spans span (l,c) = GHC.srcSpanStart span <= loc && loc <= GHC.srcSpanEnd span
where loc = GHC.mkSrcLoc (GHC.srcSpanFile span) l c
+-- for now, use ANSI bold on Unixy systems. On Windows, we add a line
+-- of carets under the active expression instead. The Windows console
+-- doesn't support ANSI escape sequences, and most Unix terminals
+-- (including xterm) do, so this is a reasonable guess until we have a
+-- proper termcap/terminfo library.
+#if !defined(mingw32_TARGET_OS)
+do_bold = True
+#else
+do_bold = False
+#endif
+
start_bold = BS.pack "\ESC[1m"
end_bold = BS.pack "\ESC[0m"
| otherwise = 1
pad_after = 1
- highlight no line
+ highlight | do_bold = highlight_bold
+ | otherwise = highlight_carets
+
+ highlight_bold no line
| no == line1 && no == line2
= let (a,r) = BS.splitAt col1 line
(b,c) = BS.splitAt (col2-col1) r
BS.concat [a, end_bold, b]
| otherwise = line
+ highlight_carets no line
+ | no == line1 && no == line2
+ = BS.concat [line, nl, indent, BS.replicate col1 ' ',
+ BS.replicate (col2-col1) '^']
+ | no == line1
+ = BS.concat [line, nl, indent, BS.replicate col1 ' ',
+ BS.replicate (BS.length line-col1) '^']
+ | no == line2
+ = BS.concat [line, nl, indent, BS.replicate col2 '^']
+ | otherwise = line
+ where
+ indent = BS.pack " "
+ nl = BS.singleton '\n'
+
-- --------------------------------------------------------------------------
-- Tick arrays