3 files changed, 30 insertions, 21 deletions

diff --git a/ChangeLog b/ChangeLog
index d4cbb8ce..accf2a84 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2011-10-26  Kaz Kylheku  <kaz@kylheku.com>
+
+	Fixed lame @(cat) directive, without obsolescence phase.
+
+	* match.c (v_cat): Rewritten.
+
+	* txr.1: Documented.
+
 2011-10-25  Kaz Kylheku  <kaz@kylheku.com>
 
 	* configure: put in set -u to trap unbound variables, 
diff --git a/match.c b/match.c
index 5fe8782f..4b163af8 100644
--- a/match.c
+++ b/match.c
@@ -2242,25 +2242,24 @@ static val v_set(match_files_ctx c, match_files_ctx *cout)
 static val v_cat(match_files_ctx c, match_files_ctx *cout)
 {
   spec_bind (specline, spec_linenum, first_spec, c.spec);
-  val iter;
+  val sym = second(first_spec);
+  val sep_form = third(first_spec);
 
-  for (iter = rest(first_spec); iter; iter = rest(iter)) {
-    val sym = first(iter);
+  if (rest(specline))
+    sem_error(spec_linenum, lit("cat: obsolete syntax"));
 
-    if (!bindable(sym)) {
-      sem_error(spec_linenum,
-                lit("cat: ~s is not a bindable symbol"), sym, nao);
+  if (!bindable(sym)) {
+    sem_error(spec_linenum,
+              lit("cat: ~s is not a bindable symbol"), sym, nao);
+  } else {
+    val existing = assoc(c.bindings, sym);
+    if (existing) {
+      val sep = if3(sep_form, 
+                    cdr(eval_form(spec_linenum, sep_form, c.bindings)),
+                    lit(" "));
+      *cdr_l(existing) = cat_str(flatten(cdr(existing)), sep);
     } else {
-      val existing = assoc(c.bindings, sym);
-      val sep = nil;
-
-      if (rest(specline)) {
-        val sub = subst_vars(rest(specline), c.bindings, nil);
-        sep = cat_str(sub, nil);
-      }
-
-      if (existing)
-        *cdr_l(existing) = cat_str(flatten(cdr(existing)), sep);
+      sem_error(spec_linenum, lit("cat: unbound variable ~s"), sym, nao);
     }
   }
 
diff --git a/txr.1 b/txr.1
index 223f464d..b6445527 100644
--- a/txr.1
+++ b/txr.1
@@ -2043,15 +2043,17 @@ levels of nesting such that elements are at the appropriate depth.
 .SS The Cat Directive
 
 The @(cat) directive converts a list variable into a single
-piece of text. Optionally, a separating piece of text can be inserted
-in between the elements. This piece is written to the right of
-the @(cat) directive, and spans to the end of the line. It may
-contain variable substitutions.
+piece of text. The syntax is:
+
+ @(cat VAR [ SEP ])
+
+The SEP argument specifies a separating piece of text. If no separator
+is specified, then a single space is used.
 
 Example:
 
   pattern:      @(coll)@{a /[^ ]+/}@(end)
-                @(cat a):
+                @(cat a ":")
   data:         1 2 3 4 5
   result:       a="1:2:3:4:5"