parley seems to insert the same sexpression to the reader again when getting input while sleeping

[ckeen]

See ​http://paste.call-cc.org/paste?id=1f10cc1f4285e1b1a4de027bc05a3ae30652121b

[LemonBoy]

There are a few problems here:

• In parley we get a non-false prev-input with the contents of the typeahead buffer in it so we have to process every element one by one before reading from the "real" prompt. Now, the (eof-object? (peek-char in) condition doesn't make any sense because you want to process in until an #!eof occurs and then switch to real-in-port as soon as the typeahead buffer has been completely processed. The #<unspecified> value you see in the trace comes from the other arm of the if.
• The use of object-copy is dangerous, especially when the state record contains references to port objects. With the adjustments outlined above I found that parley would crash the csi instance due to heap exhaustion while it was trying to copy such an object.
• (parley "") gives an error, this is not really a problem but it could give a better error.