Types which differ according to "type" or "kind"

[lazarljubenovic]

const isMorphRuleOfType = <TMorphType extends MorphType> (type: TMorphType) => {
  return (rule: MorphRuleBase<MorphType>): rule is MorphRuleBase<TMorphType> => {
    return rule.type === type
  }
}

Think of a way to quickly create this. Something like hasType('type', type).

[lazarljubenovic]

The term seems to be "discriminated unions", see here for example: https://basarat.gitbooks.io/typescript/docs/types/discriminated-unions.html