New list-builder method: oust.

* autoload.c (build_set_entries): Add oust symbol.

* stdlib/build.tl (list-builder postinit): Call the self
argument self instead of bc, for consistency with other
methods.
(list-builder oust): New method.
(list-builder-flets): Add local function oust.

* tests/012/seq.tl: New tests.

* txr.1: Documented.

* stdlib/doc-syms.tl: Updated.

2 files changed, 12 insertions, 4 deletions

diff --git a/stdlib/build.tl b/stdlib/build.tl
index 3837f43f..e5cba268 100644
--- a/stdlib/build.tl
+++ b/stdlib/build.tl
@@ -28,9 +28,16 @@
 (defstruct list-builder ()
   head tail
 
-  (:postinit (bc)
-    (set bc.head (cons nil bc.head)
-         bc.tail bc.head))
+  (:postinit (self)
+    (set self.head (cons nil self.head)
+         self.tail self.head))
+
+  (:method oust (self . lists)
+    (if lists
+      (let ((nl [apply append lists]))
+        (set self.tail (usr:rplacd self.head nl)))
+      (set self.tail (usr:rplacd self.head nil)))
+    self)
 
   (:method add (self . items)
     (let ((st self.tail))
@@ -112,7 +119,7 @@
 
 (defun sys:list-builder-flets (lb-form)
   (nconc
-    (collect-each ((op '(add add* pend pend* ncon ncon*)))
+    (collect-each ((op '(add add* pend pend* ncon ncon* oust)))
       ^(,op (. args)
          (qref ,lb-form (,op . args))
          nil))
diff --git a/stdlib/doc-syms.tl b/stdlib/doc-syms.tl
index 7a9348ee..95092836 100644
--- a/stdlib/doc-syms.tl
+++ b/stdlib/doc-syms.tl
@@ -1391,6 +1391,7 @@
       ("orec" "N-0003ED2C")
       ("orf" "N-01E7D2AD")
       ("ors" "N-02D33A3D")
+      ("oust" "N-0126D3FF")
       ("output" "N-0159EBE7")
       ("package-alist" "N-017F684C")
       ("package-fallback-list" "N-027A535C")