[Freecats-Dev] language / database / integration

[Dave Simons]

Hi everyone

I've been following discussions as best I can and have a few thoughts on 
the matters mentioned. They might give you food for thought. Use or abuse 
them as you will.

1. Language
2. Database
3. Integration


1. Language

The question was raised about what alternative development environments 
there are, the current preferred one being Tcl/Tk.

As far as I know the only reasonable alternatives that will run on 
Windows/Mac/Linux/*BSD are Python, Perl, and Java.
Concerning toolkits, only Java Swing and Tk seem to fit the bill. Tk on its 
own is very a basic toolkit: the interface is always going to look a bit 
primitive compared with flashier toolkits like Qt, but if eye candy is 
what's wanted, there are
extensions (mega widgets) available from third party groups (still free 
software), though things start getting complex from a development point of 
view if you include these.

As for the language environment, Python has a Tkinter module which gives it 
access to the Tk toolkit and also a Python Mega Widget (PMW) library 
providing similar advanced widgets to its those of the Tcl extensions. I 
thought there might be a doubt about using PMW on Mac but the page below 
seems to allay those fears.

http://mail.python.org/pipermail/pythonmac-sig/2001-April/003386.html

Similarly, Perl has Perl/tk, though the mega widget position looks less 
clear. I don't personally like Perl (since
I'm not writing the programs you can take that with a pinch of salt :-) 
There are some real readability issues with
the language: many consider it a write-only language, difficult for anyone 
other than the author to maintain. Perl fans will argue otherwise but it's 
more of a religious argument.

Java is of course able to do everything you want on all these platforms and 
I wouldn't dismiss it lightly merely for philosophical reasons.** (see 
argument below) There are open source runtimes available, and if you don't 
like the language itself, there's always Jython, which lets you call all 
the Java features from a program written in Python. That leaves only the 
"problem" of the proprietary widgets. Well, they might be proprietary, but 
it doesn't seem to stop you using them where and how you want.

**Free software is a great movement but let's be pragmatic; unless you are 
a developer, there are only two main issues, interoperability and lock-in. 
And before everyone says "yes but we ARE developers" I'll reply "sure, but 
you're not writing
for developers." And let's face it, do you really want to change the source 
code of the language or toolkit you're using?


2. Database

From all the gossip I've heard, one of the fastest databases out there 
(and speed really is an issue in this application) is
berkely DB. http://www.sleepycat.com/products/index.shtml. It's a 
proprietary system but comes with the source code and is issued under a 
licence that bears an uncanny resemblance to some other GPL-compatible 
licences (you only pay if you don't want to use it in a closed-source 
application). Note, this is NOT an SQL database, but since we're looking at 
a very limited number of look-up scenarii rather than total flexibility I 
can't see this being an issue. A full native API is available for C, C++, 
Java, Tcl, Perl, and  Python. This is interesting: the languages mentioned 
have interfaces available for lots of databases, but you could hardly call 
them a _full_ API. Many of them boil down to just two commands: "connect" 
and "send query."

3. Integration

This is a serious issue and should be an important consideration when 
choosing the development platform. If you want to build, say, a 
Python/Tkinter application using mega widets, a database, some kind of XML 
parser, plus of course the
application, then you're including bits and pieces from all over the place. 
That might be OK for someone who's used to Linux or FreeBSD, but it's going 
to be disconcerting to your average layman who just wants to download the 
application and run it. It can be quite a challenge to produce a seamless 
package, but it really is important to do so otherwise the application is 
not going to get widespread use. Though you won't like me saying it (I 
don't even like saying it myself), Java wins hands down in this department.

Hope someone finds my ramblings useful.

Dave Simons