scratchstack_aspen/condition/
variant.rs

1/// The variant on an operation.
2///
3/// The offsets used in the representation are used to index into the operation names.
4#[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
5#[repr(u8)]
6pub enum Variant {
7    /// No variation on the basic operation.
8    None = 0,
9
10    /// IfExists variant.
11    IfExists = 1,
12
13    /// Negated: Equals => NotEquals, LessThan => GreaterThanEquals, etc.
14    Negated = 2,
15
16    /// IfExists and Negated.
17    IfExistsNegated = 3,
18}
19
20impl Variant {
21    /// Return the index into the operation names for this variant.
22    #[inline]
23    pub(super) fn as_usize(self) -> usize {
24        self as usize
25    }
26
27    /// Indicates if this is [Variant::IfExists] or [Variant::IfExistsNegated].
28    #[inline]
29    pub(super) fn if_exists(self) -> bool {
30        matches!(self, Self::IfExists | Self::IfExistsNegated)
31    }
32
33    /// Indicates if this is [Variant::Negated] or [Variant::IfExistsNegated].
34    #[inline]
35    pub(super) fn negated(self) -> bool {
36        matches!(self, Self::Negated | Self::IfExistsNegated)
37    }
38}
39
40impl From<u8> for Variant {
41    fn from(value: u8) -> Self {
42        match value {
43            0 => Self::None,
44            1 => Self::IfExists,
45            2 => Self::Negated,
46            3 => Self::IfExistsNegated,
47            _ => panic!("Invalid variant value: {value}"),
48        }
49    }
50}
51
52#[cfg(test)]
53mod tests {
54    use {super::Variant, pretty_assertions::assert_eq, std::panic::catch_unwind};
55
56    #[test_log::test]
57    fn test_clone() {
58        assert_eq!(Variant::None.clone(), Variant::None);
59        assert_eq!(Variant::IfExists.clone(), Variant::IfExists);
60        assert_eq!(Variant::Negated.clone(), Variant::Negated);
61        assert_eq!(Variant::IfExistsNegated.clone(), Variant::IfExistsNegated);
62    }
63
64    #[test_log::test]
65    fn test_variant_values() {
66        assert_eq!(Variant::None, Variant::from(0));
67        assert_eq!(Variant::IfExists, Variant::from(1));
68        assert_eq!(Variant::Negated, Variant::from(2));
69        assert_eq!(Variant::IfExistsNegated, Variant::from(3));
70
71        let e = catch_unwind(|| Variant::from(4)).unwrap_err();
72        assert_eq!(e.downcast_ref::<String>().unwrap(), "Invalid variant value: 4");
73    }
74}
scratchstack_aspen/condition/variant.rs

scratchstack_aspen/condition/
variant.rs
