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syntax for inaccessible patterns in GF

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krasimir
2010-03-18 19:34:30 +00:00
parent dc0a84951f
commit 0c2944fa7f
11 changed files with 38 additions and 14 deletions
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28
src/runtime/haskell/PGF/Expr.hs
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@@ -1,5 +1,5 @@
module PGF.Expr(Tree, BindType(..), Expr(..), Literal(..), Patt(..), Equation(..),
readExpr, showExpr, pExpr, pBinds, ppExpr, ppPatt,
readExpr, showExpr, pExpr, pBinds, ppExpr, ppPatt, pattScope,
mkApp, unApp,
mkStr, unStr,
@@ -68,6 +68,7 @@ data Patt =
| PVar CId -- ^ variable
| PWild -- ^ wildcard
| PImplArg Patt -- ^ implicit argument in pattern
| PTilde Expr
deriving Show
-- | The equation is used to define lambda function as a sequence
@@ -223,14 +224,22 @@ ppExpr d scope (EVar i) = ppCId (scope !! i)
ppExpr d scope (ETyped e ty)= PP.char '<' PP.<> ppExpr 0 scope e PP.<+> PP.colon PP.<+> ppType 0 scope ty PP.<> PP.char '>'
ppExpr d scope (EImplArg e) = PP.braces (ppExpr 0 scope e)
ppPatt :: Int -> [CId] -> Patt -> ([CId],PP.Doc)
ppPatt d scope (PApp f ps) = let (scope',ds) = mapAccumL (ppPatt 2) scope ps
in (scope',ppParens (not (List.null ps) && d > 1) (ppCId f PP.<+> PP.hsep ds))
ppPatt d scope (PLit l) = (scope,ppLit l)
ppPatt d scope (PVar f) = (f:scope,ppCId f)
ppPatt d scope PWild = (scope,PP.char '_')
ppPatt d scope (PImplArg p) = let (scope',d) = ppPatt 0 scope p
in (scope',PP.braces d)
ppPatt :: Int -> [CId] -> Patt -> PP.Doc
ppPatt d scope (PApp f ps) = let ds = List.map (ppPatt 2 scope) ps
in ppParens (not (List.null ps) && d > 1) (ppCId f PP.<+> PP.hsep ds)
ppPatt d scope (PLit l) = ppLit l
ppPatt d scope (PVar f) = ppCId f
ppPatt d scope PWild = PP.char '_'
ppPatt d scope (PImplArg p) = PP.braces (ppPatt 0 scope p)
ppPatt d scope (PTilde e) = PP.char '~' PP.<> ppExpr 6 scope e
pattScope :: [CId] -> Patt -> [CId]
pattScope scope (PApp f ps) = foldl pattScope scope ps
pattScope scope (PLit l) = scope
pattScope scope (PVar f) = f:scope
pattScope scope PWild = scope
pattScope scope (PImplArg p) = pattScope scope p
pattScope scope (PTilde e) = scope
ppBind Explicit x = ppCId x
ppBind Implicit x = PP.braces (ppCId x)
@@ -362,5 +371,6 @@ match sig f eqs as0 =
tryMatch (PApp f1 ps1) (VApp f2 vs2 ) env | f1 == f2 = tryMatches eqs (ps1++ps) (vs2++as) res env
tryMatch (PLit l1 ) (VLit l2 ) env | l1 == l2 = tryMatches eqs ps as res env
tryMatch (PImplArg p ) (VImplArg v ) env = tryMatch p v env
tryMatch (PTilde _ ) (_ ) env = tryMatches eqs ps as res env
tryMatch _ _ env = match sig f eqs as0