From: simonm <unknown>
Date: Mon, 2 Feb 1998 16:47:53 +0000 (+0000)
Subject: [project @ 1998-02-02 16:47:53 by simonm]
X-Git-Tag: Approx_2487_patches~1017
X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=commitdiff_plain;h=98a1ebecb6d22d793b1d9f8e1d24ecbb5a2d130f

[project @ 1998-02-02 16:47:53 by simonm]
Short-cut unary '-' applied to an integer constant, before literal
overloading kicks in.
---

diff --git a/ghc/compiler/typecheck/TcExpr.lhs b/ghc/compiler/typecheck/TcExpr.lhs
index 34bb8cc..38a124e 100644
--- a/ghc/compiler/typecheck/TcExpr.lhs
+++ b/ghc/compiler/typecheck/TcExpr.lhs
@@ -185,7 +185,15 @@ tcExpr (HsLit lit@(HsString str)) res_ty
 tcExpr (HsPar expr) res_ty -- preserve parens so printing needn't guess where they go
   = tcExpr expr res_ty
 
-tcExpr (NegApp expr neg) res_ty = tcExpr (HsApp neg expr) res_ty
+-- perform the negate *before* overloading the integer, since the case
+-- of minBound on Ints fails otherwise.  Could be done elsewhere, but
+-- convenient to do it here.
+
+tcExpr (NegApp (HsLit (HsInt i)) neg) res_ty
+  = tcExpr (HsLit (HsInt (-i))) res_ty
+
+tcExpr (NegApp expr neg) res_ty 
+  = tcExpr (HsApp neg expr) res_ty
 
 tcExpr (HsLam match) res_ty
   = tcMatchExpected [] res_ty match	`thenTc` \ (match',lie) ->