X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2FhsSyn%2FHsLit.lhs;fp=compiler%2FhsSyn%2FHsLit.lhs;h=4a565ff8ba202a795bfed58423759f2a180da175;hp=0874dda85815c116abd60da8f908ffbc8bb92078;hb=ca53c38335cdc671f0b1e0949aa1514fc3fd72a5;hpb=4f8d714962667c219de4e684fe069136a0f78729

diff --git a/compiler/hsSyn/HsLit.lhs b/compiler/hsSyn/HsLit.lhs
index 0874dda..4a565ff 100644
--- a/compiler/hsSyn/HsLit.lhs
+++ b/compiler/hsSyn/HsLit.lhs
@@ -63,8 +63,7 @@ instance Eq HsLit where
 data HsOverLit id 	-- An overloaded literal
   = OverLit {
 	ol_val :: OverLitVal, 
-	ol_rebindable :: Bool,		-- True <=> rebindable syntax
-					-- False <=> standard syntax
+	ol_rebindable :: Bool,		-- Note [ol_rebindable]
 	ol_witness :: SyntaxExpr id,	-- Note [Overloaded literal witnesses]
 	ol_type :: PostTcType }
   deriving (Data, Typeable)
@@ -79,6 +78,19 @@ overLitType :: HsOverLit a -> Type
 overLitType = ol_type
 \end{code}
 
+Note [ol_rebindable]
+~~~~~~~~~~~~~~~~~~~~
+The ol_rebindable field is True if this literal is actually 
+using rebindable syntax.  Specifically:
+
+  False iff ol_witness is the standard one
+  True  iff ol_witness is non-standard
+
+Equivalently it's True if
+  a) RebindableSyntax is on
+  b) the witness for fromInteger/fromRational/fromString
+     that happens to be in scope isn't the standard one
+
 Note [Overloaded literal witnesses]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *Before* type checking, the SyntaxExpr in an HsOverLit is the
@@ -89,7 +101,7 @@ This witness should replace the literal.
 
 This dual role is unusual, because we're replacing 'fromInteger' with 
 a call to fromInteger.  Reason: it allows commoning up of the fromInteger
-calls, which wouldn't be possible if the desguarar made the application
+calls, which wouldn't be possible if the desguarar made the application.
 
 The PostTcType in each branch records the type the overload literal is
 found to have.