[project @ 2004-11-29 16:16:57 by simonpj]

Update ambiguity errors

diff --git a/ghc/compiler/parser/Parser.y.pp b/ghc/compiler/parser/Parser.y.pp
index e8144a6..8305022 100644 (file)
--- a/ghc/compiler/parser/Parser.y.pp
+++ b/ghc/compiler/parser/Parser.y.pp
@@ -46,36 +46,49 @@ import GLAEXTS
 
 {-
 -----------------------------------------------------------------------------
-Conflicts: 33 shift/reduce, [SDM 19/9/2002]
+Conflicts: 34 shift/reduce (1.15)
 
-10 for abiguity in 'if x then y else z + 1'            [State 136]
+10 for abiguity in 'if x then y else z + 1'            [State 178]
        (shift parses as 'if x then y else (z + 1)', as per longest-parse rule)
        10 because op might be: : - ! * . `x` VARSYM CONSYM QVARSYM QCONSYM
 
-1 for ambiguity in 'if x then y else z with ?x=3'      [State 136]
-       (shift parses as 'if x then y else (z with ?x=3)'
-
-1 for ambiguity in 'if x then y else z :: T'           [State 136]
+1 for ambiguity in 'if x then y else z :: T'           [State 178]
        (shift parses as 'if x then y else (z :: T)', as per longest-parse rule)
 
-4 for ambiguity in 'if x then y else z -< e'
+4 for ambiguity in 'if x then y else z -< e'           [State 178]
        (shift parses as 'if x then y else (z -< T)', as per longest-parse rule)
+       There are four such operators: -<, >-, -<<, >>-
+
+
+2 for ambiguity in 'case v of { x :: T -> T ... } '    [States 11, 253]
+       Which of these two is intended?
+         case v of
+           (x::T) -> T         -- Rhs is T
+    or
+         case v of
+           (x::T -> T) -> ..   -- Rhs is ...
 
-8 for ambiguity in 'e :: a `b` c'.  Does this mean     [States 160,246]
+8 for ambiguity in 'e :: a `b` c'.  Does this mean     [States 11, 253]
        (e::a) `b` c, or 
        (e :: (a `b` c))
+    As well as `b` we can have !, QCONSYM, and CONSYM, hence 3 cases
+    Same duplication between states 11 and 253 as the previous case
 
-1 for ambiguity in 'let ?x ...'                                [State 268]
+1 for ambiguity in 'let ?x ...'                                [State 329]
        the parser can't tell whether the ?x is the lhs of a normal binding or
        an implicit binding.  Fortunately resolving as shift gives it the only
        sensible meaning, namely the lhs of an implicit binding.
 
-1 for ambiguity in '{-# RULES "name" [ ... #-}         [State 332]
+1 for ambiguity in '{-# RULES "name" [ ... #-}         [State 382]
        we don't know whether the '[' starts the activation or not: it
        might be the start of the declaration with the activation being
        empty.  --SDM 1/4/2002
 
-1 for ambiguity in '{-# RULES "name" forall = ... #-}'         [State 394]
+6 for conflicts between `fdecl' and `fdeclDEPRECATED',         [States 393,394]
+       which are resolved correctly, and moreover, 
+       should go away when `fdeclDEPRECATED' is removed.
+
+1 for ambiguity in '{-# RULES "name" forall = ... #-}'         [State 474]
        since 'forall' is a valid variable name, we don't know whether
        to treat a forall on the input as the beginning of a quantifier
        or the beginning of the rule itself.  Resolving to shift means
@@ -83,10 +96,6 @@ Conflicts: 33 shift/reduce, [SDM 19/9/2002]
        This saves explicitly defining a grammar for the rule lhs that
        doesn't include 'forall'.
 
-6 for conflicts between `fdecl' and `fdeclDEPRECATED',         [States 384,385]
-       which are resolved correctly, and moreover, 
-       should go away when `fdeclDEPRECATED' is removed.
-
 -- ---------------------------------------------------------------------------
 -- Adding location info