[TypeScript]: Indexing type by two generics enums
I am trying to get the return type of a function from a type by an index, where the index is a generic type variable.
Code:
enum PROTOCOL { P1 = 0, P2 = 1 };
enum PROTOCOL_P1_SPACE { S11 = 0, S12 = 1 };
enum PROTOCOL_P2_SPACE { S21 = 0, S22 = 1 };
type OBJECT = {
[PROTOCOL.P1]: {
[PROTOCOL_P1_SPACE.S11]: { a: string },
[PROTOCOL_P1_SPACE.S12]: { b: Array<number> },
},
[PROTOCOL.P2]: {
[PROTOCOL_P2_SPACE.S21]: { c: number },
[PROTOCOL_P2_SPACE.S22]: { d: Buffer },
},
};
function getObject<
TProtocol extends PROTOCOL,
TSpace extends PROTOCOL_P1_SPACE | PROTOCOL_P2_SPACE
>(query: string): OBJECT[TProtocol][TSpace] { return call('getObject', query); };
TypeScript throws the error Type 'TSpace' cannot be used to index type 'OBJECT[TProtocol]'.
How to fix it?
P.S. VSCode can understand what i want:
const p1s1 = getObject<PROTOCOL.P1, PROTOCOL_P1_SPACE.S11>('p1s1');
const p2s1 = getObject<PROTOCOL.P2, PROTOCOL_P2_SPACE.S21>('p2s2');
It understand, that p1s1 is { a: string } and p2s1 is { c: number }
typescript typescript-typings
asked Jan 18 at 15:59
Nick LatkovichNick Latkovich
286
add a comment |
I am trying to get the return type of a function from a type by an index, where the index is a generic type variable.
Code:
enum PROTOCOL { P1 = 0, P2 = 1 };
enum PROTOCOL_P1_SPACE { S11 = 0, S12 = 1 };
enum PROTOCOL_P2_SPACE { S21 = 0, S22 = 1 };
type OBJECT = {
[PROTOCOL.P1]: {
[PROTOCOL_P1_SPACE.S11]: { a: string },
[PROTOCOL_P1_SPACE.S12]: { b: Array<number> },
},
[PROTOCOL.P2]: {
[PROTOCOL_P2_SPACE.S21]: { c: number },
[PROTOCOL_P2_SPACE.S22]: { d: Buffer },
},
};
function getObject<
TProtocol extends PROTOCOL,
TSpace extends PROTOCOL_P1_SPACE | PROTOCOL_P2_SPACE
>(query: string): OBJECT[TProtocol][TSpace] { return call('getObject', query); };
TypeScript throws the error Type 'TSpace' cannot be used to index type 'OBJECT[TProtocol]'.
How to fix it?
P.S. VSCode can understand what i want:
const p1s1 = getObject<PROTOCOL.P1, PROTOCOL_P1_SPACE.S11>('p1s1');
const p2s1 = getObject<PROTOCOL.P2, PROTOCOL_P2_SPACE.S21>('p2s2');
It understand, that p1s1 is { a: string } and p2s1 is { c: number }
typescript typescript-typings
asked Jan 18 at 15:59
Nick LatkovichNick Latkovich
286
add a comment |
I am trying to get the return type of a function from a type by an index, where the index is a generic type variable.
Code:
enum PROTOCOL { P1 = 0, P2 = 1 };
enum PROTOCOL_P1_SPACE { S11 = 0, S12 = 1 };
enum PROTOCOL_P2_SPACE { S21 = 0, S22 = 1 };
type OBJECT = {
[PROTOCOL.P1]: {
[PROTOCOL_P1_SPACE.S11]: { a: string },
[PROTOCOL_P1_SPACE.S12]: { b: Array<number> },
},
[PROTOCOL.P2]: {
[PROTOCOL_P2_SPACE.S21]: { c: number },
[PROTOCOL_P2_SPACE.S22]: { d: Buffer },
},
};
function getObject<
TProtocol extends PROTOCOL,
TSpace extends PROTOCOL_P1_SPACE | PROTOCOL_P2_SPACE
>(query: string): OBJECT[TProtocol][TSpace] { return call('getObject', query); };
TypeScript throws the error Type 'TSpace' cannot be used to index type 'OBJECT[TProtocol]'.
How to fix it?
P.S. VSCode can understand what i want:
const p1s1 = getObject<PROTOCOL.P1, PROTOCOL_P1_SPACE.S11>('p1s1');
const p2s1 = getObject<PROTOCOL.P2, PROTOCOL_P2_SPACE.S21>('p2s2');
It understand, that p1s1 is { a: string } and p2s1 is { c: number }
typescript typescript-typings
asked Jan 18 at 15:59
Nick LatkovichNick Latkovich
286
I am trying to get the return type of a function from a type by an index, where the index is a generic type variable.
Code:
enum PROTOCOL { P1 = 0, P2 = 1 };
enum PROTOCOL_P1_SPACE { S11 = 0, S12 = 1 };
enum PROTOCOL_P2_SPACE { S21 = 0, S22 = 1 };
type OBJECT = {
[PROTOCOL.P1]: {
[PROTOCOL_P1_SPACE.S11]: { a: string },
[PROTOCOL_P1_SPACE.S12]: { b: Array<number> },
},
[PROTOCOL.P2]: {
[PROTOCOL_P2_SPACE.S21]: { c: number },
[PROTOCOL_P2_SPACE.S22]: { d: Buffer },
},
};
function getObject<
TProtocol extends PROTOCOL,
TSpace extends PROTOCOL_P1_SPACE | PROTOCOL_P2_SPACE
>(query: string): OBJECT[TProtocol][TSpace] { return call('getObject', query); };
TypeScript throws the error Type 'TSpace' cannot be used to index type 'OBJECT[TProtocol]'.
How to fix it?
P.S. VSCode can understand what i want:
const p1s1 = getObject<PROTOCOL.P1, PROTOCOL_P1_SPACE.S11>('p1s1');
const p2s1 = getObject<PROTOCOL.P2, PROTOCOL_P2_SPACE.S21>('p2s2');
It understand, that p1s1 is { a: string } and p2s1 is { c: number }
typescript typescript-typings
typescript typescript-typings
asked Jan 18 at 15:59
Nick LatkovichNick Latkovich
286
asked Jan 18 at 15:59
Nick LatkovichNick Latkovich
286
asked Jan 18 at 15:59
Nick LatkovichNick Latkovich
286
asked Jan 18 at 15:59
Nick LatkovichNick Latkovich
286
asked Jan 18 at 15:59
Nick LatkovichNick Latkovich
286
286
add a comment |
add a comment |
1 Answer
1
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votes
You have to make the type of TSpace be dependent on the type of TProtocol. One way to achieve this would be like this:
function getObject<
TProtocol extends PROTOCOL,
TSpace extends keyof OBJECT[TProtocol]
>(query: string): OBJECT[TProtocol][TSpace]
answered Jan 18 at 16:10
GrassatorGrassator
80959
ty. It resolved my problem.
– Nick Latkovich
Jan 18 at 18:03
add a comment |
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1 Answer
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active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
You have to make the type of TSpace be dependent on the type of TProtocol. One way to achieve this would be like this:
function getObject<
TProtocol extends PROTOCOL,
TSpace extends keyof OBJECT[TProtocol]
>(query: string): OBJECT[TProtocol][TSpace]
answered Jan 18 at 16:10
GrassatorGrassator
80959
ty. It resolved my problem.
– Nick Latkovich
Jan 18 at 18:03
add a comment |
You have to make the type of TSpace be dependent on the type of TProtocol. One way to achieve this would be like this:
function getObject<
TProtocol extends PROTOCOL,
TSpace extends keyof OBJECT[TProtocol]
>(query: string): OBJECT[TProtocol][TSpace]
answered Jan 18 at 16:10
GrassatorGrassator
80959
ty. It resolved my problem.
– Nick Latkovich
Jan 18 at 18:03
add a comment |
You have to make the type of TSpace be dependent on the type of TProtocol. One way to achieve this would be like this:
function getObject<
TProtocol extends PROTOCOL,
TSpace extends keyof OBJECT[TProtocol]
>(query: string): OBJECT[TProtocol][TSpace]
answered Jan 18 at 16:10
GrassatorGrassator
80959
You have to make the type of TSpace be dependent on the type of TProtocol. One way to achieve this would be like this:
function getObject<
TProtocol extends PROTOCOL,
TSpace extends keyof OBJECT[TProtocol]
>(query: string): OBJECT[TProtocol][TSpace]
answered Jan 18 at 16:10
GrassatorGrassator
80959
answered Jan 18 at 16:10
GrassatorGrassator
80959
answered Jan 18 at 16:10
GrassatorGrassator
80959
answered Jan 18 at 16:10
GrassatorGrassator
80959
80959
ty. It resolved my problem.
– Nick Latkovich
Jan 18 at 18:03
add a comment |
ty. It resolved my problem.
– Nick Latkovich
Jan 18 at 18:03
ty. It resolved my problem.
– Nick Latkovich
Jan 18 at 18:03
ty. It resolved my problem.
– Nick Latkovich
Jan 18 at 18:03
add a comment |
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