hash: implement :eq-based.

We need eq based hash tables to fix a problem in *print-circle*.

* hash.c (enum hash_type, hash_type_t): New enum type.
(eq_based_k): New keyword variable.
(eq_hash, eq_hash_op): New static functions.
(hash_print_op): Ensure we print eq-based hashes with the
correct keyword.
(hash_assq, hash_aconsq_new_c): New static functions.
(hash_eq_ops): New static structure.
(do_make_hash): New function, made from previous contents of
make_seeded_hash.
(make_seeded_hash): Wrapper around do_make_hash now.
(make_eq_hash): New function.
(hashv): Parse out :eq-based argument. Use make_eq_hash if it
is present.
(hash_init): Initialize eq_based_k.

* hash.h (eq_based_k, make_eq_hash): Declared.

1 files changed, 3 insertions, 1 deletions

diff --git a/hash.h b/hash.h
index 82d07528..da30adab 100644
--- a/hash.h
+++ b/hash.h
@@ -25,11 +25,13 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-extern val weak_keys_k, weak_vals_k, equal_based_k, eql_based_k, userdata_k;
+extern val weak_keys_k, weak_vals_k, userdata_k;
+extern val equal_based_k, eql_based_k, eq_based_k;
 
 ucnum equal_hash(val obj, int *count, ucnum);
 val make_seeded_hash(val weak_keys, val weak_vals, val equal_based, val seed);
 val make_hash(val weak_keys, val weak_vals, val equal_based);
+val make_eq_hash(val weak_keys, val weak_vals);
 val make_similar_hash(val existing);
 val copy_hash(val existing);
 val gethash_c(val self, val hash, val key, loc new_p);