rosrust/api/naming/
mapper.rs

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1use super::path::{Buffer, Path, Slice};
2use std::collections::HashMap;
3
4pub struct Mapper {
5    children: HashMap<String, Mapper>,
6    value: Option<Buffer>,
7}
8
9impl Mapper {
10    pub fn new() -> Mapper {
11        Mapper {
12            children: HashMap::new(),
13            value: None,
14        }
15    }
16
17    pub fn add(&mut self, keys: &[String], value: Buffer) {
18        match keys.split_first() {
19            None => {
20                self.value = Some(value);
21            }
22            Some((key, child_keys)) => {
23                self.children
24                    .entry(key.clone())
25                    .or_insert_with(Mapper::new)
26                    .add(child_keys, value);
27            }
28        }
29    }
30
31    pub fn translate(&self, keys: &[String]) -> Option<Slice> {
32        match keys.split_first() {
33            None => self.value.as_ref().map(Path::slice),
34            Some((key, child_keys)) => self.children.get(key).and_then(|v| v.translate(child_keys)),
35        }
36    }
37}
38
39#[cfg(test)]
40mod tests {
41    use super::super::path::{Buffer, Path};
42    use super::*;
43
44    static FAILED_TO_MAP: &str = "Failed to map";
45
46    #[test]
47    fn matches_existing_paths() {
48        let mut mapper = Mapper::new();
49        let src1 = "/foo/bar".parse::<Buffer>().expect(FAILED_TO_MAP);
50        let dst = "/a/b/c".parse::<Buffer>().expect(FAILED_TO_MAP);
51        mapper.add(src1.get(), dst);
52        let src2 = "/foo/ter".parse::<Buffer>().expect(FAILED_TO_MAP);
53        let dst = "/d/e/f".parse::<Buffer>().expect(FAILED_TO_MAP);
54        mapper.add(src2.get(), dst);
55        assert_eq!(
56            "/a/b/c",
57            format!("{}", mapper.translate(src1.get()).expect(FAILED_TO_MAP))
58        );
59        assert_eq!(
60            "/d/e/f",
61            format!("{}", mapper.translate(src2.get()).expect(FAILED_TO_MAP))
62        );
63    }
64
65    #[test]
66    fn allows_root_path() {
67        let mut mapper = Mapper::new();
68        let src1 = "/".parse::<Buffer>().expect(FAILED_TO_MAP);
69        let dst = "/a/b/c".parse::<Buffer>().expect(FAILED_TO_MAP);
70        mapper.add(src1.get(), dst);
71        let src2 = "/foo/ter".parse::<Buffer>().expect(FAILED_TO_MAP);
72        let dst = "/".parse::<Buffer>().expect(FAILED_TO_MAP);
73        mapper.add(src2.get(), dst);
74        assert_eq!(
75            "/a/b/c",
76            format!("{}", mapper.translate(src1.get()).expect(FAILED_TO_MAP))
77        );
78        assert_eq!(
79            "",
80            format!("{}", mapper.translate(src2.get()).expect(FAILED_TO_MAP))
81        );
82    }
83
84    #[test]
85    fn fails_missing_paths() {
86        let mut mapper = Mapper::new();
87        let src1 = "/foo/bar".parse::<Buffer>().expect(FAILED_TO_MAP);
88        let dst = "/a/b/c".parse::<Buffer>().expect(FAILED_TO_MAP);
89        mapper.add(src1.get(), dst);
90        let src2 = "/foo/ter".parse::<Buffer>().expect(FAILED_TO_MAP);
91        let dst = "/d/e/f".parse::<Buffer>().expect(FAILED_TO_MAP);
92        mapper.add(src2.get(), dst);
93        let src3 = "/foo/bla".parse::<Buffer>().expect(FAILED_TO_MAP);
94        assert!(mapper.translate(src3.get()).is_none());
95    }
96
97    #[test]
98    fn allows_to_redefine() {
99        let mut mapper = Mapper::new();
100        let src = "/foo/bar".parse::<Buffer>().expect(FAILED_TO_MAP);
101        let dst1 = "/a/b/c".parse::<Buffer>().expect(FAILED_TO_MAP);
102        mapper.add(src.get(), dst1);
103        assert_eq!(
104            "/a/b/c",
105            format!("{}", mapper.translate(src.get()).expect(FAILED_TO_MAP))
106        );
107        let dst2 = "/d/e/f".parse::<Buffer>().expect(FAILED_TO_MAP);
108        mapper.add(src.get(), dst2);
109        assert_eq!(
110            "/d/e/f",
111            format!("{}", mapper.translate(src.get()).expect(FAILED_TO_MAP))
112        );
113    }
114}
rosrust/api/naming/mapper.rs

rosrust/api/naming/
mapper.rs
