vfmt: automatically add imports for vlib modules

[islonely]

Describe the feature

vfmt should get the mod names from the vlib directory and add import <mod_name> to the top of your file if it's missing.

Use Case

source:

fn main() {
	println(time.minute)
}

after running v fmt -w <file>:

module main

import time

fn main() {
	println(time.minute)
}

Proposed Solution

No response

Other Information

No response

Acknowledgements

• I may be able to implement this feature request
• This feature might incur a breaking change

Version used

V 0.4.9 495adc9

Environment details (OS name and version, etc.)

V 0.4.9 4225a34.495adc9

V full version	V 0.4.9 4225a34.495adc9
OS	macos, macOS, 15.1.1, 24B91
Processor	8 cpus, 64bit, little endian, Apple M3
Memory	0.11GB/16GB
V executable	/Users/adamoates/v/v
V last modified time	2025-01-04 20:09:49
V home dir	OK, value: /Users/adamoates/v
VMODULES	OK, value: /Users/adamoates/.vmodules
VTMP	OK, value: /tmp/v_501
Current working dir	OK, value: /Users/adamoates/Documents/shattlebip
Git version	git version 2.39.5 (Apple Git-154)
V git status	weekly.2024.53-29-g495adc9c (8 commit(s) behind V master)
.git/config present	true
cc version	Apple clang version 16.0.0 (clang-1600.0.26.4)
gcc version	Apple clang version 16.0.0 (clang-1600.0.26.4)
clang version	Apple clang version 16.0.0 (clang-1600.0.26.4)
tcc version	tcc version 0.9.28rc 2024-02-05 HEAD@105d70f7 (AArch64 Darwin)
tcc git status	thirdparty-macos-arm64 713692d4
emcc version	N/A
glibc version	N/A

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[jorgeluismireles]

Afaik vfmt is not even able to sort import rows alphabetically. Is not too much for vfmt to append "missing" rows?

[JalonSolov]

It doesn't sort now... but it could. It could also add missing imports... maybe?

[spytheman]

It should not sort stuff, especially imports.

[JalonSolov]

It would be fine if it sorted them, as long as there was no order-dependence on the imports.

[jorgeluismireles]

It should not sort stuff, especially imports.

When using fn init() or/and fn cleanup() the sort change the calls:
File two/two.v:

module two

fn init() {
	println('init-two')
}

fn cleanup() {
	println('cleanup-two')
}

File three/three.v:

module three

fn init() {
	println('init-three')
}

fn cleanup() {
	println('cleanup-three')
}

This program:

module main

import two as _
import three as _

fn main() {

}

produces:

init-two
init-three
cleanup-three
cleanup-two

A would sort of the previous program:

module main

import three as _
import two as _

fn main() {

}

produces something different:

init-three
init-two
cleanup-two
cleanup-three

[JalonSolov]

... and that shows an instance of the order dependence I was talking about.

It wouldn't hurt a thing if those init and cleanup routines didn't affect each other, but they could, so sorting will change how they work, possibly causing crashes, etc.