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

use crate::{Index, IndexVector, Indices};
use rand::{rngs::StdRng, Rng, SeedableRng};
use weresocool_error::{Error, IndexError};

impl Indices {
    pub fn vectorize(&self, len_list: usize) -> Result<Vec<IndexVector>, Error> {
        let mut result = vec![];

        for index in self.0.iter() {
            let index_vectors = index.vectorize(len_list)?;
            result.extend(index_vectors);
        }

        Ok(result)
    }
}

fn make_index_error(index: i64, len_list: usize) -> Option<Error> {
    if index < 0 {
        println!("negative index {} not yet supported.", index);
        return Some(
            IndexError {
                index,
                len_list,
                message: format!("negative index {} not yet supported", index),
            }
            .into_error(),
        );
    } else if index as usize >= len_list {
        println!(
            "index {} is greater than length of list {}",
            index, len_list
        );

        return Some(
            IndexError {
                index,
                len_list,
                message: format!(
                    "index {} is greater than length of list {}",
                    index, len_list
                ),
            }
            .into_error(),
        );
    }
    None
}

impl Index {
    pub fn vectorize(&self, len_list: usize) -> Result<Vec<IndexVector>, Error> {
        match self {
            Index::Const { indices } => indices
                .iter()
                .map(|i| {
                    let index_error = make_index_error(*i, len_list);
                    match index_error {
                        Some(e) => Err(e),
                        None => Ok(IndexVector {
                            index: *i as usize,
                            index_terms: vec![],
                        }),
                    }
                })
                .collect::<Result<Vec<IndexVector>, Error>>(),

            Index::Slice { start, end, skip } => {
                let a = match start {
                    Some(start) => {
                        let index_error = make_index_error(*start, len_list);
                        if let Some(e) = index_error {
                            return Err(e);
                        } else {
                            *start as usize
                        }
                    }
                    None => 0,
                };
                let b = match end {
                    Some(end) => {
                        let index_error = make_index_error(*end, len_list);
                        if let Some(e) = index_error {
                            return Err(e);
                        } else {
                            *end as usize
                        }
                    }
                    None => len_list - 1,
                };

                Ok(if a < b {
                    (a..=b).collect::<Vec<usize>>()
                } else {
                    (b..=a).rev().collect::<Vec<usize>>()
                }
                .iter()
                .enumerate()
                .filter_map(|(i, n)| {
                    if i % *skip as usize == 0 {
                        Some(IndexVector {
                            index: *n,
                            index_terms: vec![],
                        })
                    } else {
                        None
                    }
                })
                .collect())
            }
            Index::Random { n, seed } => {
                let mut rng: StdRng = SeedableRng::seed_from_u64(*seed as u64);
                Ok((0..*n)
                    .map(|_| {
                        let n: usize = rng.gen_range(0, len_list);
                        IndexVector {
                            index: n,
                            index_terms: vec![],
                        }
                    })
                    .collect())
            }
            Index::IndexAndTerm { index, term } => Ok(index
                .vectorize(len_list)?
                .iter_mut()
                .map(|index_vector| {
                    index_vector.index_terms.push(term.clone());
                    index_vector.to_owned()
                })
                .collect()),
        }
    }
}