title: CS-DROP
description:
  CS-DROP             "c-s-drop"

  Interpretation: Interpretation semantics for this word are undefined.

  Execution: ( C: orig|dest -- )

  Remove the top element from the control-flow stack. An ambiguous condition exists if the top control-flow stack item is not an orig or dest.


status: proposed for ANSI standardization, "seconded"

---

proposal:
Add CS-DROP to TOOLS EXT

Add the word CS-DROP to the Programming-Tools extension word set with the following specification:

15.6.2.???? CS-DROP             "c-s-drop"      TOOLS EXT

     Interpretation: Interpretation semantics for this word are undefined.

     Execution: ( C: orig|dest -- )

Remove the top element from the control-flow stack. An ambiguous condition exists if the top control-flow stack item is not an orig or dest.

In this connection, modify "15.6.2.1015 CS-PICK" to be:

15.6.2.1015   CS-PICK           "c-s-pick"   TOOLS EXT

     Interpretation: Interpretation semantics for this word are undefined.

      Execution:

               ( C: origu|destu ... orig0|dest0 -- origu|destu ... orig0|dest0 origu|destu )
               ( S: u -- )


Remove u. Copy origu|destu to the top of the control-flow stack. An ambiguous condition exists if there are less than u+1 items, each of which shall be an orig or dest, on the
control-flow stack before CS-PICK is executed.

If the control-flow stack is implemented using the data stack, u shall be the topmost item on the data stack.

An ambiguous condition exists if the same orig value is resolved multiple times.

and extend "15.4.1.2 Ambiguous conditions":

15.4.1.2 Ambiguous conditions

- resolving the same orig value multiple times