[Info-vax] DCL's flaws (both scripting and UI)

[David Jones]

On Thursday, September 10, 2020 at 11:11:15 AM UTC-4, David Jones wrote:
> Having a library that takes over command line editing and allows editing long 
> lines is certainly doable (almost certainly requiring a discrete $QIO for every 
> keypress), but no one is going to invest the required effort. 
> 

I've been investigating what it takes to do multi-row editing at the application
level and it's pretty fiddly. Just to make it easier to keep of where the cursor is,
you temporarily set the terminal mode /nowrap and do all your reads trmnoecho.
You also intercept broadcasts via a mailbox so you can display it and cleanly
refresh the input line (with prompt). If you're using SMG for device independence,
you encounter the inexplicable things like ctrl-X get mapped to ctrl-U so you can't
have one mean 'clear input buffer' and the other mean 'erase back to start of
current line'.