4 ms·

Slow compile times are very much a problem caused by TypeScript.

by jorams 6y ago

eitland 6y ago
My 3 year old laptop has no problems with TypeScript (neither Angular nor React), and I am a rather impatient guy when it comes to computers. I'm honestly wondering: What are people doing to end up in a position where TypeScript compile times are a problem?
- austincheney 6y ago
 It is something to do with a class in their code named something similar to header conflicting with a same named definition in their index.d.ts file that is closely related to that class instance. If they dropped use of classes, or differentiated the names of the two things in collision the problem would appear to be solved. To turn that around and blame TypeScript as the point of failure is an extremely bad omen suggesting their code style opinions are more important than product delivery. I could live with that nonsense if this were a framework or some minor dependency, which this application is not.
- thomasrognon 6y ago
 My compile time went from seconds to minutes when I made a recursive immutable type (which I reverted of course). Overall, I still love typescript. Edit for the curious, here's the monster type that caused such pathological build times... type ImmutablePrimitive = undefined | null | boolean | string | number | Function; export type Immutable<T> = T extends ImmutablePrimitive ? T : T extends [infer U] ? readonly [Immutable] : T extends [infer U, infer V] ? readonly [Immutable, Immutable<V>] : T extends [infer U, infer V, infer X] ? readonly [Immutable, Immutable<V>, Immutable<X>] : T extends [infer U, infer V, infer X, infer Y] ? readonly [Immutable, Immutable<V>, Immutable<X>, Immutable<Y>] : T extends [infer U, infer V, infer X, infer Y, infer Z] ? readonly [Immutable, Immutable<V>, Immutable<X>, Immutable<Y>, Immutable<Z>] : T extends readonly [infer U] ? readonly [Immutable] : T extends readonly [infer U, infer V] ? readonly [Immutable, Immutable<V>] : T extends readonly [infer U, infer V, infer X] ? readonly [Immutable, Immutable<V>, Immutable<X>] : T extends readonly [infer U, infer V, infer X, infer Y] ? readonly [Immutable, Immutable<V>, Immutable<X>, Immutable<Y>] : T extends readonly [infer U, infer V, infer X, infer Y, infer Z] ? readonly [Immutable, Immutable<V>, Immutable<X>, Immutable<Y>, Immutable<Z>] : T extends Array<infer U> ? ImmutableArray : T extends ReadonlyArray<infer U> ? ImmutableArray : T extends Map<infer K, infer V> ? ImmutableMap<K, V> : T extends ReadonlyMap<infer K, infer V> ? ImmutableMap<K, V> : T extends Set<infer M> ? ImmutableSet<M> : T extends ReadonlySet<infer M> ? ImmutableSet<M> : ImmutableObject<T>; type ImmutableArray<T> = ReadonlyArray<Immutable<T>>; type ImmutableMap<K, V> = ReadonlyMap<Immutable<K>, Immutable<V>>; type ImmutableSet<T> = ReadonlySet<Immutable<T>>; type ImmutableObject<T> = { readonly [K in keyof T]: Immutable<T[K]> };
austincheney 6y ago
You can do any manner of stupid things to make any compiler of any language to behave slowly, but that doesn’t mean all compilers are slow. If you want better output don’t deliver garbage for input.

Slow compile times are very much a problem caused by TypeScript.

by jorams 6y ago

Slow compile times are very much a problem caused by TypeScript.

My 3 year old laptop has no problems with TypeScript (neither Angular nor React), and I am a rather impatient guy when it comes to computers. I'm honestly wondering: What are people doing to end up in a position where TypeScript compile times are a problem?

austincheney 6y ago
It is something to do with a class in their code named something similar to header conflicting with a same named definition in their index.d.ts file that is closely related to that class instance. If they dropped use of classes, or differentiated the names of the two things in collision the problem would appear to be solved. To turn that around and blame TypeScript as the point of failure is an extremely bad omen suggesting their code style opinions are more important than product delivery. I could live with that nonsense if this were a framework or some minor dependency, which this application is not.
thomasrognon 6y ago
My compile time went from seconds to minutes when I made a recursive immutable type (which I reverted of course). Overall, I still love typescript. Edit for the curious, here's the monster type that caused such pathological build times... type ImmutablePrimitive = undefined | null | boolean | string | number | Function; export type Immutable<T> = T extends ImmutablePrimitive ? T : T extends [infer U] ? readonly [Immutable] : T extends [infer U, infer V] ? readonly [Immutable, Immutable<V>] : T extends [infer U, infer V, infer X] ? readonly [Immutable, Immutable<V>, Immutable<X>] : T extends [infer U, infer V, infer X, infer Y] ? readonly [Immutable, Immutable<V>, Immutable<X>, Immutable<Y>] : T extends [infer U, infer V, infer X, infer Y, infer Z] ? readonly [Immutable, Immutable<V>, Immutable<X>, Immutable<Y>, Immutable<Z>] : T extends readonly [infer U] ? readonly [Immutable] : T extends readonly [infer U, infer V] ? readonly [Immutable, Immutable<V>] : T extends readonly [infer U, infer V, infer X] ? readonly [Immutable, Immutable<V>, Immutable<X>] : T extends readonly [infer U, infer V, infer X, infer Y] ? readonly [Immutable, Immutable<V>, Immutable<X>, Immutable<Y>] : T extends readonly [infer U, infer V, infer X, infer Y, infer Z] ? readonly [Immutable, Immutable<V>, Immutable<X>, Immutable<Y>, Immutable<Z>] : T extends Array<infer U> ? ImmutableArray : T extends ReadonlyArray<infer U> ? ImmutableArray : T extends Map<infer K, infer V> ? ImmutableMap<K, V> : T extends ReadonlyMap<infer K, infer V> ? ImmutableMap<K, V> : T extends Set<infer M> ? ImmutableSet<M> : T extends ReadonlySet<infer M> ? ImmutableSet<M> : ImmutableObject<T>; type ImmutableArray<T> = ReadonlyArray<Immutable<T>>; type ImmutableMap<K, V> = ReadonlyMap<Immutable<K>, Immutable<V>>; type ImmutableSet<T> = ReadonlySet<Immutable<T>>; type ImmutableObject<T> = { readonly [K in keyof T]: Immutable<T[K]> };

austincheney 6y ago

You can do any manner of stupid things to make any compiler of any language to behave slowly, but that doesn’t mean all compilers are slow. If you want better output don’t deliver garbage for input.