Last active
July 8, 2019 01:37
-
-
Save mlhaufe/089004abd14ad8e7171e2a122198637f to your computer and use it in GitHub Desktop.
Simulating Generics w/ Inheritance in TypeScript.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
abstract class Comparable { | |
abstract le(other: this): boolean | |
min(other: this): Comparable { | |
return this.le(other) ? this : other | |
} | |
} | |
abstract class Ring { | |
constructor( | |
readonly zero: Ring, | |
readonly unit: Ring | |
) {} | |
abstract plus(other: Ring): Ring | |
abstract times(other: Ring): Ring | |
} | |
/////////////// | |
class NumberComparable extends Comparable { | |
constructor (readonly value: number){ super() } | |
le(other: this): boolean { return this.value <= other.value } | |
} | |
class StringComparable extends Comparable { | |
constructor (readonly value: string){ super() } | |
le(other: this): boolean { return this.value <= other.value } | |
} | |
var n1 = new NumberComparable(7), | |
n2 = new NumberComparable(12); | |
var s1 = new StringComparable('a'), | |
s2 = new StringComparable('d') | |
n1.le(n2) | |
// s1.le(n1) //type error | |
abstract class Matrix { | |
abstract readonly of: Ring | |
protected _implementation: this['of'][][] = [] | |
getEntry(i: number, j: number): this['of'] { | |
return this._implementation[i][j] | |
} | |
setEntry(i: number, j: number, value: this['of']): this { | |
this._implementation[i][j] = value | |
return this | |
} | |
plus(other: this): this { | |
// ... | |
return this | |
} | |
times(other: this): this { | |
// ... | |
return this | |
} | |
} | |
class BoolRing extends Ring { | |
constructor(readonly value: boolean){ super(new BoolRing(false),new BoolRing(true)) } | |
plus(other: this): BoolRing { return new BoolRing(this.value || other.value) } | |
times(other: this): BoolRing { return new BoolRing(this.value && other.value) } | |
} | |
class BoolMatrix extends Matrix { of!: BoolRing } | |
var b = new BoolMatrix() | |
class NumRing extends Ring { | |
constructor(readonly value: number){ super(new NumRing(0),new NumRing(1)) } | |
plus(other: this): NumRing { return new NumRing(this.value + other.value) } | |
times(other: this): NumRing { return new NumRing(this.value * other.value) } | |
} | |
class NumMatrix extends Matrix { of!: NumRing } | |
var n = new NumMatrix() | |
abstract class Queueable { abstract of: any } | |
abstract class Queue { | |
abstract readonly of: Queueable | |
protected _implementation: this['of'][] = [] | |
isEmpty(): boolean { return this._implementation.length == 0 } | |
enqueue(element: this['of']): this { | |
this._implementation.push(element) | |
return this | |
} | |
dequeue(): this['of'] | undefined { | |
return this._implementation.shift() | |
} | |
size(): number { return this._implementation.length } | |
} | |
class QueueableString extends Queueable { | |
of!: string | |
constructor(readonly value: string) { super() } | |
} | |
class StringQueue extends Queue { of!: QueueableString } | |
class QueueableNumber extends Queueable { | |
of!: number | |
constructor(readonly value: number){ super() } | |
} | |
class NumberQueue extends Queue { of!: QueueableNumber } |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Inspired by Bertrand Meyer's 1988 book: "Object-oriented Software Construction"