Pretty console output doesn't restore terminal cursor (Lighthouse #3)

[fatuhoku]

Originally reported by Edward Z. Yang | August 26th, 2010 @ 06:31 PM

Run a test-framework driver.

Expected: When it's done, my terminal cursor is restored
Actual: Terminal cursor not restored.

This might be ansi-terminal/ansi-wl-pprint's fault, or we might not be calling the correct reset frob.

[fatuhoku]

Edward Z. Yang replies on August 26th, 2010 @ 10:34 PM

Extra information: this only seems to occur when using runghc, not when running a compiled binary.

[fatuhoku]

Edward Z. Yang replies on August 26th, 2010 @ 10:45 PM

Fix is to explicitly flush after you restore the cursor:

hideCursorDuring :: IO a -> IO a
hideCursorDuring action = bracket hideCursor (const (showCursor >> hFlush stdout)) (const action)

[fatuhoku]

Edward Z. Yang replies on August 26th, 2010 @ 10:48 PM

See also here; it looks like this got fixed in GHC 6.12.3.