parser-combinators 1.0.3 → 1.1.0

raw patch · 3 files changed

+41/−9 lines, 3 files

Files

• CHANGELOG.md +5/−0
• Control/Monad/Combinators/Expr.hs +35/−8
• parser-combinators.cabal +1/−1

@@ -1,3 +1,8 @@+## Parser combinators 1.1.0++* Added support for ternary operators; see `TernR` in+    `Control.Monad.Combinators.Expr`.+ ## Parser combinators 1.0.3  * Dropped support for GHC 7.10.

@@ -30,6 +30,18 @@   | InfixR  (m (a -> a -> a)) -- ^ Right-associative infix   | Prefix  (m (a -> a))      -- ^ Prefix   | Postfix (m (a -> a))      -- ^ Postfix+  | TernR   (m (m (a -> a -> a -> a)))+    -- ^ Right-associative ternary. Right-associative means that+    -- @a ? b : d ? e : f@ parsed as+    -- @a ? b : (d ? e : f)@ and not as @(a ? b : d) ? e : f@.+    --+    -- The outer monadic action parses the first separator (e.g. @?@) and+    -- returns an action (of type @m (a -> a -> a -> a)@) that parses the+    -- second separator (e.g. @:@).+    --+    -- Example usage:+    --+    -- >>> TernR ((If <$ char ':') <$ char '?')  -- | @'makeExprParser' term table@ builds an expression parser for terms -- @term@ with operators from @table@, taking the associativity and@@ -89,13 +101,14 @@  addPrecLevel :: MonadPlus m => m a -> [Operator m a] -> m a addPrecLevel term ops =-  term' >>= \x -> choice [ras' x, las' x, nas' x, return x]+  term' >>= \x -> choice [ras' x, las' x, nas' x, tern' x, return x]   where-    (ras, las, nas, prefix, postfix) = foldr splitOp ([],[],[],[],[]) ops+    (ras, las, nas, prefix, postfix, tern) = foldr splitOp ([],[],[],[],[],[]) ops     term' = pTerm (choice prefix) term (choice postfix)     ras'  = pInfixR (choice ras) term'     las'  = pInfixL (choice las) term'     nas'  = pInfixN (choice nas) term'+    tern' = pTernR  (choice tern) term' {-# INLINEABLE addPrecLevel #-}  -- | @pTerm prefix term postfix@ parses a @term@ surrounded by optional@@ -144,19 +157,33 @@   return $ f x y {-# INLINE pInfixR #-} +-- | Parse the first separator of a ternary operator++pTernR :: MonadPlus m => m (m (a -> a -> a -> a)) -> m a -> a -> m a+pTernR sep1 p x = do+  sep2 <- sep1+  y <- p >>= \r -> pTernR sep1 p r `mplus` return r+  f <- sep2+  z <- p >>= \r -> pTernR sep1 p r `mplus` return r+  return $ f x y z+{-# INLINE pTernR #-}+ type Batch m a =   ( [m (a -> a -> a)]   , [m (a -> a -> a)]   , [m (a -> a -> a)]   , [m (a -> a)]-  , [m (a -> a)] )+  , [m (a -> a)]+  , [m (m (a -> a -> a -> a))]+  )  -- | A helper to separate various operators (binary, unary, and according to -- associativity) and return them in a tuple.  splitOp :: Operator m a -> Batch m a -> Batch m a-splitOp (InfixR  op) (r, l, n, pre, post) = (op:r, l, n, pre, post)-splitOp (InfixL  op) (r, l, n, pre, post) = (r, op:l, n, pre, post)-splitOp (InfixN  op) (r, l, n, pre, post) = (r, l, op:n, pre, post)-splitOp (Prefix  op) (r, l, n, pre, post) = (r, l, n, op:pre, post)-splitOp (Postfix op) (r, l, n, pre, post) = (r, l, n, pre, op:post)+splitOp (InfixR  op) (r, l, n, pre, post, tern) = (op:r, l, n, pre, post, tern)+splitOp (InfixL  op) (r, l, n, pre, post, tern) = (r, op:l, n, pre, post, tern)+splitOp (InfixN  op) (r, l, n, pre, post, tern) = (r, l, op:n, pre, post, tern)+splitOp (Prefix  op) (r, l, n, pre, post, tern) = (r, l, n, op:pre, post, tern)+splitOp (Postfix op) (r, l, n, pre, post, tern) = (r, l, n, pre, op:post, tern)+splitOp (TernR   op) (r, l, n, pre, post, tern) = (r, l, n, pre, post, op:tern)

@@ -1,5 +1,5 @@ name:                 parser-combinators-version:              1.0.3+version:              1.1.0 cabal-version:        1.18 tested-with:          GHC==8.0.2, GHC==8.2.2, GHC==8.4.4, GHC==8.6.5 license:              BSD3