assertion_factories: Assertion factories of package 'typed'

In typed: Support Types for Variables, Arguments, and Return Values

Description

These functions are assertion factories, they produce assertions, which take an object, check conditions, and returns the input, usually unmodified (never modified with the functions documented on this page).

Usage

Any(length, ...)

Logical(length, null_ok = FALSE, ...)

Integer(length, null_ok = FALSE, ...)

Double(length, null_ok = FALSE, ...)

Character(length, null_ok = FALSE, ...)

Raw(length, null_ok = FALSE, ...)

List(length, each, data_frame_ok, null_ok = FALSE, ...)

Null(...)

Closure(null_ok = FALSE, ...)

Special(null_ok = FALSE, ...)

Builtin(null_ok = FALSE, ...)

Environment(null_ok = FALSE, ...)

Symbol(null_ok = FALSE, ...)

Pairlist(length, each, null_ok = TRUE, ...)

Language(null_ok = FALSE, ...)

Expression(length, null_ok = FALSE, ...)

Function(null_ok = FALSE, ...)

Factor(length, levels, null_ok = FALSE, ...)

Matrix(nrow, ncol, null_ok = FALSE, ...)

Array(dim, null_ok = FALSE, ...)

Data.frame(nrow, ncol, each, null_ok = FALSE, ...)

Date(length, null_ok = FALSE, ...)

Time(length, null_ok = FALSE, ...)

Dots(length, each, ...)

Logical(length, null_ok = FALSE, ...)

Integer(length, null_ok = FALSE, ...)

Double(length, null_ok = FALSE, ...)

Character(length, null_ok = FALSE, ...)

Raw(length, null_ok = FALSE, ...)

List(length, each, data_frame_ok = TRUE, null_ok = FALSE, ...)

Null(...)

Closure(null_ok = FALSE, ...)

Special(null_ok = FALSE, ...)

Builtin(null_ok = FALSE, ...)

Environment(null_ok = FALSE, ...)

Symbol(null_ok = FALSE, ...)

Pairlist(length, each, null_ok = TRUE, ...)

Language(null_ok = FALSE, ...)

Expression(length, null_ok = FALSE, ...)

Function(null_ok = FALSE, ...)

Factor(length, levels, null_ok = FALSE, ...)

Data.frame(nrow, ncol, each, null_ok = FALSE, ...)

Matrix(nrow, ncol, null_ok = FALSE, ...)

Array(dim, null_ok = FALSE, ...)

Date(length, null_ok = FALSE, ...)

Time(length, null_ok = FALSE, ...)

Dots(length, each, ...)

Arguments

length	length of the object
...	additional conditions, see details.
null_ok	whether NULL values should be accepted, and not subjected to any further check.
each	assertion that every item must satisfy
data_frame_ok	whether data frames are to be considered as lists
levels	factor levels
nrow	number of rows
ncol	number of columns
dim	dimensions

Details

Additional conditions can be provided :

• If they are named, the name should be the name of a function to use on our object, and the value should be the expected value.

• If they are unnamed, they should be formulas, the right hand side should be a condition, using value or . as a placeholder for the latter, and the optional lhs an error message.

Any is the most general assertion factory, it doesn't check anything unless provided additional conditions through .... Others use the base is.<type> function if available, or check that the object is of the relevant type with typeof for atomic types, or check that the class of the checked value contains the relevant class.

Dots should only be used to check the dots using check_arg on list(...) or substitute(...()), which will be the case when it's called respectively with function(... = ? Dots()) and function(... = ?~ Dots())

Value

A function, and more specifically, an assertion as defined above.

Examples

## Not run: 
# fails
Integer() ? x <- 1
# equivalent to
declare("x", Integer(), value = 1)

Integer(2) ? x <- 1L

# we can use additional conditions in `...`
Integer(anyNA = FALSE) ? x <- c(1L, NA, 1L)
Integer(anyDuplicated = FALSE) ? x <- c(1L, NA, 1L)

## End(Not run)

Integer(2) ? x <- 11:12

## Not run: 
# We can also use it directly to test assertions
Integer() ? x <- 1
# equivalent to
declare("x", Integer(), value = 1)

Integer(2) ? x <- 1L

## End(Not run)

typed documentation built on March 19, 2021, 5:07 p.m.