From af9271a48ea51bd6beb41ac0c293c6e27d352391 Mon Sep 17 00:00:00 2001
From: Adam Sampson <ats@offog.org>
Date: Mon, 30 Oct 2006 23:30:25 +0000
Subject: [PATCH] Some nicer death code

---
 fco/ASTPasses.hs | 11 +++++------
 fco/Metadata.hs  |  8 ++++++++
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/fco/ASTPasses.hs b/fco/ASTPasses.hs
index b03c3fa..9d2cc33 100644
--- a/fco/ASTPasses.hs
+++ b/fco/ASTPasses.hs
@@ -1,12 +1,12 @@
--- Parses across the AST
+-- Passes across the AST
 
---module ASTPasses (astPasses) where
-module ASTPasses where
+module ASTPasses (astPasses) where
 
-import qualified AST as A
 import List
 import Data.Generics
 import Control.Monad.State
+import Metadata
+import qualified AST as A
 
 {- FIXME: Passes to add:
 calculate types
@@ -114,8 +114,7 @@ uniqueNamesPass p = evalState (doAny p) (0, [])
       (_, vars) <- get
       let s' = case lookup s vars of
                  Just n -> n
-                 Nothing -> "(not-declared-" ++ s ++ ")"
-                 --Nothing -> error $ "Name " ++ s ++ " not declared before use"
+                 Nothing -> dieP m $ "Name " ++ s ++ " not declared before use"
       return $ A.Name m s'
 
 cStyleNamesPass :: A.Process -> A.Process
diff --git a/fco/Metadata.hs b/fco/Metadata.hs
index 7ddce8d..fde8249 100644
--- a/fco/Metadata.hs
+++ b/fco/Metadata.hs
@@ -20,3 +20,11 @@ formatSourcePos m = case findSourcePos m of
                       Just (SourcePos f l c) -> "<@" ++ show l ++ ":" ++ show c ++ ">"
                       Nothing -> "<?>"
 
+die :: Monad m => String -> m a
+die s = error $ "error: " ++ s
+
+dieP :: Monad m => Meta -> String -> m a
+dieP m s = case findSourcePos m of
+             Just (SourcePos f l c) -> die $ f ++ ":" ++ (show l) ++ ":" ++ (show c) ++ ": " ++ s
+             Nothing -> die $ "unknown position: " ++ s
+