Rounding out hash table functionality with lazy lists that

can walk table content in different ways.

* eval.c (op_dohash): Follow interface change of hash_next.
(eval_init): hash-keys, hash-values, hash-pairs and hash-alist
intrinsics introduced.

* filter.c (trie_compress): Follow interface change of hash_next.

* hash.c (hash_next): Silly interface which takes a pointer to
the iterator has changed to just take the iterator. The function
unambiguously returns nil when the iteration ends, so there
is no need to set the iterator variable to nil.
(maphash): Follows interface change of hash_next.
(hash_keys_lazy, hash_values_lazy, hash_pairs_lazy, hash_alist_lazy):
New static functions.
(hash_keys, hash_values, hash_pairs, hash_alist): New functions.

* hash.h (hash_next): Declaration updated.
(hash_keys, hash_values, hash_pairs, hash_alist): Declared.

* lib.c (make_half_lazy_cons): New way of constructing lazy cons,
with the car field specified.  It simplifies situations when the
previous cons computes the car of the next one. Why hadn't I thought of
this before?

* lib.h (make_half_lazy_cons): Declared.

* txr.1: Doc stubs for new hash functions.

* txr.vim: Highlighting for new hash functions.

1 files changed, 10 insertions, 0 deletions

diff --git a/lib.c b/lib.c
index 52197df1..51c584b0 100644
--- a/lib.c
+++ b/lib.c
@@ -1002,6 +1002,16 @@ val make_lazy_cons(val func)
   return obj;
 }
 
+val make_half_lazy_cons(val func, val car)
+{
+  val obj = make_obj();
+  obj->lc.type = LCONS;
+  obj->lc.car = car;
+  obj->lc.cdr = nil;
+  obj->lc.func = func;
+  return obj;
+}
+
 val lcons_fun(val lcons)
 {
   type_check(lcons, LCONS);