fosk 0.1.3

In-memory SQL-like query engine and lightweight data store for testing and prototyping.
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

#[derive(Clone, Copy, PartialEq, Eq)]
pub enum Truth {
    True,
    False,
    Unknown
}

impl Truth {
    pub fn not(&self) -> Self {
        match self {
            Self::True => Self::False,
            Self::False => Self::True,
            Self::Unknown => Self::Unknown
        }
    }

    pub fn and(&self, b: Self) -> Self {
        match (self, b) {
            (Self::False, _) | (_, Self::False) => Self::False,
            (Self::Unknown, _) | (_, Self::Unknown) => Self::Unknown,
            (Self::True, Self::True) => Self::True,
        }
    }

    pub fn or(&self, b: Self) -> Self {
        match (self, b) {
            (Self::True, _) | (_, Self::True) => Self::True,
            (Self::Unknown, _) | (_, Self::Unknown) => Self::Unknown,
            (Self::False, Self::False) => Self::False,
        }
    }
}

use std::fmt;

impl fmt::Display for Truth {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Self::True => write!(f, "True"),
            Self::False => write!(f, "False"),
            Self::Unknown => write!(f, "Unknown"),
        }
    }
}

impl fmt::Debug for Truth {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "Truth({})", self)
    }
}