txr: close streams.

* match.c (noclose_k): New keyword variable.
(v_next_keys, v_output_keys): New static variables.
(v_next_impl): Use v_next_keys in calculating alist,
rather than freshly allocating it each time.
Check for the new :noclose keyword; if it is missing,
close any locally opened stream when done.
(v_output): Refer to v_output_keys precalculated
list rather than allocating it every time.
(match_files): If a stream is opened in by a call
to open_data_source from this function, then
the stream is closed when this function returns.
(syms_init): Intern the :noclose symbol.
(plist_keys_init): New function.
(match_init): Call plist_keys_init.

* txr.1: Documented new :noclose option of @(next).

1 files changed, 1 insertions, 1 deletions

diff --git a/match.h b/match.h
index b697cc0a..47b6070c 100644
--- a/match.h
+++ b/match.h
@@ -29,7 +29,7 @@
 extern val text_s, choose_s, gather_s, do_s, mdo_s, require_s, in_package_s;
 extern val close_s, load_s, include_s, mod_s, modlast_s, line_s;
 extern val else_s, elif_s;
-extern val counter_k, vars_k, lists_k, env_k, var_k, into_k, named_k;
+extern val counter_k, vars_k, lists_k, env_k, var_k, into_k, named_k, noclose_k;
 val match_expand_keyword_args(val elem);
 val match_expand_elem(val elem);
 val match_filter(val name, val arg, val other_args);