diff options
Diffstat (limited to 'compiler/utils/IOEnv.hs')
| -rw-r--r-- | compiler/utils/IOEnv.hs | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/compiler/utils/IOEnv.hs b/compiler/utils/IOEnv.hs index 728e55ca8d..fc513a0ad6 100644 --- a/compiler/utils/IOEnv.hs +++ b/compiler/utils/IOEnv.hs @@ -99,7 +99,9 @@ fixM f = IOEnv (\ env -> fixIO (\ r -> unIOEnv (f r) env)) --------------------------- tryM :: IOEnv env r -> IOEnv env (Either Exception r) --- Reflect UserError exceptions into IOEnv monad +-- Reflect UserError exceptions (only) into IOEnv monad +-- Other exceptions are not caught; they are simply propagated as exns +-- -- The idea is that errors in the program being compiled will give rise -- to UserErrors. But, say, pattern-match failures in GHC itself should -- not be caught here, else they'll be reported as errors in the program |