Extract const code action

[lpil]

An action that extracts a highlighted value and replaces it with a const

pub fn main() {
  list.map([1, 2, 3], run)
  #        ^^^^^^^^^
}

const value = [1, 2, 3]

pub fn main() {
  list.map(value, run)
}

[matiascr]

I'm taking a look at this. I'm guessing this should also perform these kinds of conversions?

Before:

pub fn main() {
  let l = ["A", "B", "C"]
  list.map(l, run)
}

After extracting whole composite type (as long as the contents are all literals):

const l = ["A", "B", "C"]

pub fn main() {
  list.map(l, run)
}

Or after extracting by individual literals:

const string = "A"

pub fn main() {
  let l = [string, "B", "C"]
  list.map(l, run)
}

[lpil]

Yeah!!

[matiascr]

WIP @ #4228
Currently extracts literals (Int, Float, String) in

• Literals in right hand side of assignments
• Literals inside lists and tuples
• Lists and tuples of literals
• Literal function arguments

Next steps

• Extracting whole variable declaration as constant declaration
• Extacting individual type variants

[lpil]

If you'd like to PR just a subset of expressions to start that would be good by me!

[matiascr]

Sounds great. I've cleaned it up and put it here #4228

[GearsDatapacks]

I believe this can be closed now, as the relevant PR has been merged