Reference

Operator	Description
`&`	Boolean AND
`&&`	Boolean AND alternative
`[1,2,3]`	Array argument match
`[? string, number ]`	Array includes
`array`	Array type match
`array[4]`	Array length match
`Array<number>`	Array type match
`1..100`	Number in range (incl)
`1<<100`	Number in range (excl)
`_`	Extant
`!`	Falsey
`>`	Greater than
`>=`	Greater than or equals
`<`	Less than
`<=`	Less than or equals
`!`	Boolean NOT
`{ prop: string }`	Object
\|	Boolean OR
\|\|	Boolean OR alternative
`string`	Value is String
`string[4]`	String length match
`number`	Value is Number
`Number`, `String`, etc.	JavaScript types to test against
`!!`	Truthy
`<- "We found an issue"`	Error validation
`*`	Wildcard (always true)