First, due to what journalists call "full disclosure", I should mention
that I make a living as a consultant who uses Racket almost exclusively
now, and will probably write a Racket software engineering book soon,
and so I have a conflict of interest in encouraging new projects to use
Racket. :)
gonzalo diethelm wrote at 08/19/2011 06:07 PM:
So let me get to my point before I bore everyone here to death: can my
desire be realistically fulfilled? Can Scheme (Racket) be used for a
more "enterprise-y" project (console app, GUI app, web app, whatever,
accessing data from any RDBMS in transactional ways) where I will have
a team of developers working on separate parts of the system at the
same time?
Yes. One of my consulting clients has a large code base (order of
magnitude larger than the Racket/DrRacket distribution and its standard
libraries), in production for years, making heavy use of PostgreSQL.
Regarding project management, most of the usual practices apply, and
there are only a few differences with Racket that I see, and you can
predict what I'll say, but I will spell out for the larger audience here:
* The first biggest difference with Racket that you *must* consider is
what, at least in the US, industry used to call "nobody ever got fired
for buying IBM": any time you use something that not everyone considers
a "safe" choice, that is a political vulnerability, so you need to have
the political power to choose. (This is not exclusive to Racket.
Separate from any technical considerations, choosing Python is
politically risky in some environments, and even Java can be politically
risky unless you're doing a routine intranet Java enterprise app and
using a "safe" framework. I think the difference here is "Why are you
using Java/Python when I think it is unsuitable for this purpose," vs.
"Why are you using something on which I do not already have an opinion?" :)
* The second biggest difference with Racket that you *must* consider is
simply that usually project team members will not come to the project
knowing Racket like they "know" Java. This can be mitigated, and the
learning cure might well be "in the noise" if you need and have smart
developers on a substantial project.
* Then, as you know, there are advantages of Racket that you *may*
consider, which are linguistic, like the productivity and
maintainability leaps you might get when a team member makes DSLs that
are used by multiple other team members.
* You might also find sometimes that there's a library for Java that
does something you need, but you can't find a similar library for
Racket. This situation has improved a lot in the last few years, plus
there is now an FFI for easily calling C libraries. But eventually you
will encounter this situation, so be prepared to bang out that bit of
functionality (perhaps much better than the Java library does) after
first asking on the Racket email list to see if anyone else has such
code or knows an easy and good way to do it. This downside to this
situation might be more political than practical, if it's easy for you
to get the same functionality, but you'll have to explain to management
that the project is still winning with Racket, even if in this case you
did not have a library that a Java programmer would've.
Which brings me to my second question: can Scheme (Racket) be used to
develop all these different kinds of applications (console, GUI,
etc.)? Can anybody point me to real life examples of each type of
application developed with Scheme (Racket)?
DrRacket is a good example of a complicated GUI app that is used in
production.
Racket ships with a few console apps that are implemented in Racket.
Close to 10 years ago, I had a long-running console app in Racket that
was a specialized Web spider, and I also occasionally write utility
scripts as console apps. I think people write console apps frequently,
without considering them noteworthy.
The server apps in Racket tend to be non-public, because they are for
internal use of an enterprise, or for competitive or other reasons. I
believe that the PLaneT server is implemented in Racket, and it is public.
[In fact, I specifically came to Racket after having had a grand
vision of being able to develop all the components for a web app (SQL
to access the DB, business logic, HTML for presentation, CSS for
styling, JS for interactivity, even XML for configuration) using a
single unified language (or many small separate DSLs based on a single
language) and I have been kind of surprised at not finding this idea
fleshed out anywhere as a framework, library, module, etc.]
Yes, I have a client who has credited Racket's utility for SXML
processing and dynamic programming with being a strategic advantage.
There is another company down the street from me here that Google
bought, after they used another Lisp dialect to implement what in the
past had only been done with mainframes (and to interoperate with the
very complicated legacy mainframe network). They credit the DSL
capabilities of Lisps with being crucial to being able to do this at all
in a timely manner. (They also credit using a Lisp with being able to
attract a much better talent pool than they would've otherwise.)
if Scheme is the be-all and end-all of programming languages,
Before we go further, Racket is Racket, not Scheme. As soon as we start
saying Scheme, people start getting confused. :)
When people start talking about why does industry currently use the
technologies it does, people identify and speculate on many reasons.
Some of the reasons concern pragmatism and accidents of history, and
sometimes people are very critical about the state of current practice.
I think you'll find with Racket is that it's been a well-kept secret for
a decade, up until this last year, around the time when the name was
changed and it started to get noticed by more people. Many of the
people who stumbled upon Racket earlier ended up doing
industrial-strength app development in Racket, but on apps for use by
university students and schoolchildren, which is why I suggest looking
at DrRacket as a good example of an app developed in Racket. I think
we'll start seeing more publicly-accessible projects using Racket now.
FWIW, I have a background in mission-critical software engineering and
methodology, and, like you, did real development in C, then C++, then
Java, and various other languages in there (Perl, Smalltalk, Python,
Common Lisp, 4GLs, more obscure ones...), until I gravitated towards
Racket. I decided on Racket for the greater agility and sophistication
of the core language, and for the smart developer community.
Since you asked, I don't think anyone has yet invented the be-all and
end-all of programming language platforms, but Racket is the current
all-around best I can think of for most modern app development purposes
that are not externally constrained to use Java. (There is even a
project to adapt it for embedded systems.) The other platform that came
close for me, linguistically, is Haskell, but I think Racket wins for
DSLs and a few other reasons.
Another, smaller, advantage over Haskell: I can take an industry
programmer who used Pascal once in school, sit them in front of Racket
and have them ready to start being productive with other people's
libraries by the end of the day, treating Racket as only "a better
Pascal, with parentheses, plus some code patterns I've I'm using without
fully understanding". They can then learn idiomatic Racket, how to make
their own DSLs, and functional programming precepts incrementally as
they work, over the course of months. But sitting that same programmer
in front of Haskell... would be much more difficult.
--
http://www.neilvandyke.org/
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