Add basename, extension, filename, parent

[pithonsmear]

Problem: Missing string methods

Solution: Add some of them

Changes introduced by this pull request:

• $basename: Print NAME without leading directories
• $extension: Print extension of NAME
• $filename: Print NAME without extension (if there is one)
• $parent: Print parent of NAME (if there is one)

[mmstick]

The Rust standard library ships abstractions for this purpose, to handle paths in a cross-platform manner.

use std::path::Path;

fn main() {
    let path = "/grand_parent/parent/filename.ext";
    let basename = Path::new(path).file_name()
        .and_then(|os_str| os_str.to_str())
        .unwrap_or(path);
    let extension = Path::new(path).extension()
        .and_then(|os_str| os_str.to_str())
        .unwrap_or(path);
    let file_stem = Path::new(path).file_stem()
        .and_then(|os_str| os_str.to_str())
        .unwrap_or(path);
    let parent = Path::new(path).parent()
        .and_then(|os_str| os_str.to_str())
        .unwrap_or(path);
    println!("basename: {}\nextension: {}\nfile_stem: {}\nparent: {}", basename, extension, file_stem, parent);
}

https://play.rust-lang.org/?gist=1e6605eb6806c41cefaf1949aff214aa&version=stable

You might want to use those instead.

[pithonsmear]

Absolutely. Lemme do this one over.

[mmstick]

No need to close the PR. You can perform a git push origin patch-1 to push any fixes to this branch.

[pithonsmear]

Ok, looks like I managed to update the branch with the new methods, but there are some other changes that I don't know why happened.

[mmstick]

Thanks for the work!

[pithonsmear]

No, thank you. In the end I didn't really do anything of value to the project, since you gave me the solution, but I did learn!

[mmstick]

@pithonsmear I wouldn't say that what you did wasn't valuable to the project. Gaining experience with Rust, and familiarity with the Ion codebase, gives value to the project in itself -- especially if you continue to submit PRs. Plus, you did the work in integrating the logic needed to get this pushed through, and that's what matters.