1 files changed, 86 insertions, 0 deletions
diff --git a/testsuite/tests/simplCore/should_run/T3972A.hs b/testsuite/tests/simplCore/should_run/T3972A.hs
new file mode 100644
index 0000000000..b8202f7448
--- /dev/null
+++ b/testsuite/tests/simplCore/should_run/T3972A.hs
@@ -0,0 +1,86 @@
+
+module T3972A (Expr(..), Token(..), spanning, getSpan) where
+
+class Span a where
+   getSpan :: a -> SrcSpan
+
+spanning :: (Span a, Span b) => a -> b -> SrcSpan
+spanning x y = combineSrcSpans (getSpan x) (getSpan y)
+
+instance Span a => Span [a] where
+   getSpan [] = error "[]"
+   getSpan [x] = getSpan x
+   getSpan list@(x:_) = combineSrcSpans (getSpan x) (getSpan (last list))
+
+data SrcSpan
+
+  = SpanMultiLine
+    { span_start_row    :: !Int
+    , span_start_column :: !Int
+    , span_end_row      :: !Int
+    , span_end_column   :: !Int
+    }
+
+combineSrcSpans :: SrcSpan -> SrcSpan -> SrcSpan
+combineSrcSpans start end
+ = case row1 `compare` row2 of
+     LT -> SpanMultiLine row1 col1 row2 col2
+     _  -> SpanMultiLine row2 col2 row1 col1
+  where
+  row1 = startRow start
+  col1 = startCol start
+  row2 = endRow end
+  col2 = endCol end
+
+
+startRow :: SrcSpan -> Int
+startRow (SpanMultiLine { span_start_row = row }) = row
+
+endRow :: SrcSpan -> Int
+endRow (SpanMultiLine { span_end_row = row }) = row
+
+startCol :: SrcSpan -> Int
+startCol (SpanMultiLine { span_start_column = col }) = col
+
+endCol :: SrcSpan -> Int
+endCol (SpanMultiLine { span_end_column = col }) = col
+
+data Token
+   = T10 { token_SrcSpan :: SrcSpan }
+   | T11 { token_SrcSpan :: SrcSpan }
+   | T12 { token_SrcSpan :: SrcSpan }
+   | T13 { token_SrcSpan :: SrcSpan }
+   | T14 { token_SrcSpan :: SrcSpan }
+   | T15 { token_SrcSpan :: SrcSpan }
+   | T16 { token_SrcSpan :: SrcSpan }
+   | T17 { token_SrcSpan :: SrcSpan }
+   | T18 { token_SrcSpan :: SrcSpan }
+   | T19 { token_SrcSpan :: SrcSpan }
+   | T20 { token_SrcSpan :: SrcSpan }
+   | T21 { token_SrcSpan :: SrcSpan }
+   | T22 { token_SrcSpan :: SrcSpan }
+   | T23 { token_SrcSpan :: SrcSpan }
+   | T24 { token_SrcSpan :: SrcSpan }
+
+instance Span Token where
+  getSpan = token_SrcSpan
+
+data Expr
+   = E10 { expr_SrcSpan :: SrcSpan }
+   | E11 { expr_SrcSpan :: SrcSpan }
+   | E12 { expr_SrcSpan :: SrcSpan }
+   | E13 { expr_SrcSpan :: SrcSpan }
+   | E14 { expr_SrcSpan :: SrcSpan }
+   | E15 { expr_SrcSpan :: SrcSpan }
+   | E16 { expr_SrcSpan :: SrcSpan }
+   | E17 { expr_SrcSpan :: SrcSpan }
+   | E18 { expr_SrcSpan :: SrcSpan }
+   | E19 { expr_SrcSpan :: SrcSpan }
+   | E20 { expr_SrcSpan :: SrcSpan }
+   | E21 { expr_SrcSpan :: SrcSpan }
+   | E22 { expr_SrcSpan :: SrcSpan }
+   | E23 { expr_SrcSpan :: SrcSpan }
+   | E24 { expr_SrcSpan :: SrcSpan }
+
+instance Span Expr where
+   getSpan = expr_SrcSpan