`unknown()`

creates an expression used to signify that the value will be
specified at a later time.

unknown() is_unknown(x) has_unknowns(object)

x | An object or vector or objects to test for unknown-ness. |
---|---|

object | An object of class |

`unknown()`

returns expression value for `unknown()`

.

`is_unknown()`

returns a vector of logicals as long as `x`

that are `TRUE`

is the element of `x`

is unknown, and `FALSE`

otherwise.

`has_unknowns()`

returns a single logical indicating if the `range`

of a `param`

object has any unknown values.

# Just returns an expression unknown()#> unknown()# Of course, true! is_unknown(unknown())#> [1] TRUE#> [[1]] #> [1] 1 #> #> [[2]] #> unknown() #># The first value is known, the # second is not is_unknown(range)#> [1] FALSE TRUE#> [1] TRUE