[Haskell-cafe] Parsing a matrix table with Data.Frames

William Yager will.yager at gmail.com
Wed Jun 6 00:34:11 UTC 2018

What's the issue you're running into? If it's confusion with the API,
hopefully this example is helpful:

> readRow (ParserOptions Nothing "," NoQuoting) "bill,true,true,false" ::
Rec (Either Text) ["Name" :-> Text, "Cat" :-> Bool, "Dog" :-> Bool,
"Goldfish" :-> Bool]

{Right Name :-> "bill", Right Cat :-> True, Right Dog :-> True, Right
Goldfish :-> False}

Requires OverloadedStrings, DataKinds, TypeOperators.

If you then want to extract data you can then do something like

> rget (Proxy :: Proxy ("Name" :-> Text)) row

Right Name :-> "bill"

I assume there is some easier API for this (looks like via template
haskell?). Seems kind of sad if there's no convenient way to do things
without using TH, but I don't see anything obvious.


On Tue, Jun 5, 2018 at 5:58 PM, Tyson Whitehead <twhitehead at gmail.com>

> I have a case where some of my data is stored in CSV matrix form like this
> example of a table telling whether person i has pet j
> ,cat,dog,goldfish
> bill,true,true,false
> sue,false,true,true
> fred,false,false,true
> I can't see any obvious way to read this sort of thing in with the
> Data.Frames package.  Would love to be told differently.
> Thanks!  -Tyson
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