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


#[derive(Debug, PartialEq)]
pub enum DimError {
    IndexMismatch,
    IndexOutOfRange,
}

#[derive(Debug, Clone)]
pub struct MultiDim<T: Clone> {
    dimensions: Vec<usize>,
    data: Vec<T>,
}

impl<T: Clone> MultiDim<T> {
    pub fn new(dim: &[usize], init: T) -> Self {
        let vect_dim: Vec<usize> = dim.iter().cloned().map(|x| x + 1).collect();
        let length: usize = vect_dim.iter().product();

        if dim.iter().min() == Some(&0) {
            panic!("Cannot have a 0-length dimension");
        }

        // println!("MultiDim new: {:?}", dim);
        MultiDim {
            dimensions: vect_dim,
            data: vec![init; length],
        }
    }

    fn out_of_range(&self, dim: &[usize]) -> bool {
        let iter = dim.iter().zip(self.dimensions.iter());
        for (a, b) in iter {
            if a > b {
                return true;
            }
        }
        false
    }

    fn check(&self, dim: &[usize]) -> Result<(), DimError> {
        if self.dimensions.len() != dim.len() {
            return Err(DimError::IndexMismatch);
        }

        if self.out_of_range(dim) {
            return Err(DimError::IndexOutOfRange);
        }

        Ok(())
    }

    fn index(&self, dim: &[usize]) -> usize {
        let mut n = 0;
        let mut mult = 1;
        for i in 0..dim.len() {
            n = n + (dim[i] * mult);
            mult = mult * self.dimensions[i];
        }
        n
    }

    pub fn set(&mut self, dim: &[usize], val: T) -> Result<(), DimError> {
        match self.check(dim) {
            Ok(_) => {
                let i = self.index(dim);
                self.data[i] = val;
                Ok(())
            }
            Err(e) => Err(e),
        }
    }

    pub fn get(&self, dim: &[usize]) -> Result<&T, DimError> {
        // println!("MultiDim get {:?}", dim);
        match self.check(dim) {
            Ok(_) => {
                let i = self.index(dim);
                Ok(&self.data[i])
            }
            Err(e) => Err(e),
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn set_and_get() {
        let mut md = MultiDim::<u32>::new(&[10, 10, 10], 0);
        for i in 0..10 {
            for j in 0..10 {
                for k in 0..10 {
                    md.set(&[i, j, k], (i + (j * 11) + (k * 121)) as u32).unwrap();
                }
            }
        }

        for i in 0..10 {
            for j in 0..10 {
                for k in 0..10 {
                    match md.get(&[i, j, k]) {
                        Ok(n) => assert_eq!(*n, (i + (j * 11) + (k * 121)) as u32),
                        Err(e) => panic!("Got error: {:?}", e),
                    }
                }
            }
        }
    }

    #[test]
    fn string_value() {
        let mut md = MultiDim::<String>::new(&[2, 2], String::from(""));
        md.set(&[0, 1], String::from("hello world")).unwrap();
        assert_eq!("", *md.get(&[0, 0]).unwrap());
        assert_eq!("hello world", *md.get(&[0, 1]).unwrap());
    }

    #[test]
    fn index_errors() {
        let mut md = MultiDim::<u32>::new(&[2, 2], 0);
        match md.set(&[5, 5], 0) {
            Ok(_) => assert!(false),
            Err(e) => assert_eq!(e, DimError::IndexOutOfRange),
        }

        match md.set(&[0, 0, 2], 0) {
            Ok(_) => assert!(false),
            Err(e) => assert_eq!(e, DimError::IndexMismatch),
        }

        match md.get(&[5, 5]) {
            Ok(_) => assert!(false),
            Err(e) => assert_eq!(e, DimError::IndexOutOfRange),
        }

        match md.get(&[0, 0, 2]) {
            Ok(_) => assert!(false),
            Err(e) => assert_eq!(e, DimError::IndexMismatch),
        }
    }

    #[test]
    #[should_panic]
    fn construct_failure() {
        MultiDim::<u32>::new(&[2, 0], 0);
    }
}