castep_cell_io/param/nmr/
magres_method.rs

1use castep_cell_fmt::{Cell, CellValue, ToCell, ToCellValue};
2use castep_cell_fmt::parse::{FromCellValue, FromKeyValue};
3use castep_cell_fmt::{CResult, Error};
4use castep_cell_fmt::query::value_as_str;
5
6/// Selects the method used by CASTEP for the evaluation of the quantum-mechanical position operator.
7///
8/// Keyword type: String
9///
10/// Default: MagresMethod::Crystal
11///
12/// Example:
13/// MAGRES_METHOD : molecular
14#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq)]
15#[derive(Default)]
16pub enum MagresMethod {
17    /// Uses the reciprocal space representation; applicable for both crystals and "molecule in a box"
18    #[default]
19    Crystal,
20    /// Applicable only for "molecule in a box"; faster calculation
21    Molecular,
22}
23
24
25impl FromCellValue for MagresMethod {
26    fn from_cell_value(value: &CellValue<'_>) -> CResult<Self> {
27        match value_as_str(value)?.to_ascii_lowercase().as_str() {
28            "crystal" => Ok(Self::Crystal),
29            "molecular" => Ok(Self::Molecular),
30            other => Err(Error::Message(format!("unknown MagresMethod: {other}"))),
31        }
32    }
33}
34
35impl FromKeyValue for MagresMethod {
36    const KEY_NAME: &'static str = "MAGRES_METHOD";
37
38    fn from_cell_value_kv(value: &CellValue<'_>) -> CResult<Self> {
39        Self::from_cell_value(value)
40    }
41}
42
43impl ToCell for MagresMethod {
44    fn to_cell(&self) -> Cell<'_> {
45        Cell::KeyValue("MAGRES_METHOD", self.to_cell_value())
46    }
47}
48
49impl ToCellValue for MagresMethod {
50    fn to_cell_value(&self) -> CellValue<'_> {
51        CellValue::String(
52            match self {
53                MagresMethod::Crystal => "Crystal",
54                MagresMethod::Molecular => "Molecular",
55            }
56            .to_string(),
57        )
58    }
59}
60
61#[cfg(test)]
62mod tests {
63    use super::*;
64    use castep_cell_fmt::CellValue;
65
66    #[test]
67    fn test_case_insensitive() {
68        assert_eq!(MagresMethod::from_cell_value(&CellValue::Str("crystal")).unwrap(), MagresMethod::Crystal);
69        assert_eq!(MagresMethod::from_cell_value(&CellValue::Str("CRYSTAL")).unwrap(), MagresMethod::Crystal);
70        assert_eq!(MagresMethod::from_cell_value(&CellValue::Str("molecular")).unwrap(), MagresMethod::Molecular);
71    }
72
73    #[test]
74    fn test_invalid() {
75        assert!(MagresMethod::from_cell_value(&CellValue::Str("invalid")).is_err());
76    }
77
78    #[test]
79    fn test_key_name() {
80        assert_eq!(MagresMethod::KEY_NAME, "MAGRES_METHOD");
81    }
82}
castep_cell_io/param/nmr/magres_method.rs

castep_cell_io/param/nmr/
magres_method.rs
