3 Feb
2011
3 Feb
'11
3:28 a.m.
Navin Rustagi
It gives the error ERROR - Control stack overflow. I assume it is because of the lazy evaluation.
Yes, you're just building a tower of additions, and when evaluating this, you blow up the stack. You need to make sure to evaluate the tuple element each time, so instead of
case ys of 'A' -> (elf, els+1,elr,ell,elx)
write:
case ys of 'A' -> els `seq` (elf, els+1,elr,ell,elx)
(Strictly speaking this will only evaluate the previous value, but your tower of additions will now have maximum one floor) -k -- If I haven't seen further, it is by standing in the footprints of giants