL": http://www.iro.umontreal.ca/~panneton/WELLRNG.html
(I used both w/o any issue, cannot say anything of their quality myself, but 
they are fast, light, and academic studies validate them as of high quality.)