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
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190

use std::fmt::{Display, Formatter, Result as FmtResult};

pub struct Portion;

impl Portion {
    pub fn open<T: Sized + PartialOrd + Display>(lower: T, upper: T) -> Open<T> {
        Open { lower, upper }
    }
    pub fn closed<T: Sized + PartialOrd + Display>(lower: T, upper: T) -> Closed<T> {
        Closed { lower, upper }
    }
    pub fn empty() -> Empty {
        Empty
    }
    pub fn singleton<T: Sized + PartialOrd + Display>(value: T) -> Singleton<T> {
        Singleton { value }
    }
    pub fn openclosed<T: Sized + PartialOrd + Display>(lower: T, upper: T) -> OpenClosed<T> {
        OpenClosed { lower, upper }
    }
    pub fn closedopen<T: Sized + PartialOrd + Display>(lower: T, upper: T) -> ClosedOpen<T> {
        ClosedOpen { lower, upper }
    }
}

trait Interval {
    fn empty(&self) -> bool {
        true
    }
    fn atomic(&self) -> bool {
        true
    }
    fn itype(&self) -> IntervalType {
        IntervalType::Empty
    }
}

pub enum IntervalType {
    Open,
    Closed,
    Empty,
    Singleton,
    OpenClosed,
    ClosedOpen,
}

pub struct Open<T: Sized + PartialOrd + Display> {
    lower: T,
    upper: T,
}

impl<T: Sized + PartialOrd + Display> Display for Open<T> {
    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
        if self.empty() {
            return write!(f, "()");
        }

        write!(f, "({}, {})", self.lower, self.upper)
    }
}

impl<T: Sized + PartialOrd + Display> Interval for Open<T> {
    fn empty(&self) -> bool {
        self.lower >= self.upper
    }

    fn atomic(&self) -> bool {
        true
    }
    fn itype(&self) -> IntervalType {
        IntervalType::Open
    }
}

pub struct Closed<T: Sized + PartialOrd + Display> {
    lower: T,
    upper: T,
}

impl<T: Sized + PartialOrd + Display> Display for Closed<T> {
    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
        if self.empty() {
            return write!(f, "()");
        }

        if self.lower == self.upper {
            write!(f, "[{}]", self.lower)
        } else {
            write!(f, "[{}, {}]", self.lower, self.upper)
        }
    }
}

impl<T: Sized + PartialOrd + Display> Interval for Closed<T> {
    fn empty(&self) -> bool {
        self.lower > self.upper
    }

    fn atomic(&self) -> bool {
        true
    }
    fn itype(&self) -> IntervalType {
        IntervalType::Closed
    }
}

pub struct Empty;

impl Interval for Empty {}

impl Display for Empty {
    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
        write!(f, "()")
    }
}

pub struct Singleton<T: Sized + PartialOrd + Display> {
    value: T,
}

impl<T: Sized + PartialOrd + Display> Interval for Singleton<T> {
    fn empty(&self) -> bool {
        false
    }
    fn atomic(&self) -> bool {
        true
    }
    fn itype(&self) -> IntervalType {
        IntervalType::Singleton
    }
}

impl<T: Sized + PartialOrd + Display> Display for Singleton<T> {
    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
        write!(f, "[{}]", self.value)
    }
}

pub struct OpenClosed<T: Sized + PartialOrd + Display> {
    lower: T,
    upper: T,
}

impl<T: Sized + PartialOrd + Display> Display for OpenClosed<T> {
    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
        if self.empty() {
            return write!(f, "(]");
        }
        write!(f, "({}, {}]", self.lower, self.upper)
    }
}

impl<T: Sized + PartialOrd + Display> Interval for OpenClosed<T> {
    fn empty(&self) -> bool {
        self.lower >= self.upper
    }

    fn atomic(&self) -> bool {
        true
    }
    fn itype(&self) -> IntervalType {
        IntervalType::OpenClosed
    }
}

pub struct ClosedOpen<T: Sized + PartialOrd + Display> {
    lower: T,
    upper: T,
}

impl<T: Sized + PartialOrd + Display> Display for ClosedOpen<T> {
    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
        if self.empty() {
            return write!(f, "[)");
        }
        write!(f, "[{}, {})", self.lower, self.upper)
    }
}

impl<T: Sized + PartialOrd + Display> Interval for ClosedOpen<T> {
    fn empty(&self) -> bool {
        self.lower >= self.upper
    }
    fn atomic(&self) -> bool {
        true
    }
    fn itype(&self) -> IntervalType {
        IntervalType::ClosedOpen
    }
}