parser tweaks

qtys and dims don't allow useless parens any more. everything else
should be the same

lib/Quox/Parser/Parser.idr

@@ -18,8 +18,7 @@ Grammar = Core.Grammar () Token
 
 export
 res : (str : String) -> (0 _ : IsReserved str) => Grammar True ()
-res str = terminal "expecting \"\{str}\"" $
-  \x => guard $ x == Reserved str
+res str = terminal "expecting \"\{str}\"" $ guard . (== Reserved str)
 
 export
 resC : (str : String) -> (0 _ : IsReserved str) => Grammar True ()
@@ -107,30 +106,41 @@ bname = Nothing <$ res "_"
     <|> [|Just baseName|]
 
 export
-zeroOne : (zero, one : a) -> Grammar True a
-zeroOne zero one = terminal "expecting zero or one" $
-  \case Nat 0 => Just zero; Nat 1 => Just one; _ => Nothing
+dimConst : Grammar True DimConst
+dimConst = terminal "expecting 0 or 1" $
+  \case Nat 0 => Just Zero; Nat 1 => Just One; _ => Nothing
 
-
-export covering
+export
 qty : Grammar True PQty
-qty = zeroOne Zero One
-  <|> Any <$ res "ω"
-  <|> parens qty
+qty = terminal "expecting quantity" $
+  \case Nat 0 => Just Zero; Nat 1 => Just One; Reserved "ω" => Just Any
+        _ => Nothing
+
+
+public export
+AllReserved : List (a, String) -> Type
+AllReserved = foldr (\x, ps => (IsReserved $ snd x, ps)) ()
+
+export
+symbols : (lst : List (a, String)) -> (0 _ : AllReserved lst) =>
+          Grammar True a
+symbols []                 = fail "no symbols found"
+symbols ((x, str) :: rest) = x <$ res str <|> symbols rest
+
+export
+symbolsC : (lst : List (a, String)) -> (0 _ : AllReserved lst) =>
+           Grammar True a
+symbolsC lst = symbols lst <* commit
+
 
 private covering
 qtys : Grammar False (List PQty)
 qtys = option [] [|toList $ some qty <* res "."|]
 
-export
-dimConst : Grammar True DimConst
-dimConst = zeroOne Zero One
 
-export covering
+export
 dim : Grammar True PDim
-dim = [|V baseName|]
-  <|> [|K dimConst|]
-  <|> parens dim
+dim = [|V baseName|] <|> [|K dimConst|]
 
 private
 0 PBinderHead : Nat -> Type
@@ -154,9 +164,9 @@ makeSig : MakeBinder 0
 makeSig = ("×", \([], x, s) => Sig x s)
 
 private
-makeBinder : {m, n : Nat} -> MakeBinder m -> PBinderHead n -> PTerm ->
+makeBinder : (m ** PBinderHead m) -> (n ** MakeBinder n) -> PTerm ->
              Grammar False PTerm
-makeBinder (str, f) h t =
+makeBinder (m ** h) (n ** (str, f)) t =
   case decEq m n of
     Yes Refl => pure $ f h t
     No  _    =>
@@ -165,18 +175,15 @@ makeBinder (str, f) h t =
 
 private
 binderInfix : Grammar True (n ** MakeBinder n)
-binderInfix = res "→" $> (1 ** makePi)
-          <|> res "×" $> (0 ** makeSig)
+binderInfix = symbols [((1 ** makePi), "→"), ((0 ** makeSig), "×")]
 
 private
 lamIntro : Grammar True (BName -> PTerm -> PTerm)
-lamIntro = Lam  <$ resC "λ"
-       <|> DLam <$ resC "δ"
+lamIntro = symbolsC [(Lam, "λ"), (DLam, "δ")]
 
 private covering
 caseIntro : Grammar True PQty
-caseIntro = resC "case1" $> One
-        <|> resC "caseω" $> Any
+caseIntro = symbols [(One, "case1"), (Any, "caseω")]
         <|> resC "case" *> qty <* resC "."
 
 private
@@ -186,13 +193,7 @@ optNameBinder = [|join $ optional $ bname <* darr|]
 mutual
   export covering
   term : Grammar True PTerm
-  term = lamTerm
-     <|> caseTerm
-     <|> bindTerm
-     <|> [|annotate infixEqTerm (optional $ resC "∷" *> term)|]
-  where
-    annotate : PTerm -> Maybe PTerm -> PTerm
-    annotate s a = maybe s (s :#) a
+  term = lamTerm <|> caseTerm <|> bindTerm <|> annTerm
 
   private covering
   lamTerm : Grammar True PTerm
@@ -203,23 +204,25 @@ mutual
   caseTerm =
     [|Case caseIntro term
            (resC "return" *> optBinderTerm)
-           (resC "of"     *> braces caseBody)|]
+           (resC "of"     *> caseBody)|]
 
   private covering
-  caseBody : Grammar False PCaseBody
-  caseBody = [|CasePair (pairPat <* darr) (term <* optSemi)|]
-         <|> [|CaseEnum $ semiSep [|MkPair tag (darr *> term)|]|]
+  caseBody : Grammar True PCaseBody
+  caseBody = braces $
+        [|CasePair (pairPat <* darr) (term <* optSemi)|]
+    <|> [|CaseEnum $ semiSep [|MkPair tag (darr *> term)|]|]
   where
-    optSemi = ignore $ optional $ res ";"
+    optSemi = optional $ res ";"
     pairPat = parens [|MkPair bname (resC "," *> bname)|]
 
   private covering
   bindTerm : Grammar True PTerm
-  bindTerm = do
-    bnd <- binderHead
-    inf <- binderInfix
-    body <- term
-    makeBinder (snd inf) (snd bnd) body
+  bindTerm = join [|makeBinder binderHead binderInfix term|]
+
+  private covering
+  annTerm : Grammar True PTerm
+  annTerm = [|annotate infixEqTerm (optional $ resC "∷" *> term)|]
+  where annotate s a = maybe s (s :#) a
 
   private covering
   infixEqTerm : Grammar True PTerm
@@ -241,8 +244,7 @@ mutual
     data PArg = TermArg PTerm | DimArg PDim
 
     appArg : Grammar True PArg
-    appArg = [|DimArg $ resC "@" *> dim|]
-         <|> [|TermArg aTerm|]
+    appArg = [|DimArg $ resC "@" *> dim|] <|> [|TermArg aTerm|]
 
     apply : PTerm -> List PArg -> PTerm
     apply = foldl apply1 where
@@ -261,10 +263,9 @@ mutual
   private covering
   binderHead : Grammar True (n ** PBinderHead n)
   binderHead = parens {commit = False} $ do
-    qs <- [|toVect qtys|]
+    qs   <- [|toVect qtys|]
     name <- bname
-    resC ":"
-    ty <- term
+    ty   <- resC ":" *> term
     pure (qs.fst ** (qs.snd, name, ty))
 
   private covering
@@ -274,8 +275,7 @@ mutual
 
 export covering
 defIntro : Grammar True PQty
-defIntro = Zero <$ resC "def0"
-       <|> Any  <$ resC "defω"
+defIntro = symbols [(Zero, "def0"), (Any, "defω")]
        <|> resC "def" *> option Any (qty <* resC ".")
 
 export covering

tests/Tests/Parser.idr

@@ -70,8 +70,7 @@ tests = "parser" :- [
   "dimensions" :- [
     parsesAs dim "0" (K Zero),
     parsesAs dim "1" (K One),
-    parsesAs dim "ι" (V "ι"),
-    parsesAs dim "(0)" (K Zero),
+    parsesAs dim "𝑖" (V "𝑖"),
     parseFails dim "M.x",
     parseFails dim "_"
   ],
@@ -81,7 +80,6 @@ tests = "parser" :- [
     parsesAs qty "1" One,
     parsesAs qty "ω" Any,
     parsesAs qty "#" Any,
-    parsesAs qty "(#)" Any,
     parseFails qty "anythingElse",
     parseFails qty "_"
   ],