On Mar 10,  1:13pm, Guenter Kuhn wrote:
> does anybody know, if there is a callable (supported or unsupported) MPE
> routine which does the standard REDO ?

There is an internal routine used by the CI (obviously).  It executes at
ring level 1 so it requires that the caller be privileged (as do almost
all of the MPE OS internal routines).  There is no REDO intrinsic.

> Any tips / hints will be greatly appreciated.

Generally there are two aspects of REDO: 1) the actual editing of a
string or characters (like being able to insert, delete, etc.) and
2) managing a command redo/history stack.

The CI supports the 1st aspect with the EDIT() function.  This function
accepts the same edits as the REDO command does.

:help edit

Syntax:     EDIT(string,editstr[,start])

Defn:       A CI evaluator function that offers full REDO-like
            editing of a string.

Type:       String

Example:    edit('abcdefg','>dd')
Result:     'abce'
Example:    edit('ab cd;g','dwd')
Result:     'cd;g'


> If this routine is currently not available, is this not an great enhancement
> idea ?

There was some talk in CSY a few years ago about making REDO and
history stack management an AIF, but that idea was dropped.

Jeff Vance, CSY

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