Separate NondecreasingIndentation out into its own extension

[ghc-hetmet.git] / compiler / parser / Parser.y.pp

diff --git a/compiler/parser/Parser.y.pp b/compiler/parser/Parser.y.pp
index fd5b02c..9859949 100644 (file)
--- a/compiler/parser/Parser.y.pp
+++ b/compiler/parser/Parser.y.pp
@@ -8,15 +8,8 @@
 -- ---------------------------------------------------------------------------
 
 {
-{-# OPTIONS -Wwarn -w -XNoMonomorphismRestriction #-}
--- The NoMonomorphismRestriction deals with a Happy infelicity
---    With OutsideIn's more conservativ monomorphism restriction
---    we aren't generalising
---        notHappyAtAll = error "urk"
---    which is terrible.  Switching off the restriction allows
---    the generalisation.  Better would be to make Happy generate
---    an appropriate signature.
-
+{-# LANGUAGE BangPatterns #-} -- required for versions of Happy before 1.18.6
+{-# OPTIONS -Wwarn -w #-}
 -- The above warning supression flag is a temporary kludge.
 -- While working on this module you are encouraged to remove it and fix
 -- any warnings in the module. See
@@ -1208,15 +1201,20 @@ docdecld :: { LDocDecl }
         | docsection                            { L1 (case (unLoc $1) of (n, doc) -> DocGroup n doc) }
 
 decl   :: { Located (OrdList (LHsDecl RdrName)) }
-       : sigdecl                       { $1 }
-       | '!' aexp rhs                  {% do { pat <- checkPattern $2;
-                                               return (LL $ unitOL $ LL $ ValD ( 
-                                                       PatBind (LL $ BangPat pat) (unLoc $3)
-                                                               placeHolderType placeHolderNames)) } }
-        | infixexp opt_sig rhs          {% do { r <- checkValDef $1 $2 $3;
-                                                let { l = comb2 $1 $> };
-                                                return $! (sL l (unitOL $! (sL l $ ValD r))) } }
-        | docdecl                       { LL $ unitOL $1 }
+       : sigdecl               { $1 }
+
+        | '!' aexp rhs          {% do { let { e = LL (SectionR (LL (HsVar bang_RDR)) $2) };
+                                        pat <- checkPattern e;
+                                        return $ LL $ unitOL $ LL $ ValD $
+                                               PatBind pat (unLoc $3)
+                                                       placeHolderType placeHolderNames } }
+                                -- Turn it all into an expression so that
+                                -- checkPattern can check that bangs are enabled
+
+        | infixexp opt_sig rhs  {% do { r <- checkValDef $1 $2 $3;
+                                        let { l = comb2 $1 $> };
+                                        return $! (sL l (unitOL $! (sL l $ ValD r))) } }
+        | docdecl               { LL $ unitOL $1 }
 
 rhs    :: { Located (GRHSs RdrName) }
        : '=' exp wherebinds    { sL (comb3 $1 $2 $3) $ GRHSs (unguardedRHS $2) (unLoc $3) }
@@ -1358,8 +1356,8 @@ aexp2     :: { LHsExpr RdrName }
        | RATIONAL                      { sL (getLoc $1) (HsOverLit $! mkHsFractional (getRATIONAL $1) placeHolderType) }
 
         -- N.B.: sections get parsed by these next two productions.
-        -- This allows you to write, e.g., '(+ 3, 4 -)', which isn't correct Haskell98
-        -- (you'd have to write '((+ 3), (4 -))')
+        -- This allows you to write, e.g., '(+ 3, 4 -)', which isn't
+        -- correct Haskell (you'd have to write '((+ 3), (4 -))')
         -- but the less cluttered version fell out of having texps.
        | '(' texp ')'                  { LL (HsPar $2) }
        | '(' tup_exprs ')'             { LL (ExplicitTuple $2 Boxed) }
@@ -1419,8 +1417,8 @@ texp :: { LHsExpr RdrName }
        -- Note [Parsing sections]
        -- ~~~~~~~~~~~~~~~~~~~~~~~
        -- We include left and right sections here, which isn't
-       -- technically right according to Haskell 98.  For example
-       --      (3 +, True) isn't legal
+       -- technically right according to the Haskell standard.
+        -- For example (3 +, True) isn't legal.
        -- However, we want to parse bang patterns like
        --      (!x, !y)
        -- and it's convenient to do so here as a section