Help the user when she tries to do :history without :trace
authorPepe Iborra <mnislaih@gmail.com>
Sat, 8 Dec 2007 18:09:18 +0000 (18:09 +0000)
committerPepe Iborra <mnislaih@gmail.com>
Sat, 8 Dec 2007 18:09:18 +0000 (18:09 +0000)
commitcf71c5a6df7c7fea777da0e0b91e937538287caa
tree127110006efef6ab25d9a6021b8714b993d5ece6
parent4d71f5ee6dbbfedb4a55767e4375f4c0aadf70bb
Help the user when she tries to do :history without :trace

Teach GHCi to show a "perhaps you forgot to use :trace?" when
it finds that the user is trying to retrieve an empty :history
compiler/ghci/InteractiveUI.hs