option_type

form an option type from a type

Synopsis

option_type(t: type) -> type

Description

The option_type function returns the option type of t, e.g., option_type(<int64>) is <option(int64)>. An option type is the type of an optional field, so it is useful as the type of a field in the argument to record_type.

If t is an option type, missing, or none, an error is returned.

Examples

Form a record type with an optional field

# spq
values record_type({x:<int64>,y:option_type(this)})
# input
<string>
# expected output
<{x:int64,y?:string}>