hash: move ops into static structure + bug found.

The four hash operations (hash, equal, assoc and acons) are
moved out of the hash instance and into a static table of
operations. This means we have to go through one more
indirection when calling them, but we save some space and
shorten initialization.

A bug is fixed here: the copy_hash function was only copying
three out of these four functions; the equal operation was
left uninitialized eposing the hash equality operation to
corrupt behavior. Now that function just copies the hops
pointer, so all is well.

* hash.c (struct hash_ops): New struct type.
(hash_ops_init): New macro.
(struct hash): hash_fun, equal_fun, assoc_fun and
assoc_new_c fun members removed. New member hops.
(hash_eql_ops, hash_equal_ops): New static structures.
(hash_equal_op): Compare the hops pointers rather than
just the hash_fun: if two hashes have different hops
pointers, they are different, period.
Indirect through ops for calling equal fun and others.
(hash_hash_op): Include the hops pointer in the hash,
rather than the hash_fun pointer.
(hash_print_op): Test for hash type (equal based or eql based)
now done by comparing the hops pointer to one of the two
static structures, rather than hash_fun to one of two
functions.
(make_hash, make_similar_hash, copy_hash): Initialize hops;
remove initializations for the four functions.
(gethash_c, gethash_e, remhash): Indirect through hops
to invoke hash operations.
(hash_uni, hash_diff, hash_isec): Incompatible hash check
based on comparing hops pointer rather than hash_fun.

0 files changed, 0 insertions, 0 deletions