allow assignement without parentheses

[amtoine]

related to

• allow mut to take pipelines #9658
• Let with pipeline #9589

Note
this is mainly a note for myself not to forget about this 😌

Related problem

with #9658 and #9589, we can now not use the parentheses around pipelines to declare constants with let and varibles with mut 🥳

i think it would make sense to have the same feature for variable assignment.

Describe the solution you'd like

allow to write things like

mutable variables

mut a = ls | get name
$a = ls | where type == file | get name

and get the output of the ls | where type == file | get name inside the $a variable.

now we get the following parser error

Error: nu::parser::input_type_mismatch

  × Command does not support nothing input.
   ╭─[entry #2:1:1]
 1 │ $a = ls | where type == file | get name
   ·           ──┬──
   ·             ╰── command doesn't support nothing input
   ╰────

$env mutation

allow

$env.PATH = $env.PATH
    | split row (char esep)
    | prepend ($env.HOME | path join ".local" "bin")
    | prepend ($env.CARGO_HOME | path join "bin")
    | uniq

instead of

$env.PATH = (
    $env.PATH
        | split row (char esep)
        | prepend ($env.HOME | path join ".local" "bin")
        | prepend ($env.CARGO_HOME | path join "bin")
        | uniq
)

Describe alternatives you've considered

No response

Additional context and details

No response

[amtoine]

i also think allowing the same with const would make sense 👍

[agirardeau]

The docs at https://www.nushell.sh/book/configuration.html#path-configuration actually say to set $env.PATH as described in this FR, without parentheses:

$env.PATH = $env.PATH | split row (char esep)
  | append /usr/local/bin
  | append ($env.CARGO_HOME | path join bin)
  | append ($env.HOME | path join .local bin)
  | uniq # filter so the paths are unique

But adding this to my env.nu produces the same command doesn't support nothing input error as reported above. I'm on 0.93.0.

It seems like the docs need to be fixed.

[sholderbach]

Closing this in favor of the more general #12956