Function reference • rlang

Tidy evaluation Quote arguments and expressions with unquoting support. The quosure variants wrap an environment with the expression.
`expr()` `enexpr()` `exprs()` `enexprs()` `ensym()` `ensyms()` `quo()` `enquo()` `quos()` `enquos()`	Defuse R expressions
`qq_show()`	Force parts of an expression
`as_label()`	Create a default name for an R object
`as_name()`	Extract names from symbols
Tidy dots Collect arguments contained in `...` with `!!!` and name-unquoting support.
`dyn-dots`	Dynamic dots
`list2()` `dots_list()`	Collect dots in a list
`pairlist2()`	Create pairlists with splicing support
Errors, conditions, and backtraces
`abort()` `warn()` `inform()` `signal()` `interrupt()`	Signal an error, warning, or message
`cnd_message()` `cnd_header()` `cnd_body()` `cnd_footer()`	Build an error message from parts
`format_error_bullets()`	Format bullets for error messages
`trace_back()` `trace_length()`	Capture a backtrace
`with_abort()`	Promote all errors to rlang errors
`entrace()` `cnd_entrace()`	Add backtrace from error handler
`cnd_signal()`	Signal a condition object
`last_error()` `last_trace()`	Last `abort()` error
`rlang_backtrace_on_error`	Display backtrace on error
`catch_cnd()`	Catch a condition
Evaluate expressions
`eval_tidy()`	Evaluate an expression with quosures and pronoun support
`eval_bare()`	Evaluate an expression in an environment
`exec()`	Execute a function
Symbols
`sym()` `syms()`	Create a symbol or list of symbols
`is_symbol()`	Is object a symbol?
`as_string()`	Cast symbol to string
Calls
`call_args()` `call_args_names()`	Extract arguments from a call
`call_fn()`	Extract function from a call
`call_inspect()`	Inspect a call
`call_modify()`	Modify the arguments of a call
`call_name()` `call_ns()`	Extract function name or namespace of a call
`call_standardise()`	Standardise a call
`call2()`	Create a call
`is_call()`	Is object a call?
Expressions
`expr_interp()`	Process unquote operators in a captured expression
`expr_label()` `expr_name()` `expr_text()`	Turn an expression to a label
`expr_print()` `expr_deparse()`	Print an expression
`exprs_auto_name()` `quos_auto_name()`	Ensure that all elements of a list of expressions are named
`parse_expr()` `parse_exprs()` `parse_quo()` `parse_quos()`	Parse R code
`is_expression()` `is_syntactic_literal()` `is_symbolic()`	Is an object an expression?
`set_expr()` `get_expr()`	Set and get an expression
Quosures
`quo_label()` `quo_text()` `quo_name()`	Format quosures for printing or labelling
`quo_squash()`	Squash a quosure
`is_quosure()` `quo_is_missing()` `quo_is_symbol()` `quo_is_call()` `quo_is_symbolic()` `quo_is_null()` `quo_get_expr()` `quo_get_env()` `quo_set_expr()` `quo_set_env()`	Quosure getters, setters and testers
`as_quosure()` `new_quosure()`	Coerce object to quosure
`new_quosures()` `as_quosures()` `is_quosures()`	Create a list of quosures
`exprs_auto_name()` `quos_auto_name()`	Ensure that all elements of a list of expressions are named
Formulas
`f_rhs()` `f_rhs<-`() `f_lhs()` `f_lhs<-`() `f_env()` `f_env<-`()	Get or set formula components
`f_text()` `f_name()` `f_label()`	Turn RHS of formula into a string or label
`new_formula()`	Create a formula
`is_formula()` `is_bare_formula()`	Is object a formula?
Functions
`fn_body()` `fn_body<-`()	Get or set function body
`fn_env()` `fn_env<-`()	Return the closure environment of a function
`fn_fmls()` `fn_fmls_names()` `fn_fmls_syms()` `fn_fmls<-`() `fn_fmls_names<-`()	Extract arguments from a function
`new_function()`	Create a function
`is_function()` `is_closure()` `is_primitive()` `is_primitive_eager()` `is_primitive_lazy()`	Is object a function?
`as_function()` `is_lambda()` `as_closure()`	Convert to function or closure
Environments
`env()` `child_env()` `new_environment()`	Create a new environment
`env_print()`	Pretty-print an environment
`env_parent()` `env_tail()` `env_parents()`	Get parent environments
`env_depth()`	Depth of an environment chain
`get_env()` `set_env()` `env_poke_parent()`	Get or set the environment of an object
`env_clone()`	Clone an environment
`env_inherits()`	Does environment inherit from another environment?
`is_environment()` `is_bare_environment()`	Is object an environment?
`as_environment()`	Coerce to an environment
`caller_env()` `current_env()`	Get the current or caller environment
Environment bindings
`env_bind()` `env_bind_lazy()` `env_bind_active()` `%<~%`	Bind symbols to objects in an environment
`env_unbind()`	Remove bindings from an environment
`env_poke()`	Poke an object in an environment
`local_bindings()` `with_bindings()`	Temporarily change bindings of an environment
`scoped_interactive()` `scoped_options()` `scoped_bindings()`	Questioning `scoped_` functions
`env_has()`	Does an environment have or see bindings?
`env_get()` `env_get_list()`	Get an object in an environment
`env_names()` `env_length()`	Names and numbers of symbols bound in an environment
Search path and namespaces
`search_envs()` `search_env()` `pkg_env()` `pkg_env_name()` `is_attached()` `base_env()` `global_env()`	Search path environments
`empty_env()`	Get the empty environment
`is_installed()` `check_installed()`	Are packages installed in any of the libraries?
`is_namespace()`	Is an object a namespace environment?
`ns_env()` `ns_imports_env()` `ns_env_name()`	Get the namespace of a package
`env_name()` `env_label()`	Label of an environment
S3
`inherits_any()` `inherits_all()` `inherits_only()`	Does an object inherit from a set of classes?
`new_box()` `is_box()` `unbox()`	Box a value
`as_box()` `as_box_if()`	Convert object to a box
`zap()` `is_zap()`	Create zap objects
`done()` `is_done_box()`	Box a final value for early termination
Create vectors Atomic vector constructors have implicit splicing (i.e. splice lists automatically), while the list constructor has explicit splicing.
`lgl()` `int()` `dbl()` `cpl()` `chr()` `bytes()`	Create vectors
`list2()` `dots_list()`	Collect dots in a list
`rep_along()` `rep_named()`	Create vectors matching the length of a given vector
`seq2()` `seq2_along()`	Increasing sequence of integers in an interval
Attributes
`set_names()`	Set names of a vector
`names2()`	Get names of a vector
`has_name()`	Does an object have an element with this name?
`is_named()` `is_dictionaryish()` `have_name()`	Is object named?
Type predicates
`is_list()` `is_atomic()` `is_vector()` `is_integer()` `is_double()` `is_character()` `is_logical()` `is_raw()` `is_bytes()` `is_null()`	Type predicates
`is_scalar_list()` `is_scalar_atomic()` `is_scalar_vector()` `is_scalar_integer()` `is_scalar_double()` `is_scalar_character()` `is_scalar_logical()` `is_scalar_raw()` `is_string()` `is_scalar_bytes()` `is_bool()`	Scalar type predicates
`is_bare_list()` `is_bare_atomic()` `is_bare_vector()` `is_bare_double()` `is_bare_integer()` `is_bare_numeric()` `is_bare_character()` `is_bare_logical()` `is_bare_raw()` `is_bare_string()` `is_bare_bytes()`	Bare type predicates
`is_empty()`	Is object an empty vector or NULL?
`is_integerish()` `is_bare_integerish()` `is_scalar_integerish()`	Is a vector integer-like?
`is_true()` `is_false()`	Is object identical to TRUE or FALSE?
Operators
`%\|\|%`	Default value for `NULL`
`%\|%`	Replace missing values
`%@%` `%@%<-`()	Infix attribute accessor and setter
Function arguments
`arg_match()` `arg_match0()`	Match an argument to a character vector
`missing_arg()` `is_missing()` `maybe_missing()`	Generate or handle a missing argument
Create tidy evaluation APIs Create data masking APIs à-la dplyr or tidyr. These functions are meant for developers rather than users.
`.data` `.env`	Data pronouns for tidy evaluation
`eval_tidy()`	Evaluate an expression with quosures and pronoun support
`as_data_mask()` `as_data_pronoun()` `new_data_mask()`	Create a data mask
Condition handlers
`with_handlers()` `calling()`	Establish handlers on the stack
Session state
`is_interactive()` `local_interactive()` `with_interactive()`	Is R running interactively?
`scoped_interactive()` `scoped_options()` `scoped_bindings()`	Questioning `scoped_` functions
`faq-options`	Global options for rlang
`local_options()` `with_options()` `push_options()` `peek_options()` `peek_option()`	Change global options
Weak references
`is_weakref()`	Is object a weak reference?
`new_weakref()`	Create a weak reference
`wref_key()` `wref_value()`	Get key/value from a weak reference object
FAQ
`faq-options`	Global options for rlang

Reference

Tidy evaluation

Tidy dots

Errors, conditions, and backtraces

Evaluate expressions

Symbols

Calls

Expressions

Quosures

Formulas

Functions

Environments

Environment bindings

Search path and namespaces

S3

Create vectors

Attributes

Type predicates

Operators

Function arguments

Create tidy evaluation APIs

Condition handlers

Session state

Weak references

FAQ