syntactic 1.16.1 → 1.16.2

raw patch · 3 files changed

+17/−8 lines, 3 files

Files

• src/Language/Syntactic/Constructs/Binding.hs +2/−0
• src/Language/Syntactic/Sharing/SimpleCodeMotion.hs +14/−7
• syntactic.cabal +1/−1

@@ -10,6 +10,8 @@ import qualified Control.Monad.Identity as Monad import Control.Monad.Reader import Data.Ix+import Data.Set (Set)+import qualified Data.Set as Set import Data.Tree import Data.Typeable 

@@ -66,6 +66,8 @@     subst :: AST dom c -> AST dom c     subst (f :$ a) = subst f :$ substitute x y a     subst a = a+  -- Note: Since `codeMotion` only uses `substitute` to replace sub-expressions+  -- with fresh variables, there's no risk of capturing.  -- | Count the number of occurrences of a sub-expression count :: forall dom a b@@ -92,22 +94,27 @@         -- expression     } -independent :: PrjDict dom -> Env dom -> AST dom a -> Bool-independent pd env (Sym (prjVariable pd -> Just v)) = not (v `member` dependencies env)-independent pd env (f :$ a) = independent pd env f && independent pd env a-independent _ _ _ = True- isVariable :: PrjDict dom -> ASTF dom a -> Bool isVariable pd (Sym (prjVariable pd -> Just _)) = True isVariable pd _ = False +-- | Get the set of free variables in an expression+freeVars :: PrjDict dom -> AST dom sig -> Set VarId+freeVars pd (Sym var)+    | Just v <- prjVariable pd var = Set.singleton v+freeVars pd (Sym lam :$ body)+    | Just v <- prjLambda pd lam = Set.delete v (freeVars pd body)+freeVars pd (s :$ a) = Set.union (freeVars pd s) (freeVars pd a)+freeVars _ _ = Set.empty+ -- | Checks whether a sub-expression in a given environment can be lifted out liftable :: PrjDict dom -> Env dom -> ASTF dom a -> Bool-liftable pd env a = independent pd env a && not (isVariable pd a) && heuristic+liftable pd env a = independent && not (isVariable pd a) && heuristic     -- Lifting dependent expressions is semantically incorrect     -- Lifting variables would cause `codeMotion` to loop   where-    heuristic = inLambda env || (counter env (ASTE a) > 1)+   independent = Set.null $ Set.intersection (freeVars pd a) (dependencies env)+   heuristic   = inLambda env || (counter env (ASTE a) > 1)   

@@ -1,5 +1,5 @@ Name:           syntactic-Version:        1.16.1+Version:        1.16.2 Synopsis:       Generic abstract syntax, and utilities for embedded languages Description:    This library provides:                 .