[[!comment format=mdwn
 username="https://www.google.com/accounts/o8/id?id=AItOawmqWbWVRH2k9spSMqKfIXBP1G3ekkj9Igg"
 nickname="Rado"
 subject="problem installing using cabal: language-javascript missing"
 date="2014-03-28T22:38:04Z"
 content="""
Configuring gnuidn-0.2.1...
cabal: The program c2hs is required but it could not be found.
Failed to install gnuidn-0.2.1
Configuring language-javascript-0.5.9...
cabal: The program happy version >=1.18.5 is required but it could not be
found.
Failed to install language-javascript-0.5.9
cabal: Error: some packages failed to install:
git-annex-5.20140320 depends on language-javascript-0.5.9 which failed to
install.
gnuidn-0.2.1 failed during the configure step. The exception was:
ExitFailure 1
hjsmin-0.1.4.6 depends on language-javascript-0.5.9 which failed to install.
language-javascript-0.5.9 failed during the configure step. The exception was:
ExitFailure 1
network-protocol-xmpp-0.4.6 depends on gnuidn-0.2.1 which failed to install.
yesod-static-1.2.2.4 depends on language-javascript-0.5.9 which failed to
install.
[r-c@rc-laptop ~]$ cabal install language-javascript
Resolving dependencies...
Configuring language-javascript-0.5.9...
cabal: The program happy version >=1.18.5 is required but it could not be
found.
Failed to install language-javascript-0.5.9
cabal: Error: some packages failed to install:
language-javascript-0.5.9 failed during the configure step. The exception was:
ExitFailure 1

Can you help how to solve?
"""]]