Non-standard evaluation in data.table()

[maurolepore]

#Hi @ervanSTRI and all users of data.table,

If you write functions with the package data.table, you may need to learn a bit about non-standard evaluation; or you may get unexpected or silent errors. To learn generally about non-standard evaluation, I recommend this: http://adv-r.had.co.nz/Computing-on-the-language.html

data.table, at least the by argument, seems to use non-standard evaluation. Non-standard evaluation is great when you work interactively; but it can bite you if you use it inside the functions you write. In the base case scenario, the problem will be that you get an unexpected error. In the worse case scenario, the error will be silent: you will get output but it is wrong.

I am not yet familiar with data.table, and the best I can do right now is to point you to examples of
non-standard evaluation in the package dplyr.

dplyr also uses non-standard evaluation; and provides an approach to writing functions with dplyr that is called tidy eval: http://dplyr.tidyverse.org/articles/programming.html.

[djj4tree]

I use data.table frequently as it is optimized for large data sets. What was the original issue here? And what is meant my non-standard evaluation?