1 module FlattenTypes where
4 import Data.Traversable
5 import qualified Data.Foldable as Foldable
6 import qualified Control.Monad.State as State
13 -- | A signal identifier
16 -- | A map of a Haskell value to signal ids
17 type SignalMap = HsValueMap SignalId
19 -- | A state identifier
22 -- | How is a given (single) value in a function's type (ie, argument or
23 -- return value) used?
25 Port -- ^ Use it as a port (input or output)
26 | State StateId -- ^ Use it as state (input or output). The int is used to
27 -- match input state to output state.
28 | HighOrder { -- ^ Use it as a high order function input
29 hoName :: String, -- ^ Which function is passed in?
30 hoArgs :: [HsUseMap] -- ^ Which arguments are already applied? This
31 -- ^ map should only contain Port and other
34 deriving (Show, Eq, Ord)
36 -- | Is this HsValueUse a state use?
37 isStateUse :: HsValueUse -> Bool
38 isStateUse (State _) = True
41 -- | A map from a Haskell value to the use of each single value
42 type HsUseMap = HsValueMap HsValueUse
44 -- | Builds a HsUseMap with the same structure has the given HsValueMap in
45 -- which all the Single elements are marked as State, with increasing state
47 useAsState :: HsValueMap a -> HsUseMap
51 -- Traverse the existing map, resulting in a function that maps an initial
52 -- state number to the final state number and the new map
53 PassState f = traverse asState map
54 -- Run this function to get the new map
56 -- This function maps each element to a State with a unique number, by
57 -- incrementing the state count.
58 asState x = PassState (\s -> (s+1, State s))
60 -- | Builds a HsUseMap with the same structure has the given HsValueMap in
61 -- which all the Single elements are marked as Port.
62 useAsPort :: HsValueMap a -> HsUseMap
63 useAsPort map = fmap (\x -> Port) map
65 -- | A Haskell function with a specific signature. The signature defines what
66 -- use the arguments and return value of the function get.
67 data HsFunction = HsFunction {
69 hsFuncArgs :: [HsUseMap],
71 } deriving (Show, Eq, Ord)
73 hasState :: HsFunction -> Bool
75 any (Foldable.any isStateUse) (hsFuncArgs hsfunc)
76 || Foldable.any isStateUse (hsFuncRes hsfunc)
78 -- | A flattened function application
80 appFunc :: HsFunction,
81 appArgs :: [SignalMap],
85 -- | A conditional signal definition
86 data CondDef = CondDef {
93 -- | How is a given signal used in the resulting VHDL?
95 SigPortIn -- | Use as an input port
96 | SigPortOut -- | Use as an input port
97 | SigInternal -- | Use as an internal signal
98 | SigStateOld StateId -- | Use as the current internal state
99 | SigStateNew StateId -- | Use as the new internal state
100 | SigSubState -- | Do not use, state variable is used in a subcircuit
102 -- | Is this a port signal use?
103 isPortSigUse :: SigUse -> Bool
104 isPortSigUse SigPortIn = True
105 isPortSigUse SigPortOut = True
106 isPortSigUse _ = False
108 -- | Is this a state signal use? Returns false for substate.
109 isStateSigUse :: SigUse -> Bool
110 isStateSigUse (SigStateOld _) = True
111 isStateSigUse (SigStateNew _) = True
112 isStateSigUse _ = False
114 -- | Is this an internal signal use?
115 isInternalSigUse :: SigUse -> Bool
116 isInternalSigUse SigInternal = True
117 isInternalSigUse _ = False
119 -- | Information on a signal definition
120 data SignalInfo = SignalInfo {
121 sigName :: Maybe String,
126 -- | A flattened function
127 data FlatFunction = FlatFunction {
128 flat_args :: [SignalMap],
129 flat_res :: SignalMap,
131 flat_conds :: [CondDef],
132 flat_sigs :: [(SignalId, SignalInfo)]
135 -- | Lookup a given signal id in a signal map, and return the associated
136 -- SignalInfo. Errors out if the signal was not found.
137 signalInfo :: [(SignalId, SignalInfo)] -> SignalId -> SignalInfo
138 signalInfo sigs id = Maybe.fromJust $ lookup id sigs
140 -- | A list of binds in effect at a particular point of evaluation
142 CoreBndr, -- ^ The bind name
143 Either -- ^ The bind value which is either
147 HsValueUse, -- ^ or a HighOrder function
148 [SignalId] -- ^ With these signals already applied to it
152 -- | The state during the flattening of a single function
153 type FlattenState = State.State ([FApp], [CondDef], [(SignalId, SignalInfo)], SignalId)
155 -- | Add an application to the current FlattenState
156 addApp :: (FApp) -> FlattenState ()
158 (apps, conds, sigs, n) <- State.get
159 State.put (a:apps, conds, sigs, n)
161 -- | Add a conditional definition to the current FlattenState
162 addCondDef :: (CondDef) -> FlattenState ()
164 (apps, conds, sigs, n) <- State.get
165 State.put (apps, c:conds, sigs, n)
167 -- | Generates a new signal id, which is unique within the current flattening.
168 genSignalId :: SigUse -> Type.Type -> FlattenState SignalId
169 genSignalId use ty = do
170 (apps, conds, sigs, n) <- State.get
171 -- Generate a new numbered but unnamed signal
172 let s = (n, SignalInfo Nothing use ty)
173 State.put (apps, conds, s:sigs, n+1)