GF/src is now for 2.9, and the new sources are in src-3.0 - keep it this way until the release of GF 3

src-3.0/GF/Parsing/FCFG/Range.hs

@@ -0,0 +1,50 @@
+---------------------------------------------------------------------
+-- |
+-- Maintainer  : Krasimir Angelov
+-- Stability   : (stable)
+-- Portability : (portable)
+--
+-- Definitions of ranges, and operations on ranges
+-----------------------------------------------------------------------------
+
+module GF.Parsing.FCFG.Range
+    ( RangeRec, Range(..), makeRange, concatRange, rangeEdge, edgeRange, minRange, maxRange,
+    ) where
+
+
+-- GF modules
+import GF.Formalism.Utilities
+import GF.Infra.PrintClass
+
+------------------------------------------------------------
+-- ranges as single pairs
+
+type RangeRec = [Range]
+
+data Range = Range {-# UNPACK #-} !Int {-# UNPACK #-} !Int
+	   | EmptyRange
+             deriving (Eq, Ord)
+
+makeRange :: Int -> Int -> Range
+makeRange = Range 
+
+concatRange :: Range -> Range -> [Range]
+concatRange EmptyRange  rng          = return rng
+concatRange rng         EmptyRange   = return rng
+concatRange (Range i j) (Range j' k) = [Range i k | j==j']
+
+rangeEdge :: a -> Range -> Edge a
+rangeEdge a (Range i j) = Edge i j a
+
+edgeRange :: Edge a -> Range
+edgeRange (Edge i j _) = Range i j
+
+minRange :: Range -> Int
+minRange (Range i j) = i
+
+maxRange :: Range -> Int
+maxRange (Range i j) = j
+
+instance Print Range where
+    prt (Range i j)  = "(" ++ show i ++ "-" ++ show j ++ ")"
+    prt (EmptyRange) = "(?)"