Friday, April 07, 2006

Interactivity in Programming

One theme that I keep coming back to is interactivity. As much as possible your programming tools should let you affect what is going on at any moment.

A neat new feature in the upcoming Liberty BASIC 5 that I demonstrated in New York is a more interactive debugging capability. Just as before you can start a program in the debugger from the editor, of course. One really cool new thing that you can do is just run the program without starting it in a debugger. You can then at any time decide that you want to debug the program. Just bring any window of the program to the top and break into it. A debugger will open on that program. You can examine variables, or if you like click on a line of code where you want to stop in the debugger and click on the Run To button. Then use the program and when that line of code is reached, the debugger will stop and highlight that line of code and you can see the variables. Then single step through the code, or just click the Run button to proceed full speed.

This is the sort of thing that I'm trying to provide that will bring back the interactivity of classic BASIC, which is one of it's more important features. Most newer programming languages (including most versions of BASIC) are pure compilers and do not let you stop a program in the middle are restart it.