2022-02-18 11:03:55 +01:00

73 lines
2.0 KiB
Rust

//! Iterator implementation for `Capabilities`
use std::{borrow::Cow, collections::btree_map};
use serde_json::Value as JsonValue;
use super::Capabilities;
/// Reference to a capability.
#[derive(Debug)]
pub struct CapabilityRef<'a> {
name: &'a str,
value: Option<&'a JsonValue>,
caps: &'a Capabilities,
}
impl<'a> CapabilityRef<'a> {
/// Get name of the capability.
pub fn name(&self) -> &'a str {
self.name
}
/// Get value of the capability.
pub fn value(&self) -> Cow<'a, JsonValue> {
match self.value {
// unknown capability from btreemap iterator
Some(val) => Cow::Borrowed(val),
// O(1) lookup of known capability
None => self.caps.get(self.name).unwrap(),
}
}
}
/// An iterator over capabilities.
#[derive(Debug)]
pub struct CapabilitiesIter<'a> {
/// Reference to Capabilities
caps: &'a Capabilities,
/// Current position of the iterator
pos: usize,
/// Iterator for custom capabilities
custom_caps_iterator: btree_map::Iter<'a, String, JsonValue>,
}
impl<'a> CapabilitiesIter<'a> {
/// Creates a new CapabilitiesIter
pub(super) fn new(caps: &'a Capabilities) -> Self {
Self { caps, pos: 0, custom_caps_iterator: caps.custom_capabilities.iter() }
}
}
impl<'a> Iterator for CapabilitiesIter<'a> {
type Item = CapabilityRef<'a>;
fn next(&mut self) -> Option<Self::Item> {
match self.pos {
0 => {
self.pos += 1;
Some(CapabilityRef { name: "m.change_password", value: None, caps: self.caps })
}
1 => {
self.pos += 1;
Some(CapabilityRef { name: "m.room_versions", value: None, caps: self.caps })
}
_ => self.custom_caps_iterator.next().map(|(name, value)| CapabilityRef {
name,
value: Some(value),
caps: self.caps,
}),
}
}
}