Condition.ceylon
"A condition.
There are four kinds of conditions:
- a [[boolean condition|BooleanCondition]] is satisfied when a boolean expression evaluates to [[true]],
- an [[assignability condition|IsCondition]] is satisfied when a value satisfies a specified type,
- an [[existence condition|ExistsCondition]] is satisfied when a value is not [[null]], and
- a [[nonemptiness condition|NonemptyCondition]] is satisfied when a [[sequential|Sequential]] value is not [[null]] and not [[empty]].
Examples:
exists first = string.first
type in { type_ws, type_comment }
is Float number
nonempty members"
shared abstract class Condition()
of BooleanCondition | IsCondition | ExistsOrNonemptyCondition
extends Node() {
}