I don't think this is meant to happen

[crishog]

'd:\tmp'⎕ncreate ¯1
'd:\tmp'⎕nerase ¯1

So far so good, but

'd:\tmp'⎕ncreate ¨¯1
⎕NINFO ¯1
d:/tmp
'd:\tmp'⎕NERASE ¯1
FILE NAME ERROR: File name mismatch
'd:\tmp'⎕NERASE ¯1
∧
'd:/tmp'⎕NERASE ¯1

Does work

⎕NAMES also shows that the "\" has flipped to "/" after a call to ⎕NINFO

[Dick Bowman]

Some weeks ago I suggested to Dyalog that it would be preferable (at least for me) if we were able to set what we wanted to use as filename separator - normalising file names through ⎕NPARTS, which seemed like a sensible thing to do, throws up a number of problems if you then try to use the filenames with other Windows components.

You can see that Dialog themselves contort code to deal with this - look at the SALTUtils namespace.

On the whole, I'd like to see filename separator either as something we can specify ourselves or as a system constant determined by checking the host OS.

[Richard|Dyalog]

You are quite right; it is not meant to happen. Querying the name of a tied file with ⎕NINFO is not supposed to change the name associated with it - that it apparently has done breaks ⎕NERASE as you demontrate. We will raise a bug report for this and fix it.