Ability to select() tuple element as a whole

[MikelArnaiz]

Consider an input made of tuples + enums

enum Foo { ... }
enum Bar { ... }
type State = 
  | [Foo.A, Bar.A, {age: number}]
  | [Foo.A, Bar.B, {name: string, age: number}]

Note I'm using the last tuple element for the data, when patter matching I use a wildcard on it. Then I destructure the handler selections to access data

.with([Foo.A, Bar.A, __], ([_foo, _bar, data]) => {
  // do something with data
})
.with([Foo.A, Bar.B, __], ([_foo, _bar, data]) => {
  // do something with data
})

The only workaround with select I know is to list all data's properties

.with([Foo.A, Bar.A, { age: select('age')}], (data) => {
  // ...
})
.with([Foo.A, Bar.B, { name: select('name'), age: select('age') }], (data) => {
  // ...
})

Describe the solution you'd like

It would be great to select the wildcarted element

.with([Foo.A, Bar.A, __.select], (data) => {
  // ...
})
.with([Foo.A, Bar.B, __.select], (data) => {
  // ...
})

Describe alternatives you've considered
A workaround I'm using is to move the selection outside the pattern matching, but this doesn't act as a wildcard and only works if multiple cases have same data

const selectData = {
  name: select('name'),
  age: select('age')
}

...

.with([Foo.A, Bar.A, selectData], (data) => {
  // ...
})
.with([Foo.A, Bar.B, selectData], (data) => {
  // ...
})

[gvergnaud]

Hey, I believe you can already do this with the current version, only it's select() instead of __.select. Here is a sandbox demonstrating this:

https://codesandbox.io/s/broken-frog-wmx243?file=/src/index.ts

import { match, select } from "ts-pattern";
  
const f = (state: State) =>
  match(state)
    // data: { age: number }
    .with(["Foo.A", "Bar.A", select()], (data) => data)
    // data: { name: string, age: number }
    .with(["Foo.A", "Bar.B", select()], (data) => data)
    .exhaustive();