MIN Do not fail when merging empty files

closes #113
ngless-toolkit · May 23, 2022 · b0d75c9 · b0d75c9
1 parent 3dfa267
commit b0d75c9
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/NGLess/StandardModules/Parallel.hs b/NGLess/StandardModules/Parallel.hs
@@ -430,7 +430,9 @@ mergeCounts ss = do
         start <- forM ss $ \s -> do
             (s', v) <- lift $ s $$+ (CL.mapM (splitAtTab . unwrapByteLine) .| CC.head)
             case v of
-                Nothing -> throwShouldNotOccur "Trying to merge a headerless file"
+                Nothing -> do
+                    lift $ outputListLno' WarningOutput ["Merging empty file"]
+                    return (s', placeholder 1)
                 Just (_,hs) -> do
                     let p = placeholder (B8.count '\t' hs)
                     return (s', p)