/dev/stdin

Bump version

dplyr 0.7.6

* `exprs()` is no longer exported to avoid conflicts with `Biobase::exprs()`
  (tidyverse#3638).

* The MASS package is explicitly suggested to fix CRAN warnings on R-devel
  (tidyverse#3657).

* Set operations like `intersect()` and `setdiff()` reconstruct groups metadata (tidyverse#3587).

* Using namespaced calls to `base::sort()` and `base::unique()` from C++ code
  to avoid ambiguities when these functions are overridden (tidyverse#3644).

* Fix rchk errors (tidyverse#3693).

dplyr 0.7.5

## Breaking changes for package developers

* The major change in this version is that dplyr now depends on the selecting
  backend of the tidyselect package. If you have been linking to
  `dplyr::select_helpers` documentation topic, you should update the link to
  point to `tidyselect::select_helpers`.

* Another change that causes warnings in packages is that dplyr now exports the
  `exprs()` function. This causes a collision with `Biobase::exprs()`. Either
  import functions from dplyr selectively rather than in bulk, or do not import
  `Biobase::exprs()` and refer to it with a namespace qualifier.

## Bug fixes

* Reindexing grouped data frames never updates the `"class"` attribute. This also avoids unintended updates to the original object (tidyverse#3438).

* `do()` operations with more than one named argument can access `.` (tidyverse#2998).

* Summaries of summaries (such as `summarise(b = sum(a), c = sum(b))`) are now
  computed using standard evaluation for simplicity and correctness, but
  slightly slower (tidyverse#3233).

* Fixed rare column name clash in joins with non-join columns of the same name in both tables (tidyverse#3266).

* Fix `summarise()` for empty data frames with zero columns (tidyverse#3071).

*  Fix `row_number()` and `ntile()` ordering to use the locale-dependent ordering functions in R when dealing with character vectors, rather than always using the C-locale ordering function in C (tidyverse#2792, @foo-bar-baz-qux).

* `distinct(data, "string")` now returns a one-row data frame again. (The previous behavior was to return the data unchanged.)

## Changes

* `sym()`, `syms()`, `expr()`, `exprs()` and `enexpr()` are now
  exported. `sym()` and `syms()` construct symbols from strings or character
  vectors. The `expr()` variants are equivalent to `quo()`, `quos()` and
  `enquo()` but return simple expressions rather than quosures. They support
  quasiquotation.

* dplyr now depends on the new tidyselect package to power `select()`,
  `rename()`, `pull()` and their variants (tidyverse#2896). Consequently
  `select_vars()`, `select_var()` and `rename_vars()` are
  soft-deprecated and will start issuing warnings in a future version.

  Following the switch to tidyselect, `select()` and `rename()` fully support
  character vectors. You can now unquote variables like this:

  ```
  vars <- c("disp", "cyl")
  select(mtcars, !! vars)
  select(mtcars, -(!! vars))
  ```

  Note that this only works in selecting functions because in other contexts
  strings and character vectors are ambiguous. For instance strings are a valid
  input in mutating operations and `mutate(df, "foo")` creates a new column by
  recycling "foo" to the number of rows.

* Support for raw vector columns in `mutate`, `summarise`, `arrange`, `group_by`
  and joins (minimal `raw` x `raw` support initially) (tidyverse#1803). 

* Hybrid evaluation simplifies `dplyr::foo` to `foo` (tidyverse#3309). Hybrid functions can now be masked by regular R functions to turn off hybrid evaluation (tidyverse#3255). The hybrid evaluator finds functions from dplyr even if dplyr is not attached (tidyverse#3456).

* Scoped select and rename functions (`select_all()`, `rename_if()` etc.) now work with grouped data frames, adapting the grouping as necessary (tidyverse#2947, tidyverse#3410). `group_by_at` can group by an existing grouping variable (tidyverse#3351). `arrange_at` can use grouping variables (tidyverse#3332). 

* `row_number()` works on empty subsets (tidyverse#3454).

* `bind_cols()` handles unnamed list (tidyverse#3402).

* `select()` and `vars()` now treat `NULL` as empty inputs (tidyverse#3023).

* Support `!!!` in `recode_factor()` (tidyverse#3390).

*  `distinct()` now supports renaming columns (tidyverse#3234).

* It is now illegal to use `data.frame` in the rhs of `mutate()` (tidyverse#3298). 

* `combine()` returns `logical()` when all inputs are `NULL` (or when there are no inputs) (tidyverse#3365, @zeehio).

* `bind_rows()` works around corrupt columns that have the object bit set while having no class attribute (tidyverse#3349). 

* `slice()` no longer enforce tibble classes when input is a simple `data.frame`, and ignores 0 (tidyverse#3297, tidyverse#3313).

* `transmute()` no longer prints a message when including a group variable.

## Documentation

* Improved documentation for set operations (tidyverse#3238, @edublancas).

* Improved documentation for `funs()` (tidyverse#3094).

## Error messages

* Dedicated error message when trying to use columns of the `Interval` or `Period` classes (tidyverse#2568).

* Show clear error message for bad arguments to `funs()` (tidyverse#3368).

* Add warning with explanation to `distinct()` if any of the selected columns are of type `list` (tidyverse#3088, @foo-bar-baz-qux).

* Better error message if dbplyr is not installed when accessing database backends (tidyverse#3225).

* Corrected error message when calling `cbind()` with an object of wrong length (tidyverse#3085).

* Better error message when joining data frames with duplicate or `NA` column names. Joining such data frames with a semi- or anti-join now gives a warning, which may be converted to an error in future versions (tidyverse#3243, tidyverse#3417).

* `distinct()` now gives a warning when used on unknown columns (tidyverse#2867, @foo-bar-baz-qux).

* `arrange()` fails gracefully on `data.frame` columns (tidyverse#3153).

* Added an `.onDetach()` hook that allows for plyr to be loaded and attached without the warning message that says functions in dplyr will be masked, since dplyr is no longer attached (tidyverse#3359, @jwnorman).

## Performance

* `sample_n()` and `sample_frac()` on grouped data frame are now faster especially for those with large number of groups (tidyverse#3193, @saurfang).

## Internal

* Compute variable names for joins in R (tidyverse#3430).

* Bumped Rcpp dependency to 0.12.15 to avoid imperfect detection of `NA` values in hybrid evaluation fixed in RcppCore/Rcpp#790 (tidyverse#2919).

* Avoid cleaning the data mask, a temporary environment used to evaluate expressions. If the environment, in which e.g. a `mutate()` expression is evaluated, is preserved until after the operation, accessing variables from that environment now gives a warning but still returns `NULL` (tidyverse#3318).

dplyr 0.7.4.9005

## Breaking changes for package developers

* The major change in this version is that dplyr now depends on the selecting
  backend of the tidyselect package. If you have been linking to
  `dplyr::select_helpers` documentation topic, you should update the link to
  point to `tidyselect::select_helpers`.

* Another change that causes warnings in packages is that dplyr now exports the
  `exprs()` function. This causes a collision with `Biobase::exprs()`. Either
  import functions from dplyr selectively rather than in bulk, or do not import
  `Biobase::exprs()` and refer to it with a namespace qualifier.

## Bug fixes

* Reindexing grouped data frames never updates the `"class"` attribute. This also avoids unintended updates to the original object (tidyverse#3438).

* `do()` operations with more than one named argument can access `.` (tidyverse#2998).

* Summaries of summaries (such as `summarise(b = sum(a), c = sum(b))`) are now
  computed using standard evaluation for simplicity and correctness, but
  slightly slower (tidyverse#3233).

* Fixed rare column name clash in joins with non-join columns of the same name in both tables (tidyverse#3266).

* Fix `summarise()` for empty data frames with zero columns (tidyverse#3071).

*  Fix `row_number()` and `ntile()` ordering to use the locale-dependent ordering functions in R when dealing with character vectors, rather than always using the C-locale ordering function in C (tidyverse#2792, @foo-bar-baz-qux).

## Changes

* `sym()`, `syms()`, `expr()`, `exprs()` and `enexpr()` are now
  exported. `sym()` and `syms()` construct symbols from strings or character
  vectors. The `expr()` variants are equivalent to `quo()`, `quos()` and
  `enquo()` but return simple expressions rather than quosures. They support
  quasiquotation.

* dplyr now depends on the new tidyselect package to power `select()`,
  `rename()`, `pull()` and their variants (tidyverse#2896). Consequently
  `select_vars()`, `select_var()` and `rename_vars()` are
  soft-deprecated and will start issuing warnings in a future version.

  Following the switch to tidyselect, `select()` and `rename()` fully support
  character vectors. You can now unquote variables like this:

  ```
  vars <- c("disp", "cyl")
  select(mtcars, !! vars)
  select(mtcars, -(!! vars))
  ```

  Note that this only works in selecting functions because in other contexts
  strings and character vectors are ambiguous. For instance strings are a valid
  input in mutating operations and `mutate(df, "foo")` creates a new column by
  recycling "foo" to the number of rows.

* Support for raw vector columns in `mutate`, `summarise`, `arrange`, `group_by`
  and joins (minimal `raw` x `raw` support initially) (tidyverse#1803). 

* Hybrid evaluation simplifies `dplyr::foo` to `foo` (tidyverse#3309). Hybrid functions can now be masked by regular R functions to turn off hybrid evaluation (tidyverse#3255). The hybrid evaluator finds functions from dplyr even if dplyr is not attached (tidyverse#3456).

* Scoped select and rename functions (`select_all()`, `rename_if()` etc.) now work with grouped data frames, adapting the grouping as necessary (tidyverse#2947, tidyverse#3410). `group_by_at` can group by an existing grouping variable (tidyverse#3351). `arrange_at` can use grouping variables (tidyverse#3332). 

* `row_number()` works on empty subsets (tidyverse#3454).

* `bind_cols()` handles unnamed list (tidyverse#3402).

* `select()` and `vars()` now treat `NULL` as empty inputs (tidyverse#3023).

* Support `!!!` in `recode_factor()` (tidyverse#3390).

*  `distinct()` now supports renaming columns (tidyverse#3234).

* It is now illegal to use `data.frame` in the rhs of `mutate()` (tidyverse#3298). 

* `combine()` returns `logical()` when all inputs are `NULL` (or when there are no inputs) (tidyverse#3365, @zeehio).

* `bind_rows()` works around corrupt columns that have the object bit set while having no class attribute (tidyverse#3349). 

* `slice()` no longer enforce tibble classes when input is a simple `data.frame`, and ignores 0 (tidyverse#3297, tidyverse#3313).

## Documentation

* Improved documentation for set operations (tidyverse#3238, @edublancas).

* Improved documentation for `funs()` (tidyverse#3094).

## Error messages

* Dedicated error message when trying to use columns of the `Interval` or `Period` classes (tidyverse#2568).

* Show clear error message for bad arguments to `funs()` (tidyverse#3368).

* Add warning with explanation to `distinct()` if any of the selected columns are of type `list` (tidyverse#3088, @foo-bar-baz-qux).

* Better error message if dbplyr is not installed when accessing database backends (tidyverse#3225).

* Corrected error message when calling `cbind()` with an object of wrong length (tidyverse#3085).

* Better error message when joining data frames with duplicate or `NA` column names. Joining such data frames with a semi- or anti-join now gives a warning, which may be converted to an error in future versions (tidyverse#3243, tidyverse#3417).

* `distinct()` now gives a warning when used on unknown columns (tidyverse#2867, @foo-bar-baz-qux).

* `arrange()` fails gracefully on `data.frame` columns (tidyverse#3153).

* Added an `.onDetach()` hook that allows for plyr to be loaded and attached without the warning message that says functions in dplyr will be masked, since dplyr is no longer attached (tidyverse#3359, @jwnorman).

## Performance

* `sample_n()` and `sample_frac()` on grouped data frame are now faster especially for those with large number of groups (tidyverse#3193, @saurfang).

## Internal

* Compute variable names for joins in R (tidyverse#3430).

* Bumped Rcpp dependency to 0.12.15 to avoid imperfect detection of `NA` values in hybrid evaluation fixed in RcppCore/Rcpp#790 (tidyverse#2919).

* Avoid cleaning the data mask, a temporary environment used to evaluate expressions. If the environment, in which e.g. a `mutate()` expression is evaluated, is preserved until after the operation, accessing variables from that environment now gives a warning but still returns `NULL` (tidyverse#3318).

dplyr 0.7.4.9004

* The hybrid evaluator finds functions from dplyr even if dplyr is not attached (tidyverse#3456).

* Dedicated error message when trying to use columns of the `Interval` or `Period` classes (tidyverse#2568).

* Improved documentation for set operations (tidyverse#3238, @edublancas).

dplyr 0.7.4.9003

* `row_number()` works on empty subsets (tidyverse#3454).

* Support `!!!` in `recode_factor()` (tidyverse#3390).

* Specify `[`-type base subsetting in filter docs.

* Hybrid functions can now be masked by regular R functions to turn off hybrid evaluation (tidyverse#3255).

* Reindexing grouped data frames never updates the `"class"` attribute. This also avoids unintended updates to the original object (tidyverse#3438).

* Avoid cleaning the data mask, a temporary environment used to evaluate expressions. If the environment, in which e.g. a `mutate()` expression is evaluated, is preserved until after the operation, accessing variables from that environment now gives a warning but still returns `NULL` (tidyverse#3318).

* `do()` operations with more than one named argument can access `.` (tidyverse#2998).

* Improve column name compatibility for `mutate_each()` and `summarize_each()` with dplyr 0.5.0 and earlier in an edge case (tidyverse#3020).

* Show clear error message for bad arguments to `funs()` (tidyverse#3368

).

* Improved documentation for `funs()` (tidyverse#3094).

* Compute variable names for joins in R (tidyverse#3430).

* Hybrid evaluation simplifies `dplyr::foo` to `foo` (tidyverse#3309)

* `bind_cols()` handles unnamed list (tidyverse#3402).

* `slice()` no longer enforce tibble classes when input is a simple `…

…data.frame`, and ignores 0 (tidyverse#3297, tidyverse#3313).

build on three flavors of R