Files
pacdef_rust/crates/pacdef/src/grouping/package.rs
T

129 lines
3.7 KiB
Rust

use std::fmt::{Display, Write};
use std::hash::Hash;
/// A struct to represent a single package, consisting of a `name`, and
/// optionally a `repo`.
#[derive(Debug, Eq, PartialOrd, Ord, Clone)]
pub struct Package {
/// The name of the package
pub name: String,
/// Optionally, which repository the package belongs to
pub repo: Option<String>,
}
fn remove_comment_and_trim_whitespace(s: &str) -> &str {
s.split('#') // remove comment
.next()
.expect("line contains something")
.trim() // remove whitespace
}
impl From<String> for Package {
fn from(value: String) -> Self {
let trimmed = remove_comment_and_trim_whitespace(&value);
debug_assert!(!trimmed.is_empty(), "empty package names are not allowed");
let (name, repo) = Self::split_into_name_and_repo(trimmed);
Self { name, repo }
}
}
impl From<&str> for Package {
fn from(value: &str) -> Self {
Self::from(value.to_string())
}
}
impl Package {
/// From a string that contains a package name, optionally prefixed by a
/// repository, return the package name as well as the repository if it
/// exists.
///
/// # Panics
///
/// Panics if `string` is empty.
fn split_into_name_and_repo(string: &str) -> (String, Option<String>) {
if let Some((before, after)) = string.split_once('/') {
(after.to_string(), Some(before.to_string()))
} else {
(string.to_string(), None)
}
}
/// Try to parse a string (from a line in a group file) and return a package.
/// From the string, any possible comment is removed and whitespace is trimmed.
/// Returns `None` if there is nothing left after trimming.
pub fn try_from<S>(s: S) -> Option<Self>
where
S: AsRef<str>,
{
let trimmed = remove_comment_and_trim_whitespace(s.as_ref());
if trimmed.is_empty() {
return None;
}
let (name, repo) = Self::split_into_name_and_repo(trimmed);
Some(Self { name, repo })
}
}
impl PartialEq for Package {
fn eq(&self, other: &Self) -> bool {
let self_repo = self.repo.as_ref();
let other_repo = other.repo.as_ref();
// iff both packages have repos, they must be identical, otherwise we don't care
let repos_are_identical =
self_repo.map_or(true, |sr| other_repo.map_or(true, |or| sr == or));
let names_are_identical = self.name == other.name;
names_are_identical && repos_are_identical
}
}
impl Hash for Package {
fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
self.name.hash(state);
}
}
impl Display for Package {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
match &self.repo {
None => (),
Some(repo) => {
f.write_str(repo)?;
f.write_char('/')?;
}
}
f.write_str(&self.name)
}
}
#[cfg(test)]
mod tests {
use super::Package;
#[test]
fn split_into_name_and_repo() {
let x = "repo/name".to_string();
let (name, repo) = Package::split_into_name_and_repo(&x);
assert_eq!(name, "name");
assert_eq!(repo, Some("repo".to_string()));
let x = "something".to_string();
let (name, repo) = super::Package::split_into_name_and_repo(&x);
assert_eq!(name, "something");
assert_eq!(repo, None);
}
#[test]
fn from() {
let x = "myrepo/somepackage # ".to_string();
let p = Package::try_from(x).expect("this should be a valid package line");
assert_eq!(p.name, "somepackage");
assert_eq!(p.repo, Some("myrepo".to_string()));
}
}