[Feature] Support referencing existing variable values directly without need for get_env_var

[fiftydinar]

Is your feature request related to a problem? Please describe.
Instead of need to do this:

import { get_env_var } from "std/env"

let home = get_env_var("HOME")
echo home

I simply want to do this:

echo ${HOME}

It is not convenient to use get_env_var every time you need to reference some existing variables.

Describe the solution you'd like
Maybe $var, ${var} or something similar can be used to reference those?

Describe alternatives you've considered
Besides keeping this as is (as worse alternative), I see no alternative.

Additional context
/

[b1ek]

why not do this?

echo get_env_var("HOME")

also imo it is a better solution to allow for $ to be defined as a function, instead of creating a builtin:

import { get_env_var as $ } from "std/env"

echo $("HOME")

[b1ek]

or maybe create a $ function in stdlib to allow for general bash syntax:

import { $ } from "std/util"

let a = "SMOL"
echo $("${nameof a},,") # smol

[fiftydinar]

why not do this?

echo get_env_var("HOME")

It's not suitable if I want to do this:

var="${HOME}/Downloads/"

which I often do in bash scripts.

also imo it is a better solution to allow for $ to be defined as a function, instead of creating a builtin:

import { get_env_var as $ } from "std/env"

echo $("HOME")

Doesn't work, errors out (Unclosed interpolation)

or maybe create a $ function in stdlib to allow for general bash syntax:

import { $ } from "std/util"

let a = "SMOL"
echo $("${nameof a},,") # smol

Doesn't work, errors out (Unclosed interpolation)

I guess I'll wait for 0.3.6 version & try again.