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dewey92/pt-alt.ts

Last active September 17, 2018 11:21
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Alternative Phantom Types
Raw
pt-alt.ts
class Temp<A> {
private readonly __unit__: A;
constructor(degree: number) { }
}
enum Unit { Celcius, Fahrenheit }
const isBoiling = (temp: Temp<Unit.Celcius>) => temp.degree >= 100;
const c100 = new Temp<Unit.Celcius>(100);
const f100 = new Temp<Unit.Fahrenheit>(100);
isBoiling(c100); // type-check!
isBoiling(f100); // error!
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