regex_set_map/
lib.rs

1use config::{any_err, get_or_create_sub_module};
2use mlua::prelude::LuaUserData;
3use mlua::{FromLua, Lua, MetaMethod, UserDataMethods};
4use mod_memoize::CacheValue;
5use regex::{RegexSet, RegexSetBuilder};
6use serde::{Deserialize, Serialize};
7use std::collections::HashMap;
8
9#[derive(Clone, Serialize, Deserialize)]
10#[serde(try_from = "RegexSetMapBuilder<V>", into = "RegexSetMapBuilder<V>")]
11pub struct RegexSetMap<V: Clone> {
12    set: RegexSet,
13    pattern_to_value: Vec<V>,
14}
15
16impl<V: Clone> RegexSetMap<V> {
17    pub fn lookup(&self, subject: &str) -> Option<&V> {
18        self.set
19            .matches(subject)
20            .into_iter()
21            .next()
22            .and_then(|idx| self.pattern_to_value.get(idx))
23    }
24}
25
26impl<V: Clone> From<RegexSetMap<V>> for RegexSetMapBuilder<V> {
27    fn from(map: RegexSetMap<V>) -> Self {
28        let patterns = map.set.patterns().to_vec();
29        RegexSetMapBuilder {
30            patterns,
31            pattern_to_value: map.pattern_to_value,
32        }
33    }
34}
35
36impl<V: Clone> TryFrom<RegexSetMapBuilder<V>> for RegexSetMap<V> {
37    type Error = String;
38
39    fn try_from(builder: RegexSetMapBuilder<V>) -> Result<RegexSetMap<V>, String> {
40        builder.build()
41    }
42}
43
44#[derive(Serialize, Deserialize)]
45pub struct RegexSetMapBuilder<V: Clone> {
46    patterns: Vec<String>,
47    pattern_to_value: Vec<V>,
48}
49
50impl<V: Clone> Default for RegexSetMapBuilder<V> {
51    fn default() -> Self {
52        Self::new()
53    }
54}
55
56impl<V: Clone> RegexSetMapBuilder<V> {
57    pub fn new() -> Self {
58        Self {
59            patterns: vec![],
60            pattern_to_value: vec![],
61        }
62    }
63
64    pub fn add_rule<S: Into<String>>(&mut self, rule: S, value: V) {
65        self.patterns.push(rule.into());
66        self.pattern_to_value.push(value);
67    }
68
69    pub fn build(mut self) -> Result<RegexSetMap<V>, String> {
70        self.patterns.shrink_to_fit();
71        self.pattern_to_value.shrink_to_fit();
72
73        let set = RegexSetBuilder::new(self.patterns)
74            .build()
75            .map_err(|err| format!("compiling rules: {err:#}"))?;
76        Ok(RegexSetMap {
77            set,
78            pattern_to_value: self.pattern_to_value,
79        })
80    }
81}
82
83impl LuaUserData for RegexSetMap<CacheValue> {
84    fn add_methods<M: UserDataMethods<Self>>(methods: &mut M) {
85        mod_memoize::Memoized::impl_memoize(methods);
86        methods.add_meta_method(MetaMethod::Index, |lua, this, key: String| {
87            if let Some(value) = this.lookup(&key) {
88                let value = value.as_lua(lua)?;
89                Ok(Some(value))
90            } else {
91                Ok(None)
92            }
93        });
94    }
95}
96
97pub fn register(lua: &Lua) -> anyhow::Result<()> {
98    let module = get_or_create_sub_module(lua, "regex_set_map")?;
99
100    module.set(
101        "new",
102        lua.create_function(|lua, value: Option<HashMap<String, mlua::Value>>| {
103            let mut builder: RegexSetMapBuilder<CacheValue> = RegexSetMapBuilder::new();
104
105            if let Some(value) = value {
106                for (k, v) in value {
107                    let v = CacheValue::from_lua(v, lua)?;
108                    builder.add_rule(&k, v);
109                }
110            }
111
112            builder.build().map_err(any_err)
113        })?,
114    )?;
115
116    Ok(())
117}
118
119#[cfg(test)]
120mod test {
121    use super::*;
122
123    #[test]
124    fn test_basic_mapping() {
125        let mut builder = RegexSetMapBuilder::new();
126        builder.add_rule(
127            "4\\.2\\.2 The email account that you tried to reach is over quota\\.",
128            500,
129        );
130        builder.add_rule("4\\.2\\.1 <.+>: Recipient address rejected: this mailbox is inactive and has been disabled", 501);
131        builder.add_rule("4\\.1\\.1 <.*> 4.2.2 mailbox full\\.", 502);
132        let mapper = builder.build().unwrap();
133
134        let corpus = &[
135            ("400 4.2.2 The email account that you tried to reach is over quota", None),
136            ("400 4.2.2 The email account that you tried to reach is over quota.", Some(500)),
137            ("400 4.2.1 <foo>: Recipient address rejected: this mailbox is inactive and has been disabled", Some(501)),
138            ("400 4.1.1 <bar> 4.2.2 mailbox full.", Some(502)),
139        ];
140
141        for &(input, output) in corpus {
142            assert_eq!(
143                mapper.lookup(input),
144                output.as_ref(),
145                "expected {input} -> {output:?}"
146            );
147        }
148    }
149}
regex_set_map/lib.rs

regex_set_map/
lib.rs
