Type: fit :: Int -> [a] -> Pattern Int -> Pattern a

The fit function takes a pattern of integer numbers, which are used to select values from the given list. What makes this a bit strange is that only a given number of values are selected each cycle. For example:

d1 $ sound (fit 3 ["bd", "sn", "arpy", "arpy:1", "casio"] "0 [~ 1] 2 1")

The above fits samples into the pattern by number, i.e. for the first cycle this will be "bd", "sn" and "arpy", giving the result "bd [~ sn] arpy sn" (note that we start counting at zero, so that 0 picks the first value). For the following cycle, the same is done again, but offset by the number given in the first parameter. In the above case it's 3, which is effectively added to all the numbers, giving "3 [~ 4] 5 4", giving giving the pattern "arpy:1 [~ casio] bd casio" (note that the list wraps round here, so 5 goes back to choose the first element in the list). The next cycle, 6 is added to all the numbers, then 9, and so on.

fit'

Type: fit' :: Time -> Int -> Pattern Int -> Pattern Int -> Pattern a -> Pattern a

fit' is a generalization of fit, where the list is instead constructed by using another integer pattern to slice up a given pattern. The first argument is the number of cycles of that latter pattern to use when slicing. It’s easier to understand this with a few examples:

d1 $ sound (fit' 1 2 "0 1" "1 0" "bd sn")

So what does this do? The first 1 just tells it to slice up a single cycle of "bd sn". The 2 tells it to select two values each cycle, just like the first argument to fit. The next pattern "0 1" is the “from” pattern which tells it how to slice, which in this case means "0" maps to "bd", and "1" maps to "sn". The next pattern "1 0" is the “to” pattern, which tells it how to rearrange those slices. So the final result is the pattern "sn bd".

A more useful example might be something like

d1 $ fit' 1 4 (run 4) "[0 3*2 2 1 0 3*2 2 [1*8 ~]]/2" $ chop 4 $ (sound "breaks152" # unit "c")

which uses chop to break a single sample into individual pieces, which fit' then puts into a list (using the run 4 pattern) and reassembles according to the complicated integer pattern.