[project @ 2000-03-23 17:45:17 by simonpj]

[ghc-hetmet.git] / ghc / compiler / utils / Maybes.lhs

diff --git a/ghc/compiler/utils/Maybes.lhs b/ghc/compiler/utils/Maybes.lhs
index 2f6118f..6dd9251 100644 (file)
--- a/ghc/compiler/utils/Maybes.lhs
+++ b/ghc/compiler/utils/Maybes.lhs
@@ -5,7 +5,7 @@
 
 \begin{code}
 module Maybes (
---     Maybe(..), -- no, it's in 1.3
+       Maybe2(..), Maybe3(..),
        MaybeErr(..),
 
        orElse, 
@@ -38,6 +38,18 @@ infixr 4 `orElse`
 
 %************************************************************************
 %*                                                                     *
+\subsection[Maybe2,3 types]{The @Maybe2@ and @Maybe3@ types}
+%*                                                                     *
+%************************************************************************
+
+\begin{code}
+data Maybe2 a b   = Just2 a b   | Nothing2  deriving (Eq,Show)
+data Maybe3 a b c = Just3 a b c | Nothing3  deriving (Eq,Show)
+\end{code}
+
+
+%************************************************************************
+%*                                                                     *
 \subsection[Maybe type]{The @Maybe@ type}
 %*                                                                     *
 %************************************************************************
@@ -173,3 +185,4 @@ returnMaB v = Succeeded v
 failMaB :: err -> MaybeErr val err
 failMaB e = Failed e
 \end{code}
+