Function reference • purrr

Map family The `map(.x, .f)` functions transforms each element of the vector `.x` with the function `.f`, returning a vector defined by the suffix (`_lgl`, `_chr()` etc). `walk()` is a variant for functions called primarily for their side-effects; it returns `.x` invisibly. As well as functions, `.f`, can take numbers and characters (used as a shorthand for `[[`), and formulas (used as a succint function definition). See details in `as_mapper()`
`map()` `map_lgl()` `map_chr()` `map_int()` `map_dbl()` `map_raw()` `map_dfr()` `map_dfc()` `walk()`	Apply a function to each element of a list or atomic vector
`as_mapper()`	Convert an object into a mapper function
Map variants A rich set of variants builds on the basic idea of `map()`: `modify()` modifies “in place”, returning a vector the same type as `.x`; `map2()` iterates over two vectors in parallel; `pmap()` (parallel map) iterates over a list of vectors; `imap()` (index map) is a shortcut for the common pattern `map2(x, names(x))`.
`map2()` `map2_lgl()` `map2_int()` `map2_dbl()` `map2_chr()` `map2_raw()` `map2_dfr()` `map2_dfc()` `walk2()` `pmap()` `pmap_lgl()` `pmap_int()` `pmap_dbl()` `pmap_chr()` `pmap_raw()` `pmap_dfr()` `pmap_dfc()` `pwalk()`	Map over multiple inputs simultaneously.
`modify()` `modify_if()` `modify_at()` `modify2()` `imodify()` `modify_depth()`	Modify elements selectively
`imap()` `imap_lgl()` `imap_chr()` `imap_int()` `imap_dbl()` `imap_raw()` `imap_dfr()` `imap_dfc()` `iwalk()`	Apply a function to each element of a vector, and its index
`lmap()` `lmap_if()` `lmap_at()`	Apply a function to list-elements of a list
Predicate functionals A predicate function is a function that either returns `TRUE` or `FALSE`. The predicate functionals take a vector and a predicate function and do something useful.
`detect()` `detect_index()`	Find the value or position of the first match
`every()` `some()` `none()`	Do every, some, or none of the elements of a list satisfy a predicate?
`has_element()`	Does a list contain an object?
`head_while()` `tail_while()`	Find head/tail that all satisfies a predicate.
`keep()` `discard()` `compact()`	Keep or discard elements using a predicate function.
`negate()`	Negate a predicate function.
`prepend()`	Prepend a vector
Plucking Getting or setting a single element.
`pluck()` `chuck()` `pluck<-`()	Pluck or chuck a single element from a vector or environment
`modify_in()` `assign_in()`	Modify a pluck location
`attr_getter()`	Create an attribute getter function
`%@%`	Infix attribute accessor
Other vector transforms A grab bag of useful tools for manipulating vectors.
`accumulate()` `accumulate2()`	Accumulate intermediate results of a vector reduction
`cross()` `cross2()` `cross3()` `cross_df()`	Produce all combinations of list elements
`flatten()` `flatten_lgl()` `flatten_int()` `flatten_dbl()` `flatten_chr()` `flatten_raw()` `flatten_dfr()` `flatten_dfc()`	Flatten a list of lists into a simple vector.
`list_modify()` `list_merge()`	Modify a list
`reduce()` `reduce2()`	Reduce a list to a single value by iteratively applying a binary function
`splice()`	Splice objects and lists of objects into a list
`transpose()`	Transpose a list.
Adverbs Adverbs modify the action of a function; taking a function as input and returning a function with modified action as output.
`compose()`	Compose multiple functions
`lift()` `lift_dl()` `lift_dv()` `lift_vl()` `lift_vd()` `lift_ld()` `lift_lv()`	Lift the domain of a function
`negate()`	Negate a predicate function.
`partial()`	Partial apply a function, filling in some arguments.
`safely()` `quietly()` `possibly()` `auto_browse()`	Capture side effects.
`insistently()` `slowly()`	Transform a function to make it run insistently or slowly
`rate_sleep()` `rate_reset()`	Wait for a given time
`rate_delay()` `rate_backoff()` `is_rate()`	Create delaying rate settings
Misc
`null-default`	Default value for `NULL`
`array_branch()` `array_tree()`	Coerce array to list
`as_vector()` `simplify()` `simplify_all()`	Coerce a list to a vector
`rbernoulli()`	Generate random sample from a Bernoulli distribution
`rdunif()`	Generate random sample from a discrete uniform distribution
`rerun()`	Re-run expressions multiple times.
`set_names`	Set names in a vector
`vec_depth()`	Compute the depth of a vector

Reference

Map family

Map variants

Predicate functionals

Plucking

Other vector transforms

Adverbs

Misc