Filtering feature for variable substitution in output.

* filter.c, filter.h: New files.

* Makefile (OBJS): filter.o added.

* gc.c (mark_obj): Mark new alloc field of string objets.

* hash.c (struct hash): New member, userdata.
(hash_mark): Mark new userdata member of hash.
(make_hash): Initialize userdata.
(get_hash_userdata, set_hash_userdata, hashp): New functions.

* hash.h (get_hash_userdata, set_hash_userdata, hashp): New functions
declared.

* lib.c (getplist, string_extend, cobjp): New functions.
(string_own, string, string_utf8): Initialize new alloc field to nil.
(mkstring, mkustring): Initialize new alloc field to actual size.
(length_str): When length is computed and cached, also compute
and cache alloc.
(init): Call filter_init.

* lib.h (string string): New member, alloc.
(num_fast): Macro converted to inline function.
(getplist, string_extend, cobjp): New functions declared.

* match.c (match_line): Follows change of modifier s-exp syntax.
(format_field): New parameter, filter.
New modifier syntax parsed. Filter retrieved, and applied.
(subst_vars): New parameter, filter. Filter is either applied
in this function or passed to format_field, as needed.
(eval_form): Pass nil to new parameter of subst_vars.
(do_output_line): New parameter, filter. Passed down to subst_vars.
(do_output): New parameter, filter. Passed down to do_output_line.
(match_files): Pass nil filter to subst_vars in cat directive.
Output directive refactored to parse keywords, extract the
filter and pass down to do_output.

* parser.y (regex): Generate (sys:regex regex syntax ...)
instead of (regex syntax ...).
(elem, expr): Updated w.r.t. regex syntax change.
(var): Cases '{' IDENT regex '}' and '{' IDENT NUMBER '}'
are removed. new syntax '{' IDENT exprs '}' to handle these
more generally and allow for keywords.

* txr.1: Updated.

1 files changed, 31 insertions, 0 deletions

diff --git a/hash.c b/hash.c
index f26e83c2..dcd28011 100644
--- a/hash.c
+++ b/hash.c
@@ -51,6 +51,7 @@ struct hash {
   val table;
   cnum modulus;
   cnum count;
+  val userdata;
 };
 
 /*
@@ -141,6 +142,8 @@ static void hash_mark(val hash)
   struct hash *h = (struct hash *) hash->co.handle;
   cnum i;
 
+  gc_mark(h->userdata);
+
   switch (h->flags) {
   case hash_weak_none:
     /* If the hash is not weak, we can simply mark the table
@@ -235,6 +238,7 @@ val make_hash(val weak_keys, val weak_vals)
   h->modulus = c_num(mod);
   h->count = 0;
   h->table = table;
+  h->userdata = nil;
 
   return hash;
 }
@@ -258,6 +262,14 @@ val gethash(val hash, val key)
   return cdr(found);
 }
 
+val gethash_f(val hash, val key, val *found)
+{
+  struct hash *h = (struct hash *) hash->co.handle;
+  val chain = *vecref_l(h->table, num(ll_hash(key) % h->modulus));
+  *found = assoc(chain, key);
+  return cdr(*found);
+}
+
 val sethash(val hash, val key, val value)
 {
   val new_p;
@@ -275,6 +287,25 @@ val remhash(val hash, val key)
   return nil;
 }
 
+val get_hash_userdata(val hash)
+{
+  struct hash *h = (struct hash *) hash->co.handle;
+  return h->userdata;
+}
+
+val set_hash_userdata(val hash, val data)
+{
+  struct hash *h = (struct hash *) hash->co.handle;
+  val olddata = h->userdata;
+  h->userdata = data;
+  return olddata;
+}
+
+val hashp(val obj)
+{
+  return typeof(obj) == hash_s ? t : nil;
+}
+
 /*
  * Called from garbage collector. Hash module must process all weak tables
  * that were visited during the marking phase, maintained in the list