X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2FDEVEL%2Flablgtk%2Flablgtk_20000829-0.1.0%2Fexamples%2Fold%2Ffixpoint.ml;fp=helm%2FDEVEL%2Flablgtk%2Flablgtk_20000829-0.1.0%2Fexamples%2Fold%2Ffixpoint.ml;h=c41b11b50b6d9ec4813f7ff92919f1c19b283ac8;hb=2ee84a2a641938988703e329aef9fc3c5eb5aacf;hp=0000000000000000000000000000000000000000;hpb=34d83812af9b7064cc8f735c2a78169881140010;p=helm.git

diff --git a/helm/DEVEL/lablgtk/lablgtk_20000829-0.1.0/examples/old/fixpoint.ml b/helm/DEVEL/lablgtk/lablgtk_20000829-0.1.0/examples/old/fixpoint.ml
new file mode 100644
index 000000000..c41b11b50
--- /dev/null
+++ b/helm/DEVEL/lablgtk/lablgtk_20000829-0.1.0/examples/old/fixpoint.ml
@@ -0,0 +1,39 @@
+(* $Id$ *)
+
+open GtkData
+open GtkBase
+open GtkPack
+open GtkWindow
+open GtkEdit
+open GtkMain
+
+let rec fix fun:f :eq x =
+  let x' = f x in
+  if eq x x' then x
+  else fix fun:f :eq x'
+
+let eq_float x y = abs_float (x -. y) < 1e-13
+
+let _ =
+  let top = Window.create `TOPLEVEL in
+  GtkSignal.connect sig:Object.Signals.destroy top callback:Main.quit;
+  let hbox = Box.create `VERTICAL in
+  Container.add top hbox;
+  let entry = Entry.create () in
+  Entry.set entry max_length:20;
+  let tips = Tooltips.create () in
+  Tooltips.set_tip tips entry text:"Initial value for fix-point";
+  let result = Entry.create () in
+  Entry.set result max_length:20 editable:false;
+  Box.pack hbox entry;
+  Box.pack hbox result;
+
+  GtkSignal.connect sig:Editable.Signals.activate entry callback:
+    begin fun () ->
+      let x = try float_of_string (Entry.get_text entry) with _ -> 0.0 in
+      Entry.set entry text:(string_of_float (cos x));
+      let res = fix fun:cos eq:eq_float x in
+      Entry.set result text:(string_of_float res)
+    end;
+  Widget.show_all top;
+  Main.main ()