Initial data commit

Task/History-variables/PureBasic/history-variables.basic

@@ -0,0 +1,49 @@
+; integer history variable
+
+Structure historyint
+    List value.i()
+EndStructure
+
+Procedure SetInt (*var.historyint, val.i)
+    AddElement(*var\value())
+
+    If (ListSize(*var\value()) = 1)
+        *var\value() = 0
+        AddElement(*var\value())
+
+    EndIf
+
+    *var\value() = val
+EndProcedure
+
+Procedure ShowHistory (*var.historyint)
+    ForEach *var\value()
+        Debug *var\value()
+    Next
+EndProcedure
+
+Procedure UndoInt (*var.historyint)
+    If (ListSize(*var\value()) = 1)
+        ProcedureReturn
+    EndIf
+
+    DeleteElement(*var\value())
+EndProcedure
+
+;----------------------------------------------
+
+Define x.historyint
+
+For i = 0 To 3
+    setint(x, Random(50)+100 )
+Next
+
+Debug "x history:"
+ShowHistory(x)
+
+Debug ""
+
+For i = 0 To 3
+    UndoInt(x)
+    Debug "undo, x = "+Str(x\value())
+Next