purrr no longer depends on lazyeval or Rcpp (or dplyr, as of the previous version). This makes the dependency graph of the tidyverse simpler, and makes purrr more suitable as a dependency of lower-level packages.
There have also been two changes to eliminate name conflicts between purrr and dplyr:
-
order_by()
,sort_by()
andsplit_by()
have been removed.order_by()
conflicted withdplyr::order_by()
and the complete family doesn't feel that useful. Use tibbles instead (#217). -
contains()
has been renamed tohas_element()
to avoid conflicts with dplyr (#217).
-
as_function()
is nowas_mapper()
because it is a tranformation that makes sense primarily for mapping functions, not in general (#298)..null
has been renamed to.default
to better reflect its intent (#298)..default
is returned whenever an element is absent or empty (#231, #254). -
Recursive indexing can now extract objects out of environments (#213) and S4 objects (#200), as well as lists.
-
get_attr()
makes it possible to extract from attributes likemap(list(iris, mtcars), get_attr("row.names"))
. -
The argument list for formula-functions has been tweaked so that you can refer to arguments by position with
..1
,..2
, and so on. This makes it possible to use the formula shorthand for functions with more than two arguments (#289). -
possibly()
,safely()
and friends no longer capture interrupts: this means that you can now terminate a mapper using one of these with Escape or Ctrl + C (#314)
-
All map functions now treat
NULL
the same way as an empty vector (#199), and return an empty vector if any input is an empty vector. -
All
map()
functions now force their arguments in the same way that base R does forlapply()
(#191). This makesmap()
etc easier to use when generating functions. -
A new family of "indexed" map functions,
imap()
,imap_lgl()
etc, provide a short-hand formap2(x, names(x))
ormap2(x, seq_along(x))
(#240). -
The data frame suffix
_df
has been (soft) deprecated in favour of_dfr
to more clearly indicate that it's a row-bind. All variants now also have a_dfc
for column binding (#167). (These will not be terribly useful untildplyr::bind_rows()
/dplyr::bind_cols()
have better semantics for vectors.)
map()
always returns a list, regardless of the input type. A new modify()
family returns the same output of the type as the input .x
. They rely on the semantics of [<-
so modify()
is shorthand for x[] <- map(x, f)
.
-
modify_if()
andmodify_at()
replace the now deprecatedmap_at()
andmap_if()
(#169, #292). If you want the previous behaviour, just coerce.x
to a list.at_depth()
has been renamed tomodify_depth()
. -
modify_depth()
gains new.ragged
argument, and negative depths are now computed relative to the deepest component of the list (#236). -
map_at()
andmap_if()
have been deprecated. Please usemodify_at()
andmodify_if()
instead .
-
auto_browse(f)
returns a new function that automatically callsbrowser()
iff
throws an error (#281). -
depth()
computes the depth (i.e. the number of levels of indexing) or a vector (#243). -
reduce2()
andreduce2_right()
make it possible to reduce with a 3 argument function where the first argument is the accumulated value, the second argument is.x
, and the third argument is.y
(#163). -
list_modify()
extendsstats::modifyList()
to replace by position if the list is not named.list_update()
useslist_modify()
(#201).update_list()
has been renamed tolist_update()
.list_merge()
operates similarly tolist_modify()
but combines instead of replacing (#322).
-
Thanks to @dchiu911, the unit test coverage of purrr is now much greater.
-
All predicate functions are re-exported from rlang (#124).
-
compact()
now works with standard mapper conventions (#282). -
cross_n()
has been renamed tocross()
. The_n
suffix was removed for consistency withpmap()
(originally calledmap_n()
at the start of the project) andtranspose()
(originally calledzip_n()
). Similarly,cross_d()
has been renamed tocross_df()
for consistency withmap_df()
. -
every()
andsome()
now returnNA
if present in the input (#174). -
invoke()
uses a more robust approach to generate the argument list (#249) It no longer uses lazyeval to figure out which enviroment a characterf
comes from. -
is_numeric()
andis_scalar_numeric()
are deprecated because they don't test for what you might naively expect. -
reduce()
now throws an error if.x
is empty and.init
is not supplied. -
Deprecated functions
flatmap()
,map3()
,map_n()
,walk3()
,walk_n()
,zip2()
,zip3()
,zip_n()
have been removed. -
pmap()
coerces data frames to lists to avoid the expensive[.data.frame
which provides security that is unneeded here (#220). -
rdunif()
checks its inputs for validity (#211). -
set_names()
can now take a function to tranform the names programmatically (#276), and you can supply names in...
to reduce typing even more more (#316).set_names()
is now powered byrlang::set_names()
. -
safely()
now actually uses thequiet
argument (#296). -
transpose()
now matches by name if available (#164). You can override the default choice with the new.names
argument.
This is a compatibility release with dplyr 0.6.0.
- All data-frame based mappers have been removed in favour of new
functions and idioms in the tidyverse.
dmap()
,dmap_at()
,dmap_if()
,invoke_rows()
,slice_rows()
,map_rows()
,by_slice()
,by_row()
, andunslice()
have been moved to purrrlyr. This is a bit of an aggresive change but it allows us to make the dependencies much lighter.
-
Fix for dev tibble support.
-
as_function()
now supports list arguments which allow recursive indexing using either names or positions. They now always stop when encountering the first NULL (#173). -
accumulate
andreduce
correctly pass extra arguments to the worker function.
-
as_function()
gains a.null
argument that for character and numeric values allows you to specify what to return for null/absent elements (#110). This can be used with any map function, e.g.map_int(x, 1, .null = NA)
-
as_function()
is now generic. -
New
is_function()
that returnsTRUE
only for regular functions. -
Fix crash on GCC triggered by
invoke_rows()
.
-
There are two handy infix functions:
x %||% y
is shorthand forif (is.null(x)) y else x
(#109).x %@% "a"
is shorthand forattr(x, "a", exact = TRUE)
(#69).
-
accumulate()
has been added to handle recursive folding. It is shortand forReduce(f, .x, accumulate = TRUE)
and follows a similar syntax toreduce()
(#145). A right-hand versionaccumulate_right()
was also added. -
map_df()
row-binds output together. It's the equivalent ofplyr::ldply()
(#127) -
flatten()
is now type-stable and always returns a list. To return a simpler vector, useflatten_lgl()
,flatten_int()
,flatten_dbl()
,flatten_chr()
, orflatten_df()
. -
invoke()
has been overhauled to be more useful: it now works similarly tomap_call()
when.x
is NULL, and hencemap_call()
has been deprecated.invoke_map()
is a vectorised complement toinvoke()
(#125), and comes with typed variantsinvoke_map_lgl()
,invoke_map_int()
,invoke_map_dbl()
,invoke_map_chr()
, andinvoke_map_df()
. -
transpose()
replaceszip2()
,zip3()
, andzip_n()
(#128). The name more clearly reflects the intent (transposing the first and second levels of list). It no longer has fields argument or the.simplify
argument; instead use the newsimplify_all()
function. -
safely()
,quietly()
, andpossibly()
are experimental functions for working with functions with side-effects (e.g. printed output, messages, warnings, and errors) (#120).safely()
is a version oftry()
that modifies a function (rather than an expression), and always returns a list with two components,result
anderror
. -
list_along()
andrep_along()
generalise the idea ofseq_along()
. (#122). -
is_null()
is the snake-case version ofis.null()
. -
pmap()
(parallel map) replacesmap_n()
(#132), and has typed-variants suffixedpmap_lgl()
,pmap_int()
,pmap_dbl()
,pmap_chr()
, andpmap_df()
. -
set_names()
is a snake-case alternative tosetNames()
with stricter equality checking, and more convenient defaults for pipes:x %>% set_names()
is equivalent tosetNames(x, x)
(#119).
We are still figuring out what belongs in dplyr and what belongs in purrr. Expect much experimentation and many changes with these functions.
-
map()
now always returns a list. Data frame support has been moved tomap_df()
anddmap()
. The latter supports sliced data frames as a shortcut for the combination ofby_slice()
anddmap()
:x %>% by_slice(dmap, fun, .collate = "rows")
. The conditional variantsdmap_at()
anddmap_if()
also support sliced data frames and will recycle scalar results to the slice size. -
map_rows()
has been renamed toinvoke_rows()
. As other rows-based functionals, it collates results inside lists by default, but with column collation this function is equivalent toplyr::mdply()
. -
The rows-based functionals gain a
.to
option to name the output column as well as a.collate
argument. The latter allows to collate the output in lists (by default), on columns or on rows. This makes these functions more flexible and more predictable.
-
as_function()
, which converts formulas etc to functions, is now exported (#123). -
rerun()
is correctly scoped (#95) -
update_list()
can now modify an element calledx
(#98). -
map*()
now use custom C code, rather than relying onlapply()
,mapply()
etc. The performance characteristcs are very similar, but it allows us greater control over the output (#118). -
map_lgl()
now has second argument.f
, not.p
(#134).
-
flatmap()
-> usemap()
followed by the appropriateflatten()
. -
map_call()
->invoke()
. -
map_n()
->pmap()
;walk_n()
->pwalk()
. -
map3(x, y, z)
->map_n(list(x, y, z))
;walk3(x, y, z) ->
pwalk(list(x, y, z))`