doc: fix call-super-fun error and add example.

* txr.1: call-super-fun method intro paragraph wrongly refers
to call-super-method. Adding example about how to call a base
class method.

1 files changed, 23 insertions, 1 deletions

diff --git a/txr.1 b/txr.1
index c49180bb..4c0abd76 100644
--- a/txr.1
+++ b/txr.1
@@ -24375,7 +24375,7 @@ not to the type against which the calling method is defined.
 .syne
 .desc
 The
-.code call-super-method
+.code call-super-fun
 retrieves the function stored in the slot
 .meta name
 of the supertype of
@@ -24395,6 +24395,28 @@ must name a static slot of that structure type.
 The object retrieved from that static slot must be
 callable as a function, and accept the arguments.
 
+.TP* Example:
+
+Print a message and call supertype method:
+
+.cblk
+  (defstruct base nil)
+
+  (defstruct derived base)
+
+  (defmeth base fun (obj arg)
+    (format t "base fun method called with arg ~s\en" arg))
+
+  (defmeth derived fun (obj arg)
+    (format t "derived fun method called with arg ~s\en" arg)
+    (call-super-fun 'derived 'fun obj arg))
+
+  ;; Interactive Listener:
+  1> (new derived).(fun 42)
+  derived fun method called with arg 42
+  base fun method called with arg 42
+.cble
+
 .coNP Macro @ with-objects
 .synb
 .mets (with-objects >> ({( sym << init-form )}*) << body-form *)