Experimental Physics and
Industrial Control System

Michael Davidsaver via Tech-talk <tech-talk at aps.anl.gov> · Mon, 8 Jun 2020 14:08:47 -0700

I'm looking to collect examples of epics record names in the wild.

This is an early step towards (maybe) adding restrictions on what
characters a record name can contain, and in what positions.
eg. restricting possible first and last characters.

In particular I'm looking for examples including characters
beyond the usual alphanumeric separated by ':' or '-'.
And in what positions they may (or may not) appear.

An example from the NSLS2 naming convention (for which I am have
some responsibility).

> TST{evm:1D-DlyGen:31}Evt:Trig2-SP

Which is notable for containing "{" and "}" in the middle.

As background.  At present, records can be created with almost
any characters in a name.

> record(ai, "a b") {}
> record(ai, "x.y") {}
> record(ai, "x\"") {}

However, record names including '.' can't be addressed and aren't
very useful.  Further, names including spaces can't be targeted
by links.

On the subject of links.  Dirk was surprised to find that
the syntax for link parsing treats "[0]" as a record name,
but "[0,1]" as a constant array.

https://bugs.launchpad.net/epics-base/+bug/1882520

Rather than carving out another exception, I'd like to look at
coding a general rule.

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System