Wow ... thanks Serguey .... that gets rid of DatatypeContexts as well!
Regards,
Kashyap
On Mon, Apr 1, 2013 at 9:12 PM, Serguey Zefirov
You have fixed the type of list by move RAX RAX. Now it has type Instruction SNDREG SNDREG
Make your Instruction a GADT and require that MOV should have appropriate constraints:
{-# LANGUAGE DatatypeContexts, GADTs #-}
data SREG = RIP data DREG = RBX data SNDREG = RAX
data Instruction where MOV :: (Source s, Destination d) => s -> d -> Instruction
class Source a class Destination a
instance Source SREG instance Source SNDREG
instance Destination DREG instance Destination SNDREG
move :: (Source s, Destination d) => s -> d -> Instruction move s d = MOV s d
hello = [move RAX RAX, move RAX RAX]
hello2 = [move RAX RAX, move RAX RBX] -- this is still not allowed.
2013/4/1 C K Kashyap
Hi Cafe, I am trying to embed x86 assembly in Haskell. I'd like the EDSL to not allow invalid movements into registers - for example, should not allow moving into RIP. I was not able to get it to work. I ended up using DataTypeContexts - which is considered misfeature anyway. I was wondering if I could get some suggestions.
{-# LANGUAGE DatatypeContexts #-}
data SREG = RIP data DREG = RBX data SNDREG = RAX
data (Source s, Destination d) => Instruction s d = MOV s d
class Source a class Destination a
instance Source SREG instance Source SNDREG
instance Destination DREG instance Destination SNDREG
move :: (Source s, Destination d) => s -> d -> Instruction s d move s d = MOV s d
hello = [move RAX RAX, move RAX RAX]
hello = [move RAX RAX, move RAX RBX] -- this is still not allowed.
Regards, Kashyap
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