0
initials :: String -> String -> String
initials firstname lastname = [f] ++ ". " ++ [l] ++ "."
    where (f:_) = firstname
          (l:_) = lastname

For this code. I got error 

parse error on input `='

Why?

Kirk Woll
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Anders Lind
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  • I didn't... http://codepad.org/LVecpglP The only error I think was the last line was not properly indented. After you corrected it... the parse error should go – A. K. May 06 '12 at 01:17

2 Answers2

4

You use a tab character before the where keyword. To GHC it looks like this:

␉       where␠(f:_)␠=␠firstname
␠␠␠␠␠␠␠␠␠(l:_)␠=␠lastname

So, GHC thinks that the first line in the where block starts at column 14 (tab counts for 8 columns iirc) while the second line starts at column 9, which causes the error.

You should use a good text editor that converts tabs into 4 spaces for you.

dflemstr
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4

By the way, you don't need the helper functions, you can directly pattern match on the arguments

initials :: String -> String -> String
initials (f:_) (l:_) = [f,'.',' ',l,'.']
Landei
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