Friday, January 14, 2005

Exploratory Programming and BASIC

One idea that hasn't been written much about lately in the computer press is "exploratory programming." This idea was very popular about a decade ago and it refers to powerful programming tools that make it easy and quick to try out different ideas. Smalltalk is one of the best examples of an exploratory programming environment. Smalltalk lets you make objects that "live" in your programming IDE and then you can play with them to see what happens. You don't need to compile a program at all to build software. Why does this matter? Exploratory programming helps make programming easier, more fun, and less intimidating. You can play around with little pieces of the program you're trying to create until you feel that you understand it well enough to put it all together.

Okay, what does Smalltalk have to do with BASIC? I'm glad you asked. :-) BASIC was originally conceived as an exploratory programming tool. BASIC has an interpreter loop, just like Smalltalk. Write a little code, use RUN to execute just a piece of your program if you like. Stop a running program, check the value of variables and change them. Rewrite just a line of code if you like. Restart the program. Execute code without even adding it to your program, straight from the command line. Most BASICs on home computers would let you play with the hardware, from graphics to audio to devices connected to an I/O port, again straight from the command line. You were free to explore.

Sadly BASIC is not like this anymore. Almost all BASIC language software today compiles to a program that cannot stopped, tweaked, modifed and restarted. Even our own Liberty BASIC http://www.libertybasic.com are like this (except that Liberty BASIC you can evaluate code in the debugger and by using the eval() function).

We are working on a new BASIC to bring exploratory programming back. This will not be an old fashioned line numbered interpreter. This new BASIC will provide a workbench where you can make changes to running programs, and where you can try out small or large BASIC snippets just to see what they do.

More information coming...

2 comments:

Carl Gundel said...

Hi Tom!

What did you think of my post about exploratory programming?

Carl Gundel said...

Thanks Tom. :-) Exploratory programming is not a panacea, but it is good for a few things:

-Learning to program
-Building very complex software systems a piece at a time
-Debugging when a bug only shows up after several minutes of use
-Modifying a running system without restarting it

I'm not planning to build an old style BASIC interpreter. What I'm working on is going to be very modern, and very easy to use.