tuples

I am searching some optimized datatypes for "observations-variables" table in Matlab, that can be fast and easily accessed by columns (through variables) and by rows (through observations). Here is сomparison of existing Matlab datatypes: Matrix is very fast, hovewer, it has no built-in indexing labels/enumerations for its dimensions, and you can't always remember variable name by column index. Table has very bad performance, especially when reading individual rows/columns in a for loop (I suppose it runs some slow convertion methods, and is designed to be more Excel-like). Scalar structure

Consider, for example, squares = *map((2).__rpow__, range(5)), squares # (0, 1, 4, 9, 16) *squares, = map((2).__rpow__, range(5)) squares # [0, 1, 4, 9, 16] So, all else being equal we get a list when splatting on the lhs and a tuple when splatting on the rhs. Why? Is this by design, and if yes, what's the rationale? Or, if not, are there any technical reasons? Or is this just how it is, no particular reason? The fact that you get a tuple on the RHS has nothing to do with the splat. The splat just unpacks your map iterator. What you unpack it into is decided by the fact that you've used tuple

Given two lists, [a, b] and [c, d] , I'd like to get the following result: [(a,c), (a,d), (b,c), (b,d)] How can I do this in Haskell? Is there a built-in function for this, or should I implement one myself? [ (x,y) | x<-[a,b], y<-[c,d] ] This doesn't really require any further explanation, does it? jub0bs Applicative style all the way! λ> :m + Control.Applicative λ> (,) <$> ['a','b'] <*> ['c','d'] [('a','c'),('a','d'),('b','c'),('b','d')] (I've eschewed any String syntactic sugar above, in order to stay close to your example.) For information, (,) is special syntax for a function that takes