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

// This file is part of the uutils coreutils package.
//
// (c) Rolf Morel <rolfmorel@gmail.com>
//
// For the full copyright and license information, please view the LICENSE
// file that was distributed with this source code.

// spell-checker:ignore (ToDO) inval

use std::str::FromStr;

#[derive(PartialEq, Eq, PartialOrd, Ord, Debug)]
pub struct Range {
    pub low: usize,
    pub high: usize,
}

impl FromStr for Range {
    type Err = &'static str;

    fn from_str(s: &str) -> Result<Range, &'static str> {
        use std::usize::MAX;

        let mut parts = s.splitn(2, '-');

        let field = "fields and positions are numbered from 1";
        let order = "high end of range less than low end";
        let inval = "failed to parse range";

        match (parts.next(), parts.next()) {
            (Some(nm), None) => {
                if let Ok(nm) = nm.parse::<usize>() {
                    if nm > 0 {
                        Ok(Range { low: nm, high: nm })
                    } else {
                        Err(field)
                    }
                } else {
                    Err(inval)
                }
            }
            (Some(n), Some(m)) if m.is_empty() => {
                if let Ok(low) = n.parse::<usize>() {
                    if low > 0 {
                        Ok(Range { low, high: MAX - 1 })
                    } else {
                        Err(field)
                    }
                } else {
                    Err(inval)
                }
            }
            (Some(n), Some(m)) if n.is_empty() => {
                if let Ok(high) = m.parse::<usize>() {
                    if high > 0 {
                        Ok(Range { low: 1, high })
                    } else {
                        Err(field)
                    }
                } else {
                    Err(inval)
                }
            }
            (Some(n), Some(m)) => match (n.parse::<usize>(), m.parse::<usize>()) {
                (Ok(low), Ok(high)) => {
                    if low > 0 && low <= high {
                        Ok(Range { low, high })
                    } else if low == 0 {
                        Err(field)
                    } else {
                        Err(order)
                    }
                }
                _ => Err(inval),
            },
            _ => unreachable!(),
        }
    }
}

impl Range {
    pub fn from_list(list: &str) -> Result<Vec<Range>, String> {
        use std::cmp::max;

        let mut ranges: Vec<Range> = vec![];

        for item in list.split(',') {
            match FromStr::from_str(item) {
                Ok(range_item) => ranges.push(range_item),
                Err(e) => return Err(format!("range '{}' was invalid: {}", item, e)),
            }
        }

        ranges.sort();

        // merge overlapping ranges
        for i in 0..ranges.len() {
            let j = i + 1;

            while j < ranges.len() && ranges[j].low <= ranges[i].high {
                let j_high = ranges.remove(j).high;
                ranges[i].high = max(ranges[i].high, j_high);
            }
        }

        Ok(ranges)
    }
}

pub fn complement(ranges: &[Range]) -> Vec<Range> {
    use std::usize;

    let mut complements = Vec::with_capacity(ranges.len() + 1);

    if !ranges.is_empty() && ranges[0].low > 1 {
        complements.push(Range {
            low: 1,
            high: ranges[0].low - 1,
        });
    }

    let mut ranges_iter = ranges.iter().peekable();
    loop {
        match (ranges_iter.next(), ranges_iter.peek()) {
            (Some(left), Some(right)) => {
                if left.high + 1 != right.low {
                    complements.push(Range {
                        low: left.high + 1,
                        high: right.low - 1,
                    });
                }
            }
            (Some(last), None) => {
                if last.high < usize::MAX - 1 {
                    complements.push(Range {
                        low: last.high + 1,
                        high: usize::MAX - 1,
                    });
                }
            }
            _ => break,
        }
    }

    complements
}

/// Test if at least one of the given Ranges contain the supplied value.
///
/// Examples:
///
/// ```
/// let ranges = uucore::ranges::Range::from_list("11,2,6-8").unwrap();
///
/// assert!(!uucore::ranges::contain(&ranges, 0));
/// assert!(!uucore::ranges::contain(&ranges, 1));
/// assert!(!uucore::ranges::contain(&ranges, 5));
/// assert!(!uucore::ranges::contain(&ranges, 10));
///
/// assert!(uucore::ranges::contain(&ranges, 2));
/// assert!(uucore::ranges::contain(&ranges, 6));
/// assert!(uucore::ranges::contain(&ranges, 7));
/// assert!(uucore::ranges::contain(&ranges, 8));
/// assert!(uucore::ranges::contain(&ranges, 11));
/// ```
pub fn contain(ranges: &[Range], n: usize) -> bool {
    for range in ranges {
        if n >= range.low && n <= range.high {
            return true;
        }
    }

    false
}