opip: pass through forms in the op family.

* stdlib/op.tl (sys:opip-expand): Add op, do, lop, ldo, ap,
ip, ado, ido, ret and aret to the operators whose forms are
passed through untransformed. This is important because it
lets us override the implicit (op ...) and (do ...) chosen
by the expander. When a pipeline element produces a list, for
instance, we want to be able to use (ap ...) in the next
element to spread the list into arguments.

* tests/012/op.tl: Add bellied numbers test case.

* txr.1: Documented.

1 files changed, 21 insertions, 4 deletions

diff --git a/txr.1 b/txr.1
index 03386c86..b1cf7148 100644
--- a/txr.1
+++ b/txr.1
@@ -56777,16 +56777,31 @@ where the above
 notation denotes the following transformation applied to each argument:
 
 .verb
-  (function ...) -> (op function ...)
-  (operator ...) -> (do operator ...)
-  (macro ...)    -> (do macro ...)
+  ;; these specific form patterns are left untransformed:
+
   (dwim ...)     -> (dwim ...)
   [...]          -> [...]
   (qref ...)     -> (qref ...)
   (uref ...)     -> (uref ...)
+  (op ...)       -> (op ...)
+  (do ...)       -> (do ...)
+  (lop ...)      -> (lop ...)
+  (ldo ...)      -> (ldo ...)
+  (ap ...)       -> (ap ...)
+  (ip ...)       -> (ip ...)
+  (ado ...)      -> (ado ...)
+  (ido ...)      -> (ido ...)
+  (ret ...)      -> (ret ...)
+  (aret ...)     -> (aret ...)
   .slot          -> .slot
   .(method ...)  -> .(method ...)
   atom           -> atom
+
+  ;; other compound forms are transformed like this:
+
+  (function ...) -> (op function ...)
+  (operator ...) -> (do operator ...)
+  (macro ...)    -> (do macro ...)
 .brev
 
 In other words, compound forms whose leftmost symbol is a macro or operator
@@ -56802,7 +56817,9 @@ denoting struct slot access, either explicitly using
 .code uref
 or
 .code qref
-or the respective dot notations, as well as any atom forms.
+or the respective dot notations, forms which invoke any of the
+.code do
+family of operators, as well as any atom forms.
 
 Note: the
 .code opip