Extract Key/Value object from tuple type

[fringe stone]

I have a tuple type MyTuple and want to generate an object from it like so:

type MyTuple = [{ name: 'abc'; value: string }, { name: 'cde'; value: number }];

/*
type ObjectFromNameToValues = {
    abc: string;
    cde: number;
}
*/
type ObjectFromNameToValues = {
  [Name in MyTuple[number]['name']]: Extract<MyTuple[number], { name: Name }>['value'];
};

The comment shows the final inferred type of ObjectFromNameToValues

Now, this works, but it’s incredibly wasteful to fetch the subtypes of my tuple with [number] and then infer the value type with Extract. Is there any way to refer to the index of the tuple to use it? Something like

type ObjectFromNameToValues = {
  [Name in MyTuple[number as Idx]['name']]: MyTuple[Idx]['value'];
};

[bright saddle]

does this work?

type ObjectFromNameToValues = {
  [Name in MyTuple[number]["name"]]: Extract<MyTuple[number], { name: Name }>["value"];
};

[fringe stone]

Yes, that’s from the first code snippet

[narrow lagoon]

Use as renaming.

type MyTuple = [{ name: 'abc'; value: string }, { name: 'cde'; value: number }]

type Result = {
    [T in MyTuple[number] as T['name']]: T['value']
}

!ts Result

[split jasper]

type Result = {
    abc: string;
    cde: number;
} /* 3:6 */```

[fringe stone]

That works! amazing, than you