Two functions with same arguments but different return type
I have a function that takes two functions as arguments (fn1 and fn2). These functions should take the same arbitrary number of arguments with the same types but different return types.
Is there a way to make sure the argument types of the functions are the same?
function myFunction(fn1: Function, fn2: (...args: any) => string): number {
return 0;
}
function typescript generics
asked Nov 12 at 11:38
dotjpg3141
1007
add a comment |
I have a function that takes two functions as arguments (fn1 and fn2). These functions should take the same arbitrary number of arguments with the same types but different return types.
Is there a way to make sure the argument types of the functions are the same?
function myFunction(fn1: Function, fn2: (...args: any) => string): number {
return 0;
}
function typescript generics
asked Nov 12 at 11:38
dotjpg3141
1007
Any return type? Or two types specified bymyFunction?
– Titian Cernicova-Dragomir
Nov 12 at 11:53
The return type of the first function can have any type. The return type of the second function is always string.
– dotjpg3141
Nov 12 at 11:55
add a comment |
I have a function that takes two functions as arguments (fn1 and fn2). These functions should take the same arbitrary number of arguments with the same types but different return types.
Is there a way to make sure the argument types of the functions are the same?
function myFunction(fn1: Function, fn2: (...args: any) => string): number {
return 0;
}
function typescript generics
asked Nov 12 at 11:38
dotjpg3141
1007
I have a function that takes two functions as arguments (fn1 and fn2). These functions should take the same arbitrary number of arguments with the same types but different return types.
Is there a way to make sure the argument types of the functions are the same?
function myFunction(fn1: Function, fn2: (...args: any) => string): number {
return 0;
}
function typescript generics
function typescript generics
asked Nov 12 at 11:38
dotjpg3141
1007
asked Nov 12 at 11:38
dotjpg3141
1007
asked Nov 12 at 11:38
dotjpg3141
1007
asked Nov 12 at 11:38
dotjpg3141
1007
asked Nov 12 at 11:38
dotjpg3141
1007
1007
Any return type? Or two types specified bymyFunction?
– Titian Cernicova-Dragomir
Nov 12 at 11:53
The return type of the first function can have any type. The return type of the second function is always string.
– dotjpg3141
Nov 12 at 11:55
add a comment |
Any return type? Or two types specified bymyFunction?
– Titian Cernicova-Dragomir
Nov 12 at 11:53
The return type of the first function can have any type. The return type of the second function is always string.
– dotjpg3141
Nov 12 at 11:55
Any return type? Or two types specified by
myFunction?– Titian Cernicova-Dragomir
Nov 12 at 11:53
Any return type? Or two types specified by
myFunction?– Titian Cernicova-Dragomir
Nov 12 at 11:53
The return type of the first function can have any type. The return type of the second function is always string.
– dotjpg3141
Nov 12 at 11:55
The return type of the first function can have any type. The return type of the second function is always string.
– dotjpg3141
Nov 12 at 11:55
add a comment |
1 Answer
1
active
oldest
votes
You can use conditional types and tuples in rest parameters to extract the arguments types from the first function and specify the second function in terms of the extracted arguments
type ArgTypes<T> = T extends (...a:infer A) => unknown?A:
function myFunction<T extends (...a: unknown) => unknown>(fn1: T, fn2: (...a: ArgTypes<T>) => string) :number {
return 0;
}
myFunction((s: string) => s, (s:string) => s) //ok
myFunction((s: string) => s, (s:number) => s.toString()) //err
answered Nov 12 at 11:58
Titian Cernicova-Dragomir
55.8k33452
function myFunction<T extends Function>(fn1: T, fn2: (...a: ArgTypes<T>) => string) :numbershould also work
– dotjpg3141
Nov 12 at 12:13
@dotjpg3141 I avoid usingFunctiondirectly .. but yeah that should also work :)
– Titian Cernicova-Dragomir
Nov 12 at 12:17
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53261378%2ftwo-functions-with-same-arguments-but-different-return-type%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
You can use conditional types and tuples in rest parameters to extract the arguments types from the first function and specify the second function in terms of the extracted arguments
type ArgTypes<T> = T extends (...a:infer A) => unknown?A:
function myFunction<T extends (...a: unknown) => unknown>(fn1: T, fn2: (...a: ArgTypes<T>) => string) :number {
return 0;
}
myFunction((s: string) => s, (s:string) => s) //ok
myFunction((s: string) => s, (s:number) => s.toString()) //err
answered Nov 12 at 11:58
Titian Cernicova-Dragomir
55.8k33452
function myFunction<T extends Function>(fn1: T, fn2: (...a: ArgTypes<T>) => string) :numbershould also work
– dotjpg3141
Nov 12 at 12:13
@dotjpg3141 I avoid usingFunctiondirectly .. but yeah that should also work :)
– Titian Cernicova-Dragomir
Nov 12 at 12:17
add a comment |
You can use conditional types and tuples in rest parameters to extract the arguments types from the first function and specify the second function in terms of the extracted arguments
type ArgTypes<T> = T extends (...a:infer A) => unknown?A:
function myFunction<T extends (...a: unknown) => unknown>(fn1: T, fn2: (...a: ArgTypes<T>) => string) :number {
return 0;
}
myFunction((s: string) => s, (s:string) => s) //ok
myFunction((s: string) => s, (s:number) => s.toString()) //err
answered Nov 12 at 11:58
Titian Cernicova-Dragomir
55.8k33452
function myFunction<T extends Function>(fn1: T, fn2: (...a: ArgTypes<T>) => string) :numbershould also work
– dotjpg3141
Nov 12 at 12:13
@dotjpg3141 I avoid usingFunctiondirectly .. but yeah that should also work :)
– Titian Cernicova-Dragomir
Nov 12 at 12:17
add a comment |
You can use conditional types and tuples in rest parameters to extract the arguments types from the first function and specify the second function in terms of the extracted arguments
type ArgTypes<T> = T extends (...a:infer A) => unknown?A:
function myFunction<T extends (...a: unknown) => unknown>(fn1: T, fn2: (...a: ArgTypes<T>) => string) :number {
return 0;
}
myFunction((s: string) => s, (s:string) => s) //ok
myFunction((s: string) => s, (s:number) => s.toString()) //err
answered Nov 12 at 11:58
Titian Cernicova-Dragomir
55.8k33452
You can use conditional types and tuples in rest parameters to extract the arguments types from the first function and specify the second function in terms of the extracted arguments
type ArgTypes<T> = T extends (...a:infer A) => unknown?A:
function myFunction<T extends (...a: unknown) => unknown>(fn1: T, fn2: (...a: ArgTypes<T>) => string) :number {
return 0;
}
myFunction((s: string) => s, (s:string) => s) //ok
myFunction((s: string) => s, (s:number) => s.toString()) //err
answered Nov 12 at 11:58
Titian Cernicova-Dragomir
55.8k33452
answered Nov 12 at 11:58
Titian Cernicova-Dragomir
55.8k33452
answered Nov 12 at 11:58
Titian Cernicova-Dragomir
55.8k33452
answered Nov 12 at 11:58
Titian Cernicova-Dragomir
55.8k33452
55.8k33452
function myFunction<T extends Function>(fn1: T, fn2: (...a: ArgTypes<T>) => string) :numbershould also work
– dotjpg3141
Nov 12 at 12:13
@dotjpg3141 I avoid usingFunctiondirectly .. but yeah that should also work :)
– Titian Cernicova-Dragomir
Nov 12 at 12:17
add a comment |
function myFunction<T extends Function>(fn1: T, fn2: (...a: ArgTypes<T>) => string) :numbershould also work
– dotjpg3141
Nov 12 at 12:13
@dotjpg3141 I avoid usingFunctiondirectly .. but yeah that should also work :)
– Titian Cernicova-Dragomir
Nov 12 at 12:17
function myFunction<T extends Function>(fn1: T, fn2: (...a: ArgTypes<T>) => string) :number should also work– dotjpg3141
Nov 12 at 12:13
function myFunction<T extends Function>(fn1: T, fn2: (...a: ArgTypes<T>) => string) :number should also work– dotjpg3141
Nov 12 at 12:13
@dotjpg3141 I avoid using
Function directly .. but yeah that should also work :)– Titian Cernicova-Dragomir
Nov 12 at 12:17
@dotjpg3141 I avoid using
Function directly .. but yeah that should also work :)– Titian Cernicova-Dragomir
Nov 12 at 12:17
add a comment |
Thanks for contributing an answer to Stack Overflow!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53261378%2ftwo-functions-with-same-arguments-but-different-return-type%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Any return type? Or two types specified by
myFunction?– Titian Cernicova-Dragomir
Nov 12 at 11:53
The return type of the first function can have any type. The return type of the second function is always string.
– dotjpg3141
Nov 12 at 11:55