-- maybe, and returns the current one.
f col_idx (q,r) idx _ -- ignore the current element
| idx <= col_idx = (q,r) -- leave it alone
| otherwise = (q*rotator, (transpose rotator)*r)
where
y = r !!! (idx, col_idx)
-- maybe, and returns the current one.
f col_idx (q,r) idx _ -- ignore the current element
| idx <= col_idx = (q,r) -- leave it alone
| otherwise = (q*rotator, (transpose rotator)*r)
where
y = r !!! (idx, col_idx)