bitsy_lang/
context.rs

1/// A [`Context`] is an associative list which assigns each element with type information.
2#[derive(Clone, Debug)]
3pub struct Context<K, T>(Vec<(K, T)>);
4
5impl<K: Eq + Clone, T: Clone> Context<K, T> {
6    pub fn empty() -> Context<K, T> {
7        Context(vec![])
8    }
9
10    pub fn from(ctx: Vec<(K, T)>) -> Context<K, T> {
11        Context(ctx)
12    }
13
14    pub fn lookup(&self, v: &K) -> Option<T> {
15        for (v0, t) in &self.0 {
16            if v0 == v {
17                return Some(t.clone());
18            }
19        }
20        None
21    }
22
23    pub fn extend(&self, v: K, t: T) -> Context<K, T> {
24        let mut result = self.clone();
25        result.0.push((v, t));
26        result
27    }
28
29    pub fn extend_from(&self, another: &Context<K, T>) -> Context<K, T> {
30        let mut result = self.clone();
31        for (v, t) in another.0.iter() {
32            result.0.push((v.clone(), t.clone()));
33        }
34        result
35    }
36
37    pub fn into_inner(self) -> Vec<(K, T)> {
38        self.0
39    }
40}
41
42impl<K, T> std::ops::Deref for Context<K, T> {
43    type Target = Vec<(K, T)>;
44
45    fn deref(&self) -> &Self::Target {
46        &self.0
47    }
48}
49
50impl<K: std::fmt::Display, T: std::fmt::Display> std::fmt::Display for Context<K, T> {
51    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
52        write!(f, "[")?;
53        for (i, (name, v)) in self.0.iter().enumerate() {
54            write!(f, "{name} : {v}")?;
55            if i + 1 < self.0.len() {
56                write!(f, ", ")?;
57            }
58        }
59        write!(f, "]")?;
60        Ok(())
61    }
62}
bitsy_lang/context.rs

bitsy_lang/
context.rs
