feat: extend api with iterator for routes

[mbodmer]

Forward iterator access to the routes to allow collecting them as a client. This allows eg. collecting the routes to subscribe them when using the router in an MQTT usecase.

[fundon]

Thank you.

Maybe implement IntoIterator will be better.
You can checkout the result of CI.

[mbodmer]

Wow, thanks for your fast action. I've also forwarded into_iter() now

[fundon]

See https://github.com/viz-rs/path-tree/actions/runs/9402026412/job/25895157980?pr=41#step:4:241
You might just need to implement this trait https://doc.rust-lang.org/std/iter/trait.IntoIterator.html

168 + 
169 + impl IntoIterator for &PathTree<T> {
170 +     type IntoIter = core::slice::Iter<'_, (T, alloc::vec::Vec<parser::Piece>)>;
171 +     type Item = &(T, alloc::vec::Vec<parser::Piece>);
172 +     fn into_iter(self) -> Self::IntoIter {
173 +         self.iter()
174 +     }
175 + }

[fundon]

I'm interested in your MQTT case. Could you add a test case?

[mbodmer]

See https://github.com/viz-rs/path-tree/actions/runs/9402026412/job/25895157980?pr=41#step:4:241 You might just need to implement this trait https://doc.rust-lang.org/std/iter/trait.IntoIterator.html

168 + 
169 + impl IntoIterator for &PathTree<T> {
170 +     type IntoIter = core::slice::Iter<'_, (T, alloc::vec::Vec<parser::Piece>)>;
171 +     type Item = &(T, alloc::vec::Vec<parser::Piece>);
172 +     fn into_iter(self) -> Self::IntoIter {
173 +         self.iter()
174 +     }
175 + }

So instead of forwarding into_iter() from the vector you would prefer the implementation of the trait?

impl<T> IntoIterator for PathTree<T> {
    type Item = (T, Vec<Piece>);
    type IntoIter = IntoIter<(T, Vec<Piece>)>;

    fn into_iter(self) -> Self::IntoIter {
        self.routes.into_iter()
    }
}

[mbodmer]

I'm interested in your MQTT case. Could you add a test case?

It is not a 100% fit. The "problem" was that there is no root element in MQTT, as there is no leading "/" in a topic. I have used the workaround to prefix the route with "MQTT/". Would have preferred a direct usage, but this is ok.

Also not all matchers are used. The following code create a rumqttc SubscribeFilter from the Pieces:

// Newtype for rumqttc subscription filter to implement TryFrom locally
pub struct SubscribeFilter(rumqttc::v5::mqttbytes::v5::Filter);

impl Deref for SubscribeFilter {
    type Target = rumqttc::v5::mqttbytes::v5::Filter;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

/// Generates MQTT subscription from `TreePath` pieces
impl TryFrom<(&Vec<Piece>, &QoS)> for SubscribeFilter {
    type Error = Error;

    fn try_from(value: (&Vec<Piece>, &QoS)) -> Result<Self, Self::Error> {
        let mut bytes = Vec::new();
        let qos = *value.1;

        value.0.iter().try_for_each(|piece| match piece {
            Piece::String(s) => {
                bytes.extend_from_slice(s);
                Ok(())
            }
            Piece::Parameter(_, kind) => match kind {
                // single level wildcard, use like: "a/:name/b -> "a/+/b"
                Kind::Normal => {
                    bytes.extend_from_slice(b"+");
                    Ok(())
                }
                // multi level wildcard, use like: "a/:name*" -> "a/#"
                Kind::ZeroOrMore | Kind::ZeroOrMoreSegment => {
                    bytes.extend_from_slice(b"#");
                    Ok(())
                }
                // fail in other cases
                _ => Err(Error::ParseError(
                    "Unsupported route expression".to_string(),
                )),
            },
        })?;

        // construct topic from bytes and remove prefix if appliable
        let mut topic = from_utf8(&bytes).map_err(|e| Error::ParseError(e.to_string()))?;
        topic = topic.strip_prefix("MQTT/").unwrap_or(topic);

        Ok(SubscribeFilter(rumqttc::v5::mqttbytes::v5::Filter::new(
            topic, qos,
        )))
    }
}

Sure i can implement a testcase, do you have any pointers on what you have in mind?

[fundon]

So instead of forwarding into_iter() from the vector you would prefer the implementation of the trait?

Yes, like clippy said: https://rust-lang.github.io/rust-clippy/master/index.html#/iter_without_into_iter

[mbodmer]

could you please restart the build one more time?

[fundon]

It is not a 100% fit. The "problem" was that there is no root element in MQTT, as there is no leading "/" in a topic. I have used the workaround to prefix the route with "MQTT/". Would have preferred a direct usage, but this is ok.

Thank you for sharing.
Yes, a leading is required. It's fine.

[mbodmer]

Thank you for this library, it still was very useful

[fundon]

The CI's output:

help: consider implementing `IntoIterator` for `&PathTree<T>`
    |
168 + 
169 + impl IntoIterator for &PathTree<T> {
170 +     type IntoIter = core::slice::Iter<'_, (T, alloc::vec::Vec<parser::Piece>)>;
171 +     type Item = &(T, alloc::vec::Vec<parser::Piece>);
172 +     fn into_iter(self) -> Self::IntoIter {
173 +         self.iter()
174 +     }
175 + }

[mbodmer]

See https://github.com/viz-rs/path-tree/actions/runs/9402026412/job/25895157980?pr=41#step:4:241 You might just need to implement this trait https://doc.rust-lang.org/std/iter/trait.IntoIterator.html

168 + 
169 + impl IntoIterator for &PathTree<T> {
170 +     type IntoIter = core::slice::Iter<'_, (T, alloc::vec::Vec<parser::Piece>)>;
171 +     type Item = &(T, alloc::vec::Vec<parser::Piece>);
172 +     fn into_iter(self) -> Self::IntoIter {
173 +         self.iter()
174 +     }
175 + }

Hmm, i have implemented it, but clippy seems not to accept it: https://github.com/viz-rs/path-tree/pull/41/files#diff-b1a35a68f14e696205874893c07fd24fdb88882b47c23cc0e0c80a30c7d53759R267
The example provided by clippy from ci does not work, and my local clippy does not complain.
Do you have any idea?

Edit: I have now implemented IntoIterator for &PathTree, hope this works on CI

[fundon]

Thank you for your work.

[fundon]

Laned in v0.8.0.

[mbodmer]

Thanks for releasing, cool!