-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 12/13/10 09:15 , Jacek Generowicz wrote: > untilQuit' = (fmap (takeWhile (/= "quit"))) (sequence $ map (>>= report) > (repeat getLine)) > > -- The latter version shows the report, but it doesn't stop at the > -- appropriate place, so I'm guessing that I'm being bitten by my > -- ignorance about the interaction of actions and lazyness.
The reason this doesn't stop where you expect it to is that sequence is effectively strict (that is, it will keep going until the list is exhausted), but repeat creates an infinite list. You want the stop condition between the map-report and the repeat-getLine. - -- brandon s. allbery [linux,solaris,freebsd,perl] allb...@kf8nh.com system administrator [openafs,heimdal,too many hats] allb...@ece.cmu.edu electrical and computer engineering, carnegie mellon university KF8NH -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.10 (Darwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk0OWJQACgkQIn7hlCsL25Wb2gCgw3GKF/rBdXL2LIsV5qUVSa1M ZfEAoL5Vzd9+F7+NDqOAP7s2pyxtmJ0S =bU/D -----END PGP SIGNATURE----- _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
