(WIP) Changes to improve data.table completion #20
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- Adds `ncm_r_dt` setting. When set, this changes the regular expression that's used to check whether the cursor is inside the brackets of a data.frame (or data.table). This causes completions to be offered before a comma is typed, which means column names can be completed in the 'i' component of a data.table command, which occurs before the first comma i.e. DT[i, j, by] - Changes completion behaviour so that matches are refreshed as the user types more. This means that function names are now offered as completions after the the first comma has been typed within a data.table command. - Adds test cases for the new data.table completion behaviour
`data.table` objects are detected automatically using the omni object match list. Also: - Adds support for completion when using `data.table`s with `magrittr` pipes, using `.` to refer to the 'parent' DT (note that as a side-effect, ordinary `data.frame`s can be used in the same way and completion work as expected) - In order to get this pipe behaviour to work, the regular expression for checking if completion is happening inside the brackets of a `data.frame` was changed to allow dots in the name of the DF. This could be considered a bug fix since previously completion inside brackets did not work as expected if the DF had dots in its name.
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I've worked on this a bit more now, the behaviour is only triggered for DT %>%
.[i, j, by]Note that you can also do this with ordinary DF %>%
.[, "column_name"]and completion works as expected in this case too. Coincidentally, this pipe completion behaviour isn't supported by RStudio :) When adding this pipe behaviour I noticed that the regex used for detecting if completion is happening inside the brackets of a df doesn't allow for the name of the df to contain dots (since |
This is where I've got to so far with the data.table completion behaviour as discussed in #18. There are two significant changes:
The regular expression for checking if the completion is happening inside the brackets of a data.frame (or data.table) is changed, so that completions are offered before the first comma is typed. This behaviour can be switched on and off with the
ncm_r_dtsetting, which is also added. I think it would be best to change this so that the class of the object is automatically detected, and this behaviour only happens when the object is a data.table. I think this should be possible - will work on it next.The other objective was to get function names as completions after the first comma is typed in a data.table command. The only way I've found to do this is to set
refresh = 1in the call tocomplete(), so that completions are refreshed as the user types. This is somewhat unsatisfactory since it isn't toggled by thencm_r_dtsetting (though could be I think), and presumably goes against the reason why you originally chose not to enable refreshing. Maybe it negatively impacts performance? I've not noticed a slowdown yet, but have only been working with small files. Let me know if you can think of a better solution to this problem.I've also added some test cases to demonstrate the behaviour I'm trying to get (which should currently all pass).