rbe/
min.rs

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
use core::fmt;

use serde::de;
use serde::de::Visitor;
use serde::Deserialize;
use serde::Deserializer;
use serde::Serialize;
use serde::Serializer;

/// Represents a min cardinality which must be a 0 or positive integer.
#[derive(PartialEq, Eq, Hash, PartialOrd, Debug, Clone, Copy)]
pub struct Min {
    pub value: usize,
}

impl Min {
    pub fn is_0(&self) -> bool {
        self.value == 0
    }
}

impl From<usize> for Min {
    fn from(v: usize) -> Self {
        Min { value: v }
    }
}

impl From<i32> for Min {
    fn from(v: i32) -> Self {
        Min { value: v as usize }
    }
}

impl From<i8> for Min {
    fn from(v: i8) -> Self {
        Min { value: v as usize }
    }
}

impl From<i64> for Min {
    fn from(v: i64) -> Self {
        Min { value: v as usize }
    }
}

impl From<u64> for Min {
    fn from(v: u64) -> Self {
        Min { value: v as usize }
    }
}

impl Serialize for Min {
    fn serialize<S>(&self, serializer: S) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error>
    where
        S: Serializer,
    {
        let value = self.value as u128;
        serializer.serialize_u128(value)
    }
}

struct MinVisitor;

impl<'de> Visitor<'de> for MinVisitor {
    type Value = Min;

    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
        formatter.write_str("a positive integer")
    }

    fn visit_i8<E>(self, value: i8) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        if value < -1 {
            Err(E::custom(format!(
                "value of type i8 {} should be -1 or positive",
                value
            )))
        } else {
            let n = Min::from(value);
            Ok(n)
        }
    }

    fn visit_i32<E>(self, value: i32) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        if value < -1 {
            Err(E::custom(format!(
                "value of type i32 {} should be -1 or positive",
                value
            )))
        } else {
            Ok(Min::from(value))
        }
    }

    fn visit_i64<E>(self, value: i64) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        if value < -1 {
            Err(E::custom(format!(
                "value of type i64 {} should be -1 or positive",
                value
            )))
        } else {
            Ok(Min::from(value))
        }
    }

    fn visit_u64<E>(self, value: u64) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Min::from(value))
    }
}

impl<'de> Deserialize<'de> for Min {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: Deserializer<'de>,
    {
        deserializer.deserialize_i32(MinVisitor)
    }
}

#[cfg(test)]
mod tests {
    // use serde_json::*;
    // use serde::Serialize;

    use crate::Min;

    #[test]
    fn test_serialize_min() {
        let min = Min::from(23);
        let str = serde_json::to_string(&min).unwrap();
        assert_eq!(str, "23");
    }

    #[test]
    fn test_deserialize_min() {
        let min = Min::from(23);
        let min_deser = serde_json::from_str("23").unwrap();
        assert_eq!(min, min_deser);
    }
}