signals

newtype Signal y = Signal { sig_vec :: SignalBase.SigVec Y }
    -- The Eq instance is only for tests, since it may be quite expensive on
    -- a real signal.
    deriving (Eq)

type X = SignalBase.X
type Y = Double
instance SignalBase.Signal Y

-- | This is the type of performer-interpreted controls that go into the
-- event's control map.
type Control = Signal ControlSig
data ControlSig

... -- many more
instance Storable.Storable (X, Y) where
    ...

at, at_linear :: X → Signal y → Y
sig_add, sig_subtract, sig_multiply :: Control → Control → Control
integrate :: X → Tempo → Warp
compose :: Warp → Warp → Warp

• Fun with phantom types!
• Not lazy yet :(
• Space and simplicity trade-offs: initially linear (x, y) segments, currently (x, y) flat segments, except Warp which is a constant sampling rate.
• Variable sampling rate: accurate (infinite sampling rate), space efficient (many flat segments).
• Constant sampling rate: simple implementation (therefore fast, no resampling), space efficient for dense signals. Also 1 minute of 1024hz signal is only 480k, 240k for floats. Intermediate signals can be GCed as they are used (once lazy), but the original ones are retained for multiple passes.
• Possible compromise: blocks with constant sampling rate but each with its own rate.