enum-conversion-derive 0.0.1

Prodedural macros for deriving From and TryFrom traits on enums.
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

use super::*;

pub(crate) fn templater() -> Tera {
    let mut tera = Tera::new("/dev/null/*").unwrap();
    tera.add_raw_template("get_variant", GET_VARIANT_TEMPLATE)
        .unwrap();
    tera.add_raw_template("try_from", TRY_FROM_TEMPLATE)
        .unwrap();
    tera.add_raw_template("try_to", TRY_TO_TEMPLATE).unwrap();
    tera.add_raw_template("from", FROM_TEMPLATE).unwrap();
    tera
}

pub(crate) const GET_VARIANT_TEMPLATE: &str = r#"
impl{{ generics }} enum_conversion_traits::GetVariant<{{ Type }}, {{ Marker }} > for {{ fullname }}
{{ Where }} {
    #[allow(unreachable_patterns)]
    fn get_variant(self) -> std::result::Result<{{ Type }}, enum_conversion_traits::EnumConversionError> {
        match self {
            {{ name }}::{{ field }}(inner) => Ok(inner),
            _ => Err(enum_conversion_traits::EnumConversionError::new("{{ fullname }}", "{{ Type }}"))
        }
    }

    #[allow(unreachable_patterns)]
    fn get_variant_ref(&self) -> std::result::Result<&{{ Type }}, enum_conversion_traits::EnumConversionError> {
        match &self {
            {{ name }}::{{ field }}(inner) => Ok(inner),
            _ => Err(enum_conversion_traits::EnumConversionError::new("{{ fullname }}", "{{ Type }}"))
        }
    }

    #[allow(unreachable_patterns)]
    fn get_variant_mut(&mut self) -> std::result::Result<&mut {{ Type }}, enum_conversion_traits::EnumConversionError> {
        match self {
            {{ name }}::{{ field }}(inner) => Ok(inner),
            _  => Err(enum_conversion_traits::EnumConversionError::new("{{ fullname }}", "{{ Type }}"))
        }
    }
}
"#;

pub(crate) const TRY_TO_TEMPLATE: &str = r#"
impl{{ generics }} TryTo<{{ Type }}> for {{ fullname }}
{{ Where }}
{
    type Error = {{ Error }};

    fn try_to(self) -> std::result::Result<{{ Type }}, Self::Error> {
        self.get_variant(){{ Map_Err }}
    }
}

impl{{ generics_ref }} TryTo<&{{ Lifetime }} {{ Type }}> for &{{ Lifetime }} {{ fullname }}
{{ Where }}
{
    type Error = {{ Error }};

    fn try_to(self) -> std::result::Result<&{{ Lifetime }} {{ Type }}, Self::Error> {
        self.get_variant_ref(){{ Map_Err }}
    }
}

impl{{ generics_ref }} TryTo<&{{ Lifetime }} mut {{ Type }}> for &{{ Lifetime }} mut {{ fullname }}
{{ Where }}
{

    type Error = {{ Error }};

    fn try_to(self) -> std::result::Result<&{{ Lifetime }} mut {{ Type }}, Self::Error> {
        self.get_variant_mut(){{ Map_Err }}
    }
}
"#;

pub(crate) const TRY_FROM_TEMPLATE: &str = r#"
impl{{ generics }} TryFrom<{{ fullname }}> for {{ Type }}
{{ Where }}
{
    type Error = {{ Error }};

    fn try_from(value: {{ fullname }}) -> std::result::Result<Self, Self::Error> {
        value.try_to()
    }
}

impl{{ generics_ref }} TryFrom<&{{ Lifetime }} {{ fullname }}> for &{{ Lifetime}} {{ Type }}
{{ Where }}
{
    type Error = {{ Error }};

    fn try_from(value: &{{ Lifetime }} {{ fullname }}) -> std::result::Result<Self, Self::Error> {
        value.try_to()

    }
}

impl{{ generics_ref }} TryFrom<&{{ Lifetime }} mut {{ fullname }}> for &{{ Lifetime }} mut {{ Type }}
{{ Where }}
{
    type Error = {{ Error }};

    fn try_from(value: &{{ Lifetime }} mut {{ fullname }}) -> std::result::Result<Self, Self::Error> {
        value.try_to()
    }
}
"#;

pub(crate) const FROM_TEMPLATE: &str = r#"
impl{{ generics }} From<{{ Type }}> for {{ fullname }}
{{ Where }}
{
    fn from(value: {{ Type }}) -> Self {
        Self::{{ field }}(value)
    }
}
"#;