Retrieving patterns from custom Control Maps

Questions and Answers
#1

Hi! I'm trying to retrieve a Pattern from a ControlPattern or ControlMap function, so that I can use it somewhere else, but I'm a bit lost.

-- Example 1
let var = mI "var"
in d1
  $ s "bd*4"
  # var "1 2 3 4"
  # up (pI "var" 0)

-- Example 2
let myshift = mF "myshift"
in d1
  $ note ("0 4 7 12"  |+ (pF "myshift"))
  # s "superpiano"
  # myshift "1 2 3 4"

I went through @bgold's boot.tidal as reference, but I don't understand how to properly use pF, mF, pI, mI and query or what are their limitations and alternatives to acheive this. Is there a way to do this?

#2 
import qualified Data.Map as M
:set +t

cpat = s "superpiano" >| n "[e d f g]"
cpat :: Pattern ControlMap

maybe 0 fvalue <$> M.lookup "n" <$> cpat
(0>¼)|4.0
(¼>½)|2.0
(½>¾)|5.0
(¾>1)|7.0
it :: Pattern Double

functions used:

pF :: String -> Pattern Double -> ControlPattern
  	-- Defined in ‘Sound.Tidal.Params’
data Value = ... | VF {fvalue :: Double} | ...
  	-- Defined in ‘Sound.Tidal.Pattern’
M.lookup :: Ord k => k -> M.Map k a -> Maybe a
  	-- Defined in ‘Data.Map.Internal’
maybe :: b -> (a -> b) -> Maybe a -> b 	-- Defined in ‘Data.Maybe’
(<$>) :: Functor f => (a -> b) -> f a -> f b
  	-- Defined in ‘Data.Functor’

the last one is used at instance f = Pattern

1 Like
#3

Took me a while to understand what this code is doing (my haskell is not too good)
Thanks a lot for putting this together, it's been super helpful already