From b2c785edfaacb9fc4f04dddec0930950c634855b Mon Sep 17 00:00:00 2001
From: krasimir <krasimir@chalmers.se>
Date: Thu, 18 Mar 2010 19:52:45 +0000
Subject: [PATCH] fix the precedence for patterns ~, - and @

---
 src/compiler/GF/Grammar/Parser.y   | 16 ++++++++++------
 src/compiler/GF/Grammar/Printer.hs | 12 ++++++------
 2 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/src/compiler/GF/Grammar/Parser.y b/src/compiler/GF/Grammar/Parser.y
index f1b429339..2346953a9 100644
--- a/src/compiler/GF/Grammar/Parser.y
+++ b/src/compiler/GF/Grammar/Parser.y
@@ -426,7 +426,7 @@ Exp4
   | 'pre' '{' String ';' ListAltern '}' { Alts (K $3, $5) }
   | 'pre' '{' Ident ';' ListAltern '}' { Alts (Vr $3, $5) }
   | 'strs' '{' ListExp '}'           { Strs $3       }
-  | '#' Patt2                        { EPatt $2      }
+  | '#' Patt3                        { EPatt $2      }
   | 'pattern' Exp5                   { EPattType $2  }
   | 'lincat' Ident Exp5              { ELincat $2 $3 }
   | 'lin' Ident Exp5                 { ELin $2 $3 }
@@ -477,18 +477,22 @@ Patt1 :: { Patt }
 Patt1
   : Ident ListPatt            { PC $1 $2 } 
   | Ident '.' Ident ListPatt  { PP $1 $3 $4 }
-  | Patt2 '*'                 { PRep $1 }
-  | Ident '@' Patt2           { PAs $1 $3 }
-  | '-' Patt2                 { PNeg $2 }
+  | Patt3 '*'                 { PRep $1 }
   | Patt2                     { $1 }
 
 Patt2 :: { Patt }
 Patt2
+  : Ident '@' Patt3           { PAs $1 $3 }
+  | '-' Patt3                 { PNeg $2 }
+  | '~' Exp6                  { PTilde $2 }
+  | Patt3                     { $1 } 
+
+Patt3 :: { Patt }
+Patt3
   : '?'                       { PChar } 
   | '[' String ']'            { PChars $2 }
   | '#' Ident                 { PMacro $2 }
   | '#' Ident '.' Ident       { PM $2 $4 }
-  | '~' Exp6                  { PTilde $2 }
   | '_'                       { PW }
   | Ident                     { PV $1 }
   | Ident '.' Ident           { PP $1 $3 [] }
@@ -529,7 +533,7 @@ ListPatt
 
 PattArg :: { Patt }
   : Patt2         { $1                }
-  | '{' Patt2 '}' { PImplArg $2       }
+  | '{' Patt '}'  { PImplArg $2       }
 
 Arg :: { [(BindType,Ident)] }
 Arg 
diff --git a/src/compiler/GF/Grammar/Printer.hs b/src/compiler/GF/Grammar/Printer.hs
index 12f574b52..15afef865 100644
--- a/src/compiler/GF/Grammar/Printer.hs
+++ b/src/compiler/GF/Grammar/Printer.hs
@@ -190,13 +190,13 @@ ppPatt q d (PAlt p1 p2) = prec d 0 (ppPatt q 0 p1 <+> char '|' <+> ppPatt q 1 p2
 ppPatt q d (PSeq p1 p2) = prec d 0 (ppPatt q 0 p1 <+> char '+' <+> ppPatt q 1 p2)
 ppPatt q d (PC f ps)    = if null ps
                             then ppIdent f
-                            else prec d 1 (ppIdent f <+> hsep (map (ppPatt q 2) ps))
+                            else prec d 1 (ppIdent f <+> hsep (map (ppPatt q 3) ps))
 ppPatt q d (PP f g ps)  = if null ps
                             then ppQIdent q f g
-                            else prec d 1 (ppQIdent q f g <+> hsep (map (ppPatt q 2) ps))
-ppPatt q d (PRep p)     = prec d 1 (ppPatt q 2 p <> char '*')
-ppPatt q d (PAs f p)    = prec d 1 (ppIdent f <> char '@' <> ppPatt q 2 p)
-ppPatt q d (PNeg p)     = prec d 1 (char '-' <> ppPatt q 2 p)
+                            else prec d 1 (ppQIdent q f g <+> hsep (map (ppPatt q 3) ps))
+ppPatt q d (PRep p)     = prec d 1 (ppPatt q 3 p <> char '*')
+ppPatt q d (PAs f p)    = prec d 2 (ppIdent f <> char '@' <> ppPatt q 3 p)
+ppPatt q d (PNeg p)     = prec d 2 (char '-' <> ppPatt q 3 p)
 ppPatt q d (PChar)      = char '?'
 ppPatt q d (PChars s)   = brackets (str s)
 ppPatt q d (PMacro id)  = char '#' <> ppIdent id
@@ -208,7 +208,7 @@ ppPatt q d (PFloat f)   = double f
 ppPatt q d (PString s)  = str s
 ppPatt q d (PR xs)      = braces (hsep (punctuate semi [ppLabel l <+> equals <+> ppPatt q 0 e | (l,e) <- xs]))
 ppPatt q d (PImplArg p) = braces (ppPatt q 0 p)
-ppPatt q d (PTilde t)   = char '~' <> ppTerm q 6 t
+ppPatt q d (PTilde t)   = prec d 2 (char '~' <> ppTerm q 6 t)
 
 ppValue :: TermPrintQual -> Int -> Val -> Doc
 ppValue q d (VGen i x)    = ppIdent x <> text "{-" <> int i <> text "-}" ---- latter part for debugging