rfind-if: optimized rewrite and hash support.

* lib.c (rfind_if): Function rewritten to use the seq_info
sequence classification mechanism, for much better
performance on vector-like objects. Also, supports hash
tables just like find_if.

* txr.1: Documentation updated regarding hash support
of rfind-if.

1 files changed, 13 insertions, 1 deletions

diff --git a/txr.1 b/txr.1
index d7f3ad91..26bc2051 100644
--- a/txr.1
+++ b/txr.1
@@ -27491,7 +27491,7 @@ then these cells are taken as their keys.
 .coNP Functions @ rfind and @ rfind-if
 .synb
 .mets (rfind < key < sequence >> [ testfun <> [ keyfun ]])
-.mets (rfind-if < predfun < sequence <> [ keyfun ])
+.mets (rfind-if < predfun >> { sequence | << hash }  <> [ keyfun ])
 .syne
 .desc
 The
@@ -27509,6 +27509,18 @@ in
 they return the right-most element rather than
 the leftmost.
 
+In the case of
+.code rfind-if
+when a
+.meta hash
+is specified instead of a
+.metn sequence ,
+the function searches through the hash entries in the same order as
+.codn find-if ,
+but finds the last match rather than the first.
+Note: hashes are inherently not ordered; the relative order of items in
+a hash table can change when other items are inserted or deleted.
+
 .coNP Functions @ find-max and @ find-min
 .synb
 .mets (find-max >> { sequence | << hash } >> [ testfun <> [ keyfun ]])