## Description
This PR makes struct fields private by default and introduces explicit
public struct fields:
```
pub struct Struct {
pub public_field: u8,
private_field: u8,
}
```
Private fields can be accessed only withing the module in which their
struct is declared.
Error messages are properly orchestrated so that no conflicting or
duplicated messages are emitted. Since the change is a breaking change,
relevant suggestion on how to fix the particular issue are given.
To avoid an abrupt breaking change, the errors are temporarily turned
into warnings. These warnings will become errors in the upcoming
versions of Sway. The demo section below demonstrate how the errors will
look like, and how a one warning equivalent looks now.
Standard library structs like `Vec` or `String`, are adapted where
needed by adding the `pub` keyword to the fields that are accessed
outside of the struct declaration module. Some of these fields should
very likely remain public, but some, like e.g., `RawBytes::ptr` or
`Vec::buf` should be private. Adjusting the standard library to properly
utilize private fields is out of scope of this PR and will be done
separately. I expect breaking changes in the STD once we start modeling
structs keeping encapsulation in mind.
In addition, the PR:
- migrates
[annotate_snippets](https://github.com/rust-lang/annotate-snippets-rs)
crate to its latest version (breaking changes)
- removes a redundant non-existing field error and orchestrates
non-existing field error with privacy errors
- replaces an invalid and misleading error when accessing fields on
storage elements that are not structs
Closes#4692.
## Known limitations
There is an issue in displaying multi-line code snippets, which is
independent of these changes, but wasn't apparent before. The issue is
visible in the demo section below, where the struct bodies are sometimes
not fully shown, and they should be. This issue is reported in #5499 and
will be solved in a separate PR.
## Demo (an excerpt 😄)
### Private struct field is inaccessible
### Struct cannot be instantiated
### Struct pattern must ignore inaccessible private fields
### Struct pattern has missing fields
### Errors temporarily turned into warnings
## Checklist
- [x] I have linked to any relevant issues.
- [x] I have commented my code, particularly in hard-to-understand
areas.
- [x] I have updated the documentation where relevant (API docs, the
reference, and the Sway book).
- [x] I have added tests that prove my fix is effective or that my
feature works.
- [x] I have added (or requested a maintainer to add) the necessary
`Breaking*` or `New Feature` labels where relevant.
- [x] I have done my best to ensure that my PR adheres to [the Fuel Labs
Code Review
Standards](https://github.com/FuelLabs/rfcs/blob/master/text/code-standards/external-contributors.md).
- [x] I have requested a review from the relevant team or maintainers.
## Summary
More information can be found in #2443 .
Notes for PR:
- The review is meant to take place using `mdbook` so check out the main
`README.md` to see how to run it in the browser
- This book is incomplete however there are a lot of pages so the idea
is to PR this into the repo soon so that subsequent reviews are smaller
- No CI added until the book is ready to replace the current book
- Ideally reviews are split between multiple people because there is a
lot of content
Closes#2443
## Pages Reviewed
@matt-user : Program Types -> Functions, Misc
Co-authored-by: Bikem <bengisuozaydin@gmail.com>
Co-authored-by: Matt <54373384+matt-user@users.noreply.github.com>
Co-authored-by: Cameron Carstens <54727135+bitzoic@users.noreply.github.com>
Co-authored-by: bing <bingcicle@proton.me>
Co-authored-by: Mitch Martin <111294749+mitch-fuel@users.noreply.github.com>
Co-authored-by: Mohammad Fawaz <mohammadfawaz89@gmail.com>
Co-authored-by: Luiz Felipe Bolsoni Gomes <8636507+LuizAsFight@users.noreply.github.com>
Co-authored-by: K1-R1 <77465250+K1-R1@users.noreply.github.com>
Co-authored-by: Alex Hansen <alex@alex-hansen.com>
