whichtime_sys/parsers/de/
casual_time.rs

1//! German casual time parser
2//!
3//! Handles standalone German time expressions like:
4//! - "mittag" (noon), "mitternacht" (midnight)
5//! - "diesen Morgen" (this morning)
6
7use crate::components::Component;
8use crate::context::ParsingContext;
9use crate::error::Result;
10use crate::parsers::Parser;
11use crate::results::ParsedResult;
12use crate::types::Meridiem;
13use chrono::{Datelike, Duration, Timelike};
14use fancy_regex::Regex;
15use std::sync::LazyLock;
16
17static PATTERN: LazyLock<Regex> = LazyLock::new(|| {
18    Regex::new(
19        r"(?i)(?:(diese[rnms]?)\s*)?(morgen|vormittag|mittags?|nachmittag|abend|nacht|mitternacht)(?=\W|$)"
20    ).unwrap()
21});
22
23const _MODIFIER_GROUP: usize = 1;
24const TIME_GROUP: usize = 2;
25
26/// German casual time parser
27pub struct DECasualTimeParser;
28
29impl DECasualTimeParser {
30    pub fn new() -> Self {
31        Self
32    }
33}
34
35impl Parser for DECasualTimeParser {
36    fn name(&self) -> &'static str {
37        "DECasualTimeParser"
38    }
39
40    fn should_apply(&self, _context: &ParsingContext) -> bool {
41        true
42    }
43
44    fn parse(&self, context: &ParsingContext) -> Result<Vec<ParsedResult>> {
45        let mut results = Vec::new();
46        let ref_date = context.reference.instant;
47
48        let mut start = 0;
49        while start < context.text.len() {
50            let search_text = &context.text[start..];
51            let captures = match PATTERN.captures(search_text) {
52                Ok(Some(caps)) => caps,
53                Ok(None) => break,
54                Err(_) => break,
55            };
56
57            let full_match = match captures.get(0) {
58                Some(m) => m,
59                None => break,
60            };
61
62            let match_start = start + full_match.start();
63            let match_end = start + full_match.end();
64
65            let time_keyword = captures
66                .get(TIME_GROUP)
67                .map(|m| m.as_str().to_lowercase())
68                .unwrap_or_default();
69
70            let mut components = context.create_components();
71
72            // Set today's date by default
73            let mut target_date = ref_date;
74
75            match time_keyword.as_str() {
76                "morgen" => {
77                    components.imply(Component::Hour, 6);
78                    components.imply(Component::Minute, 0);
79                    components.assign(Component::Meridiem, Meridiem::AM as i32);
80                }
81                "vormittag" => {
82                    components.imply(Component::Hour, 9);
83                    components.imply(Component::Minute, 0);
84                    components.assign(Component::Meridiem, Meridiem::AM as i32);
85                }
86                "mittag" | "mittags" => {
87                    components.imply(Component::Hour, 12);
88                    components.imply(Component::Minute, 0);
89                    components.assign(Component::Meridiem, Meridiem::PM as i32);
90                }
91                "nachmittag" => {
92                    components.imply(Component::Hour, 15);
93                    components.imply(Component::Minute, 0);
94                    components.assign(Component::Meridiem, Meridiem::PM as i32);
95                }
96                "abend" => {
97                    components.imply(Component::Hour, 18);
98                    components.imply(Component::Minute, 0);
99                    components.assign(Component::Meridiem, Meridiem::PM as i32);
100                }
101                "nacht" => {
102                    components.imply(Component::Hour, 22);
103                    components.imply(Component::Minute, 0);
104                    components.assign(Component::Meridiem, Meridiem::PM as i32);
105                }
106                "mitternacht" => {
107                    // Midnight: if reference time is after noon, advance to next day
108                    if ref_date.hour() >= 6 {
109                        target_date = ref_date + Duration::days(1);
110                    }
111                    components.imply(Component::Hour, 0);
112                    components.imply(Component::Minute, 0);
113                    components.imply(Component::Second, 0);
114                }
115                _ => {
116                    start = match_end;
117                    continue;
118                }
119            }
120
121            components.assign(Component::Year, target_date.year());
122            components.assign(Component::Month, target_date.month() as i32);
123            components.assign(Component::Day, target_date.day() as i32);
124
125            results.push(context.create_result(match_start, match_end, components, None));
126
127            start = match_end;
128        }
129
130        Ok(results)
131    }
132}
133
134impl Default for DECasualTimeParser {
135    fn default() -> Self {
136        Self::new()
137    }
138}
whichtime_sys/parsers/de/casual_time.rs

whichtime_sys/parsers/de/
casual_time.rs
