[plt-dev] renaming programs in the distribution

In trying to balance all of the naming issues, I'm coming around to the
idea that `racket' can work both as the command tool as the program
runner. [For the record, Eli tried to convince me of that long ago.]


The rationale:

We want everything to be "Racket" (not "PLT" and not something
close-but-not-too-close like "rico") and we want a tool to group
commands (because the `git' experience seems definitive). With those
two constraints, giving `racket' the tool-launching job seems like the
only solution. At the same time, we'd really prefer `racket' to provide
a REPL and/or start a program.


Some supporting experience:

In the v4.0-series PLT Scheme, the `mzscheme' command-line syntax
stands out for its irregular and complex rules --- especially
considering that it was designed that way on purpose.

For example, `mzscheme -i -l scheme/base' means something completely
different than `mzscheme -l scheme/base -i'. Also, `mzscheme -l
scheme/base' means yet something else, despite the fact that `mzscheme'
and `mzscheme -i' are equivalent.

The complex rules let the `mzscheme' binary serve many roles: starting
a REPL, running a program, following a `#!' at the start of a Unix
script, and starting a REPL for a particular language. It's a kind of
complexity that gives the illusion of simplicity, because you just use
`mzscheme' to do lots of things.

Maybe the same kind of complexity works out for giving `racket' one
more job.


A proposal:

If you run

 racket <command> ....

where <command> doesn't have a "/", "\", or "." in it, then it's a
command dispatch. Any other use of `racket' could be like the current
`racket' command line.

   [Yes, weird and ugly. It's the sort of ad hoc rule that we'd
    normally flag as poor language design. But if it works out, then
    we'll get over it.]

This rule works for scripts that start

 #! racket

because the script name will be passed to `racket' as a full path,
which must at least have a "/". It will also work for common uses such
as

  racket x.rkt

since programs that you pass to racket tend to have a suffix on them.
If your file doesn't have a suffix, then you'll be forced to either use
the `run' command:

 racket run myprog

or tack a "./" (or ".\" under Windows) on the front:

 racket ./myprog

When you run just `racket' and get a REPL, something in the banner
should tell you to try `racket help' for information on other commands.


Following through with the remaining names:

If we go that route --- and I think it's worth a try --- that leaves us
with the problem of naming programs that currently start with "PLT".

My preference is still to turn `plt-web-server' into `racket
web-server', because the point of starting the web server is ultimately
to run some Racket code that you wrote. (Along the same lines, I think
it makes sense to add `scribble' and `slideshow' commands.) Giving the
web server some non-generic name seems ok, too. Changing
`plt-web-server' to `racket-web-server' seems awkward to me, because it
would be the only important command that starts `racket' but uses a
hyphen instead of a space.

The "PLT Games" executable doesn't fit anywhere, and maybe it's not
crucial that it has "Racket" in its name. Leaving it as "PLT Games"
could be ok.

Finally, just leave `plt-r5rs' and `plt-r6rs' alone, since we need to
keep those names for backward compatibility, anyway.