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Support 'throw' expressions #18535
Description
Support proposal-throw-expressions.
That proposal is now stage-1, but worth to implements for convenience and this proposal not break backward-compatibilities.
Current
ts
const errorThrowExp = () => { throw new Error('Error!'); }
function errorThrowFn(maybeTrue) {
if (maybeTrue){
return ...;
} else {
throw new Error('Error!');
}
}js
const errorThrowExp = function() {throw new Error('Error!')}
function errorThrowFn(maybeTrue) {
if (maybeTrue){
return ...;
} else {
throw new Error('Error!');
}
}Proposal
ts
const errorThrower = () => throw new Error('Error!');
function errorThrowFn(maybeTrue: boolean) {
return maybeTrue? ...: throw new Error('Error!');
}js
const errorThrower = function() { throw new Error('Error!'); }
function errorThrowFn(maybeTrue: boolean) {
return maybeTrue? ...: (function() { throw new Error('Error!') })();
}
Activity
kitsonk commentedon Sep 17, 2017
Just to note, Ron Buckton (@rbuckton) is closely aligned to the TypeScript team. I highly suspect this proposal would be implemented when everyone is comfortable it is in a stable enough position.
brn commentedon Sep 17, 2017
Kitson Kelly (@kitsonk) That make sense.
So is this proposal premature?
[-]Support throw-expressions[/-][+]Support 'throw' Expressions[/+][-]Support 'throw' Expressions[/-][+]Support 'throw' expressions[/+]DanielRosenwasser commentedon Sep 17, 2017
Nope, it's fine to track it here. Like Kitson Kelly (@kitsonk) said, Ron Buckton (@rbuckton) is championing it and is part of our team, but we will need it to reach a later stage before adopting it in TypeScript.
For what it's worth, I'd be willing to bet he has a branch with an implementation of
throw-expressions. 😄rbuckton commentedon Sep 18, 2017
https://github.com/Microsoft/TypeScript/tree/throwOperator?files=1
Currently it does not yet support unreachability checks at the expression level. Also, I am waiting for the next TC39 meeting to see if the proposal moves to Stage 2.
brn commentedon Sep 18, 2017
Daniel Rosenwasser (@DanielRosenwasser) Ron Buckton (@rbuckton)
I got it.
Thank you for the detailed explanation!
Yogu commentedon May 11, 2018
The proposal is now in stage 2 - would be cool if this gets implemented in TypeScript.
rbuckton commentedon May 12, 2018
TypeScript's current stance is that we will not adopt a proposed JavaScript feature until it has reached Stage 3. Currently, Stage 3 for
throwexpressions is blocked from advancement due to overlap with thedoexpressions proposal.Yogu commentedon May 12, 2018
Ah, I see. Thanks, Ron Buckton (@rbuckton)!
lufzle commentedon Jun 24, 2019
This is now in stage 3 :)
rbuckton commentedon Jun 24, 2019
No, this has not yet advanced to Stage 3.
RyanCavanaugh commentedon Mar 15, 2024
Closing since there's nothing for us to do but wait for TC39