Not quite code but... here is an example of parsing CSV http://book.realworldhaskell.org/read/using-parsec.html and here is a library that you can use which is similar http://hackage.haskell.org/package/csv These approaches give you a 2D String list that you can do whatever you want with. if you need to turn a string into a double and you know the string is well formed i think the syntax looks like
let doubleVal = read stringVal :: Double
There are better ways to do this if you need to be able to handle
formatting errors but I don't know them off the top of my head
-Keith
On Wed, Sep 2, 2009 at 6:40 PM, Hong Yang
I need to process csv files that have the characteristics as follows: 1) each file has thousands of columns which have String, Int, and Double types 2) the number of columns may change 3) for those columns whose name do not change, their location may change
I want to process some columns in 3) using Haskell.
In Perl, I can easily have the code like below:
use Text::CSV; my $csv = Text::CSV->new( { allow_whitespace => 1 } ); open my $temp, "<", "temp.csv" or die "Cannot open temp.csv! ($!)"; my @fields = @{ $csv->getline($temp) }; $csv->column_names(@fields); while ( my $hr = $csv->getline_hr($temp) ) { my $sn = $hr->{"UNIT:unitSerialNumber"}; # processing goes here ... } close $temp;
Can someone please give me an equivalent code in Haskell? Then I can digest and expand it.
Thanks,
Hong
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