krafna 0.5.6

Krafna is a terminal-based alternative to Obsidian's Dataview plugin, allowing you to query your Markdown files using standard SQL syntax.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154

use std::fmt::{Debug, Display};

#[derive(Debug)]
pub struct PeekableDeque<T> {
    deque: Vec<T>,
    index: usize,
}

impl<T: Display> PeekableDeque<T> {
    // Method to peek at the next item without removing it
    pub fn peek(&self) -> Option<&T> {
        self.deque.get(self.index)
    }

    pub fn back(&mut self, n: usize) {
        self.index = self.index.saturating_sub(n)
    }

    pub fn end(&self) -> bool {
        self.index >= self.deque.len()
    }
}

impl<T: Display> Display for PeekableDeque<T> {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        let formatted_str: String = self
            .deque
            .iter()
            .enumerate()
            .map(|(i, c)| {
                if i == self.index {
                    format!("[{}]", c)
                } else {
                    format!("{}", c)
                }
            })
            .collect();

        if self.end() {
            return write!(f, "{}[]", formatted_str);
        }

        write!(f, "{}", formatted_str)
    }
}

impl<T> FromIterator<T> for PeekableDeque<T> {
    fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Self {
        PeekableDeque {
            deque: iter.into_iter().collect(),
            index: 0,
        }
    }
}

impl<T: Clone> Iterator for PeekableDeque<T> {
    type Item = T;

    fn next(&mut self) -> Option<T> {
        self.index += 1;
        self.deque.get(self.index).cloned()
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_back_negative() {
        let query = "test".to_string();
        let mut peekable_query = PeekableDeque::from_iter(query.chars());

        peekable_query.next();
        peekable_query.next();
        peekable_query.back(5);

        assert_eq!('t', *peekable_query.peek().unwrap());
    }

    #[test]
    fn test_back_positive() {
        let query = "test".to_string();
        let mut peekable_query = PeekableDeque::from_iter(query.chars());

        peekable_query.next();
        peekable_query.next();
        peekable_query.back(1);

        assert_eq!('e', *peekable_query.peek().unwrap());
    }

    #[test]
    fn test_peek() {
        let query = "test".to_string();
        let peekable_query = PeekableDeque::from_iter(query.chars());

        if let Some(peeked_char) = peekable_query.peek() {
            if *peeked_char != 't' {
                panic!("Expected 't' char, but got {}", peeked_char);
            }
        } else {
            panic!("Expected 't' char, but got nothing");
        }
    }

    #[test]
    fn test_peek_when_empty() {
        let query = "".to_string();
        let peekable_query = PeekableDeque::from_iter(query.chars());

        if let Some(peeked_char) = peekable_query.peek() {
            panic!("Expected nothing, but got {}", peeked_char);
        }
    }

    #[test]
    fn test_next() {
        let query = "test".to_string();
        let mut peekable_query = PeekableDeque::from_iter(query.chars());

        assert_eq!('e', peekable_query.next().unwrap());
        assert_eq!('e', *peekable_query.peek().unwrap());
    }

    #[test]
    fn test_next_when_empty() {
        let query = "".to_string();
        let mut peekable_query = PeekableDeque::from_iter(query.chars());

        peekable_query.next();

        if let Some(peeked_char) = peekable_query.peek() {
            panic!("Expected nothing, but got {}", peeked_char);
        }
    }

    #[test]
    fn test_to_string() {
        let query = "test".to_string();
        let mut peekable_query = PeekableDeque::from_iter(query.chars());

        assert_eq!("[t]est", peekable_query.to_string());

        peekable_query.next();
        assert_eq!("t[e]st", peekable_query.to_string());

        peekable_query.next();
        assert_eq!("te[s]t", peekable_query.to_string());

        peekable_query.next();
        assert_eq!("tes[t]", peekable_query.to_string());
    }
}