add homework files for lecture 2

1 files changed, 38 insertions, 0 deletions

diff --git a/lec02/Log.hs b/lec02/Log.hs
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+-- CIS 194 Homework 2
+
+module Log where
+
+import Control.Applicative
+
+data MessageType = Info
+                 | Warning
+                 | Error Int
+  deriving (Show, Eq)
+
+type TimeStamp = Int
+
+data LogMessage = LogMessage MessageType TimeStamp String
+                | Unknown String
+  deriving (Show, Eq)
+
+data MessageTree = Leaf
+                 | Node MessageTree LogMessage MessageTree
+  deriving (Show, Eq)
+
+-- | @testParse p n f@ tests the log file parser @p@ by running it
+--   on the first @n@ lines of file @f@.
+testParse :: (String -> [LogMessage])
+          -> Int
+          -> FilePath
+          -> IO [LogMessage]
+testParse parse n file = take n . parse <$> readFile file
+
+-- | @testWhatWentWrong p w f@ tests the log file parser @p@ and
+--   warning message extractor @w@ by running them on the log file
+--   @f@.
+testWhatWentWrong :: (String -> [LogMessage])
+                  -> ([LogMessage] -> [String])
+                  -> FilePath
+                  -> IO [String]
+testWhatWentWrong parse whatWentWrong file
+  = whatWentWrong . parse <$> readFile file