Universal variables gave me a crazy idea. I don't know yet what to do about it, so I decided to toss it here rather than think alone.
Builtins and functions are evil from the user's perspective, because they are invisible to other programs. E.g. last week I tried ``env BROWSER=links help ...`` which of course didn't work because `help` is a function. Which means that `env` can't fully replace the requested set-for-one-command feature. Why do we have builtins at all? (1) Things like ``set`` are builtin because a subprocess can't modify the shell's state. (2) Things like ``while ... end`` are builtins to have special syntax recognized by the parser. Functions are essentially builtin scripts, existing for reason (1). But (1) is not a reason, as fishd proves: if the shell becomes a server, things like ``set`` and ``cd`` can be implemented as external commands! This is perhaps an immediately good idea. As for (2), it is possible to turn control structures into external commands, but it requires going a long way toward TCL. Consider `xargs`: it's essentially a for loop (at least in -1 mode). And `watch` is a ``while true`` loop with some output wrapping. The trick is to supply the body as an argument, quite like in TCL. It means you need to quote multiple, perhaps nested commands in some way. More importantly, it means parsing of command boudaries can't depend on the command being used (because it's external). Both lead almost inevitably to TCL-style quoting with symentric delimiters, e.g. ``while COMMAND [CMD; CMD]`` instead of ``while COMMAND; CMD; CMD; end``. I have a growing feeling that TCL got this aspect right but it's obviously a very major change. -- Beni Cherniavsky <[EMAIL PROTECTED]>, who can only read email on weekends. ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Fish-users mailing list Fish-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/fish-users
