Make dataToQa aware of Data instances which use functions to implement toConstr

Trac #10796 exposes a way to make `template-haskell`'s `dataToQa` function
freak out if using a `Data` instance that produces a `Constr` (by means of
`toConstr`) using a function name instead of a data constructor name. While
such `Data` instances are somewhat questionable, they are nevertheless present
in popular libraries (e.g., `containers`), so we can at least make `dataToQa`
aware of their existence.

In order to properly distinguish strings which represent variables (as opposed
to data constructors), it was necessary to move functionality from `Lexeme` (in
`ghc`) to `GHC.Lexeme` in a new `ghc-boot` library (which was previously named
`bin-package-db`).

Reviewed By: goldfire, thomie

Differential Revision: https://phabricator.haskell.org/D1313

GHC Trac Issues: #10796

3 files changed, 8 insertions, 22 deletions

diff --git a/compiler/basicTypes/Lexeme.hs b/compiler/basicTypes/Lexeme.hs
index a2409614d1..2049e001bf 100644
--- a/compiler/basicTypes/Lexeme.hs
+++ b/compiler/basicTypes/Lexeme.hs
@@ -6,11 +6,11 @@
 
 module Lexeme (
           -- * Lexical characteristics of Haskell names
-  
+
           -- | Use these functions to figure what kind of name a 'FastString'
           -- represents; these functions do /not/ check that the identifier
           -- is valid.
-  
+
         isLexCon, isLexVar, isLexId, isLexSym,
         isLexConId, isLexConSym, isLexVarId, isLexVarSym,
         startsVarSym, startsVarId, startsConSym, startsConId,
@@ -33,6 +33,8 @@ import Util ((<||>))
 import Data.Char
 import qualified Data.Set as Set
 
+import GHC.Lexeme
+
 {-
 
 ************************************************************************
@@ -86,22 +88,6 @@ isLexVarSym fs                          -- Infix identifiers e.g. "+"
       (c:cs) -> startsVarSym c && all isVarSymChar cs
         -- See Note [Classification of generated names]
 
--------------
-startsVarSym, startsVarId, startsConSym, startsConId :: Char -> Bool
-startsVarSym c = startsVarSymASCII c || (ord c > 0x7f && isSymbol c)  -- Infix Ids
-startsConSym c = c == ':'               -- Infix data constructors
-startsVarId c  = c == '_' || case generalCategory c of  -- Ordinary Ids
-  LowercaseLetter -> True
-  OtherLetter     -> True   -- See #1103
-  _               -> False
-startsConId c  = isUpper c || c == '('  -- Ordinary type constructors and data constructors
-
-startsVarSymASCII :: Char -> Bool
-startsVarSymASCII c = c `elem` "!#$%&*+./<=>?@\\^|~-"
-
-isVarSymChar :: Char -> Bool
-isVarSymChar c = c == ':' || startsVarSym c
-
 {-
 
 ************************************************************************
@@ -113,7 +99,7 @@ isVarSymChar c = c == ':' || startsVarSym c
 -}
 
 ----------------------
--- External interface 
+-- External interface
 ----------------------
 
 -- | Is this an acceptable variable name?
@@ -237,7 +223,7 @@ okSymChar c
       ModifierSymbol       -> True
       OtherSymbol          -> True
       _                    -> False
-    
+
 -- | All reserved identifiers. Taken from section 2.4 of the 2010 Report.
 reservedIds :: Set.Set String
 reservedIds = Set.fromList [ "case", "class", "data", "default", "deriving"
diff --git a/compiler/ghc.cabal.in b/compiler/ghc.cabal.in
index 37a4f281d6..f068eb2458 100644
--- a/compiler/ghc.cabal.in
+++ b/compiler/ghc.cabal.in
@@ -55,7 +55,7 @@ Library
                    template-haskell,
                    hpc,
                    transformers,
-                   bin-package-db,
+                   ghc-boot,
                    hoopl
 
     if os(windows)
diff --git a/compiler/main/PackageConfig.hs b/compiler/main/PackageConfig.hs
index f3cdac77da..9e9775bc04 100644
--- a/compiler/main/PackageConfig.hs
+++ b/compiler/main/PackageConfig.hs
@@ -37,7 +37,7 @@ import Module
 import Unique
 
 -- -----------------------------------------------------------------------------
--- Our PackageConfig type is the InstalledPackageInfo from bin-package-db,
+-- Our PackageConfig type is the InstalledPackageInfo from ghc-boot,
 -- which is similar to a subset of the InstalledPackageInfo type from Cabal.
 
 type PackageConfig = InstalledPackageInfo