Refer to a struct by name

Lets a struct refer to itself, or to one that is defined later. The name is resolved on first use and then cached, so redefining a struct in a live session cannot silently retype the structs that already refer to it.

Usage

ref(name)

Arguments

name

The struct's name.

Value

A type.

See also

opt() for the common ref(name) | NULL case.

Examples

Node <- struct("Node", value = int[1], next_ = opt("Node"))
Node(value = 1, next_ = list(value = 2))
#> <Node>
#>   value : 1L
#>   next_ : <Node>

try(parse_as(ref("NeverDefined"), list()))
#> Error : unknown struct `NeverDefined`: define it with struct("NeverDefined", ...) before validating