has
Table of Contents
Function
has — test existence of values
Synopsis
has(val: any [, ... val: any]) -> bool
Description
The has function returns false if any of its arguments are error("missing")
and otherwise returns true.
has(e) is a shortcut for !missing(e).
This function is most often used to test the existence of certain fields in an
expected record, e.g., has(a,b) is true when this is a record and has
the fields a and b, provided their values are not error("missing").
It’s also useful in shaping when applying conditional logic based on the presence of certain fields:
switch (
case has(a) => ...
case has(b) => ...
default => ...
)
Examples
yield {yes:has(foo),no:has(bar)}{foo:10}Loading...