Hey Ovid,

I am also re-writing someone elses code. In my case its an open source project that has been rewritten and evolved inr 3 generations of code, without ever using strict or documenting. Very very nasty now.

I would tell you that in my opinion

1) use strict.. This may seem like alot of code rewriting at first... but its worth it. You will then know all the actual variables defined within the main loop, while also identifying which values are imported from modules. If this has been done already ... hoorah for good intentions on there half.

2)Begin to trace the actual execution of your program. What sub gets called first.. what does it call.. what modules it is dependent on. This map is essential for a complete understanding of what the old program does and how modifications will affect it, as well as the best place to put your modifications.

3) Once you have this you can begin to create a standard way to pass data between the modules and work from the main routine outwards to the subroutines as they are called. This way when you break it, and you will, you will know at what logical point in the execution you are in.

You should defiently do this in a test environment so that current users will not bitch too much. In addition to this you should take care of the documenation you described earlier. My advice only relates to a rewrite of the code, not starting from scratch.. so I hope it gave you some value. It's working for me so far.

Dave

In reply to Re: Rewriting a large code base by Zapawork
in thread Rewriting a large code base by Ovid

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