string-extend: third optional argument.

A Boolean optional argument to string-extend indicates whether
this is likely the last call to string-extend, so memory can
be trimmed accordingly.

* eval.c (eval_init): Update string-extend registration.

* filter.c (trie_filter_string): Pass nil for new argument of
string_extend.

* lib.c (str_seq, replace_str,
lazy_str_force, lazy_str_force_upto): Pass nil for new
argument of string_extend.
(rem_impl, remove_if, separate): Pass t for new argument of
string_extend on last iteration, nil otherwise.
(string_extend): Implement new third argument, defaulted to
nil. Switch from chk_grow_vec to the more specific chk_wrealloc,
which simplifies the code.

* lib.h (string_extend): Declaration updated.

* parser.y (litchars): Pass t as last argument of
string_extend since we know syntactically that these
reductions finalize the string.
(restlitchar): Pass nil as the last argument of string_extend,
since we know syntactically that it isn't the last.

* regex.c (scan_until_common): Pass nil for new argument of
string_extend.

* txr.1: Documented.

1 files changed, 1 insertions, 1 deletions

diff --git a/eval.c b/eval.c
index 3dbbbf03..74ab1703 100644
--- a/eval.c
+++ b/eval.c
@@ -7143,7 +7143,7 @@ void eval_init(void)
   reg_fun(intern(lit("copy-str"), user_package), func_n1(copy_str));
   reg_fun(intern(lit("upcase-str"), user_package), func_n1(upcase_str));
   reg_fun(intern(lit("downcase-str"), user_package), func_n1(downcase_str));
-  reg_fun(intern(lit("string-extend"), user_package), func_n2(string_extend));
+  reg_fun(intern(lit("string-extend"), user_package), func_n3o(string_extend, 2));
   reg_fun(intern(lit("stringp"), user_package), func_n1(stringp));
   reg_fun(intern(lit("lazy-stringp"), user_package), func_n1(lazy_stringp));
   reg_fun(intern(lit("length-str"), user_package), func_n1(length_str));