samer@13: % scanl - scanl for cell arrays
samer@13: %
samer@13: % scanl :: 
samer@13: %    (S,X->S)   ~'scannning function',
samer@13: %    S          ~'initial value',
samer@13: %    {[N]->X}   ~'data to scan, sequence of length L'
samer@13: % -> {[N]->S}.
samer@13: function Y=scanl(f,y,X), Y=cscanl(f,y,X); end