check_arg: Check Argument Types and Return Type

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

Description

These functions are not designed to be used directly, we advise to use the syntaxes described in ?declare instead. check_arg checks that arguments satisfy an assertion, and if relevant make them into active bindings to make sure they always satisy it. check_output checks that the value, presumably a return value, satisfies an assertion,

Usage

check_output(.output, .assertion, ...)

check_arg(.arg, .assertion, ..., .bind = FALSE)

Arguments

.output	function output
.assertion	an assertion
...	additional arguments passed to assertion
.arg	function argument
.bind	whether to actively bind the argument so it cannot be modified unless it satisfies the assertion

Value

.outputif it satisfies the assertion, fails otherwise.

returns NULL invisibly, called for side effects.

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