So....it basically does all the work for you?
Yep - and that is the problem. Compiler writes the program for you so often you have only very vague idea about what the program actually
does. Worse: sometimes your ideas and compiler ideas differ - and while Haskel gurantees that the produced result will be correct it does not guarantee that the algorithm implemented will be equal to your imagination (because it has no idea about your thought process, you know).
The end result is two-step:
First step: Euphoria. You write 1'000 lines of code, it works (and does the computations which require 10'000 lines of code in more traditional language), everyone is happy.
Second step: Disillusionment. You change some small definition... and everything blows up: instead of producing the result in seconds and using 100MB of RAM (where traditional language will use 10MB) it chews 10GB or RAM and works for a few hours. At this stage you have three choices:
1. Spend few weeks trying to pull the execution model from haskel compiler (to compare it with the model produced by your imagination).
2. Spend month or two rewriting everything in C++ or Java (where you actually control the execution).
3. Give up and just wait till the program will produce something (quite acceptable approach if you only need to run the program once or twice).
Haskell is quite nice for prototyping, but to write robust production systems using it you need years of practice. Few people reach this stage (I'm not among them).
