Implement col_duration()

[sjackman]

I have a table of time durations in hms format. The number of hours can be greater than 24. Parsing this column with col_time fails with

Warning: 1 parsing failure.
row       col   expected      actual
  5 Wallclock valid date 24:56:18.90

My workaround is to use col_string and then parse the time format with hms(roll=TRUE). My suggestion for possible solutions would be to either add a col_duration parser, or add a roll=TRUE parameter to col_time.

[jimhester]

Reprex is

library(readr)
parse_time("24:56:18.90", format = "%H:%M:%S")
#> Warning: 1 parsing failure.
#> row col   expected      actual
#>   1  -- valid date 24:56:18.90
#> NA

[jimhester]

This is unfortunately tricky to implement with the current implementation

[hadley]

This needs a completely new collector for durations.

[krlmlr]

Same for negative times:

readr::parse_time("-12:34:56")
#> Warning: 1 parsing failure.
#> row col   expected    actual
#>   1  -- time like  -12:34:56
#> NA

^{Created on 2019-10-03 by the reprex package (v0.3.0)}

Can we solve it by a new placeholder %h that collects unrestricted signed hours, and check valid values when we collect %H? A new collector seems like too much work for too little gain.

[jimhester]

We have the new placeholder, so I think that should be sufficient to close this.