add 'frame_data() (#804)

[kevinushey]

This PR implements the proposed

frame_data(
    ~colA, ~colB,
    "a", 1,
    "b", 2
)

as a means of constructing data_frame. tibble is also included as an alias, because it's too awesome a name not to use.

[hadley]

Nice! Could you please add a bullet to NEWS?

[kevinushey]

Just as you posted ;)

[hadley]

Thanks!

[krlmlr]

Constructing tables with more than two rows doesn't work for me (1405946):

tbl <- dplyr::tibble(
  ~a, ~b,
  "1", 1,
  "1", 2,
  "2", 1)

tbl

## Source: local data frame [2 x 2]
## 
##       a     b
##   (chr) (chr)
## 1     1     1
## 2     2     2

tbl <- dplyr::tibble(
  ~a, ~b,
  "1", 1,
  "1", 2,
  "2", 2,
  "2", 1)

tbl

## Source: local data frame [2 x 2]
## 
##       a     b
##   (chr) (dbl)
## 1     1     1
## 2     2     2

tbl <- dplyr::tibble(
  ~a, ~b, ~Freq,
  1, 1, 5,
  1, 2, 6,
  2, 2, 7,
  2, 1, 8)

tbl

## Source: local data frame [3 x 3]
## 
##       a     b  Freq
##   (dbl) (dbl) (dbl)
## 1     1     1     5
## 2     2     6     2
## 3     7     2     1

I have a failing test case in a branch.

[kevinushey]

Thanks @krlmlr -- I have a PR up that should fix this. #1377

Hopefully we can get this in before the dplyr submission...

[klmr]

This needs better documentation. I’ve just read the above examples and the code and I still had no idea what this function actually does. Only once I read the fix in #1377 did it click.

[lock]

This old issue has been automatically locked. If you believe you have found a related problem, please file a new issue (with reprex) and link to this issue. https://reprex.tidyverse.org/