Semantic versions

use semver.qweruse semver_compare, semver_matches from semver      // Quillo 0.6: only these

semver = "1"

// Which release a client should update to.////   quillo run semver.qwe      then open http://localhost:8080/update?have=1.2.0use "semver.qwer"let releases = ["1.2.0", "1.2.5", "1.3.0", "2.0.0-rc.1", "2.0.0", "2.1.0"]route GET /update ? { have: str } = {    same_major: semver_newest(releases, `^${have}`)?,    newest: semver_newest(releases, "*")?,    next_minor: semver_bump(have, "minor")?,    behind: semver_compare(have, "2.1.0")? < 0,}

//! Semantic versions compared and matched against ranges as Cargo and npm write them (`^1.2`, `>=2, <3`).//! version: 1.0.0//!//! [dependencies]//! semver = "1"use semver::{Version, VersionReq};fn v(s: &str) -> Result<Version, String> {    Version::parse(s.trim().trim_start_matches('v')).map_err(|e| format!("{}: {}", s, e))}/// -1, 0 or 1 as `a` comes before, is, or comes after `b` (`1.10.0` after `1.9.0`; `2.0.0-rc.1` before `2.0.0`).pub fn semver_compare(a: &str, b: &str) -> Result<i64, String> {    Ok(match v(a)?.cmp(&v(b)?) { std::cmp::Ordering::Less => -1, std::cmp::Ordering::Equal => 0, std::cmp::Ordering::Greater => 1 })}/// Whether `version` is in the range `req`: `semver_matches("1.4.2", "^1.2")`.pub fn semver_matches(version: &str, req: &str) -> Result<bool, String> {    Ok(VersionReq::parse(req).map_err(|e| e.to_string())?.matches(&v(version)?))}/// The newest of `versions` in the range `req`, or null; versions that do not parse are skipped.pub fn semver_newest(versions: Vec<String>, req: &str) -> Result<Option<String>, String> {    let r = VersionReq::parse(req).map_err(|e| e.to_string())?;    Ok(versions.iter().filter_map(|s| v(s).ok().map(|p| (p, s))).filter(|(p, _)| r.matches(p)).max_by(|a, b| a.0.cmp(&b.0)).map(|(_, s)| s.clone()))}/// The version after `version`, by `part`: "major", "minor" or "patch".pub fn semver_bump(version: &str, part: &str) -> Result<String, String> {    let mut x = v(version)?;    x.pre = semver::Prerelease::EMPTY;    x.build = semver::BuildMetadata::EMPTY;    match part {        "major" => { x.major += 1; x.minor = 0; x.patch = 0; }        "minor" => { x.minor += 1; x.patch = 0; }        "patch" => x.patch += 1,        _ => return Err(format!("the part is major, minor or patch, not `{}`", part)),    }    Ok(x.to_string())}