simple_toml_parser/
lib.rs

1#[derive(Debug, Clone, PartialEq, Eq)]
2pub enum TOMLKey<'a> {
3    Slice(&'a str),
4    Index(usize),
5}
6
7#[derive(Debug, PartialEq, Eq)]
8pub enum RootTOMLValue<'a> {
9    String(&'a str),
10    Number(&'a str),
11    Boolean(bool),
12    Null,
13}
14
15#[derive(Debug)]
16pub enum TOMLParseErrorReason {
17    ExpectedColon,
18    ExpectedEndOfValue,
19    ExpectedBracket,
20    ExpectedTrueFalseNull,
21    ExpectedValue,
22}
23
24#[derive(Debug)]
25pub struct TOMLParseError {
26    pub at: usize,
27    pub reason: TOMLParseErrorReason,
28}
29
30impl std::error::Error for TOMLParseError {}
31
32impl std::fmt::Display for TOMLParseError {
33    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
34        f.write_fmt(format_args!(
35            "TOMLParseError: {:?} at {:?}",
36            self.reason, self.at
37        ))
38    }
39}
40
41/// If you want to return early (not parse the whole input) use [`parse_with_exit_signal`]
42///
43/// # Errors
44/// Returns an error if it tries to parse invalid TOML input
45pub fn parse<'a>(
46    on: &'a str,
47    mut cb: impl for<'b> FnMut(&'b [TOMLKey<'a>], RootTOMLValue<'a>),
48) -> Result<(), TOMLParseError> {
49    parse_with_exit_signal(on, |k, v| {
50        cb(k, v);
51        false
52    })
53}
54
55/// # Errors
56/// Returns an error if it tries to parse invalid TOML input
57/// # Panics
58/// On unimplemented items
59#[allow(clippy::too_many_lines)]
60pub fn parse_with_exit_signal<'a>(
61    on: &'a str,
62    mut cb: impl for<'b> FnMut(&'b [TOMLKey<'a>], RootTOMLValue<'a>) -> bool,
63) -> Result<(), TOMLParseError> {
64    let mut key_chain = Vec::new();
65    let lines = on.lines();
66
67    for line in lines {
68        if line.starts_with("[[") {
69            let _ = key_chain.drain(..);
70            assert!(line.ends_with("]]"), "TODO error");
71
72            let idx = if let Some(TOMLKey::Index(idx)) = key_chain.last() {
73                idx + 1
74            } else {
75                0
76            };
77            // TODO strings parsing here
78            for part in line[1..(line.len() - "]]".len())].split('.') {
79                key_chain.push(TOMLKey::Slice(part));
80            }
81            key_chain.push(TOMLKey::Index(idx));
82        } else if line.starts_with('[') {
83            let _ = key_chain.drain(..);
84            assert!(line.ends_with(']'), "TODO error");
85            // TODO strings parsing here
86            for part in line[1..(line.len() - "]".len())].split('.') {
87                key_chain.push(TOMLKey::Slice(part));
88            }
89        } else {
90            if line.starts_with('#') || line.is_empty() {
91                continue;
92            }
93            if let Some((key, value)) = line.split_once('=') {
94                let length = key_chain.len();
95                for part in key.trim().split('.') {
96                    key_chain.push(TOMLKey::Slice(part));
97                }
98
99                let value = value.trim();
100                let value = if let "true" | "false" = value {
101                    RootTOMLValue::Boolean(value == "true")
102                } else if value.starts_with(['"', '\'']) {
103                    assert!(
104                        value.ends_with(value.chars().next().unwrap()),
105                        "TODO unclosed string"
106                    );
107                    RootTOMLValue::String(&value[1..(value.len() - 1)])
108                } else if value.starts_with(char::is_numeric) {
109                    RootTOMLValue::Number(value)
110                } else {
111                    eprintln!("here {value}");
112                    continue;
113                };
114
115                let _result = cb(&key_chain, value);
116
117                let _ = key_chain.drain(length..);
118            } else {
119                panic!("bad key")
120            }
121        }
122    }
123
124    Ok(())
125}
simple_toml_parser/lib.rs

simple_toml_parser/
lib.rs
