mddd_std/
parsers.rs

1use std::any::type_name;
2use std::marker::PhantomData;
3use std::str::FromStr;
4
5use mddd_traits::IParser;
6
7#[derive(Default)]
8pub struct BoolParser;
9
10#[derive(Default)]
11pub struct FromStrParser<T> {
12    phantom: PhantomData<T>,
13}
14
15#[derive(Default)]
16pub struct StringParser;
17
18#[derive(Default)]
19pub struct OptParser<T> {
20    phantom: PhantomData<T>,
21}
22
23impl IParser<bool> for BoolParser {
24    fn parse(src: &str) -> Result<bool, String> {
25        const VARIANTS: &[(&str, bool)] = &[
26            ("1", true),
27            ("y", true),
28            ("t", true),
29            ("0", false),
30            ("n", false),
31            ("f", false),
32        ];
33        let param = src.to_lowercase();
34        for (var, val) in VARIANTS.iter() {
35            if *var == param {
36                return Ok(*val);
37            }
38        }
39        Err("not a bool value".to_string())
40    }
41}
42
43impl<T: FromStr + 'static> IParser<T> for FromStrParser<T> {
44    fn parse(src: &str) -> Result<T, String> {
45        if let Ok(val) = T::from_str(src) {
46            return Ok(val);
47        }
48        let msg = format!("expected type {}", type_name::<T>());
49        Err(msg)
50    }
51}
52
53impl<T: 'static, P: IParser<T>> IParser<Option<T>> for OptParser<P> {
54    fn parse(src: &str) -> Result<Option<T>, String> {
55        Ok(Some(P::parse(src)?))
56    }
57}
58
59impl IParser<String> for StringParser {
60    fn parse(src: &str) -> Result<String, String> {
61        Ok(src.to_string())
62    }
63}
mddd_std/parsers.rs

mddd_std/
parsers.rs
