1 | use super::{IntoRecords, Records}; |
2 | |
3 | /// A [Records] implementation for any [IntoIterator]. |
4 | #[derive (Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)] |
5 | pub struct IterRecords<I> { |
6 | iter: I, |
7 | count_columns: usize, |
8 | count_rows: Option<usize>, |
9 | } |
10 | |
11 | impl<I> IterRecords<I> { |
12 | /// Returns a new [IterRecords] object. |
13 | pub const fn new(iter: I, count_columns: usize, count_rows: Option<usize>) -> Self { |
14 | Self { |
15 | iter, |
16 | count_columns, |
17 | count_rows, |
18 | } |
19 | } |
20 | } |
21 | |
22 | impl<I> IntoRecords for IterRecords<I> |
23 | where |
24 | I: IntoRecords, |
25 | { |
26 | type Cell = I::Cell; |
27 | type IterColumns = I::IterColumns; |
28 | type IterRows = I::IterRows; |
29 | |
30 | fn iter_rows(self) -> Self::IterRows { |
31 | self.iter.iter_rows() |
32 | } |
33 | } |
34 | |
35 | // why this does not work? |
36 | |
37 | // impl<'a, I> IntoRecords for &'a IterRecords<I> |
38 | // where |
39 | // &'a I: IntoRecords, |
40 | // { |
41 | // type Cell = <&'a I as IntoRecords>::Cell; |
42 | // type IterColumns = <&'a I as IntoRecords>::IterColumns; |
43 | // type IterRows = <&'a I as IntoRecords>::IterRows; |
44 | |
45 | // fn iter_rows(self) -> Self::IterRows { |
46 | // // (&self.iter).iter_rows() |
47 | // todo!() |
48 | // } |
49 | // } |
50 | |
51 | impl<I> Records for IterRecords<I> |
52 | where |
53 | I: IntoRecords, |
54 | { |
55 | type Iter = I; |
56 | |
57 | fn iter_rows(self) -> <Self::Iter as IntoRecords>::IterRows { |
58 | self.iter.iter_rows() |
59 | } |
60 | |
61 | fn count_columns(&self) -> usize { |
62 | self.count_columns |
63 | } |
64 | |
65 | fn hint_count_rows(&self) -> Option<usize> { |
66 | self.count_rows |
67 | } |
68 | } |
69 | |
70 | impl<'a, I> Records for &'a IterRecords<I> |
71 | where |
72 | &'a I: IntoRecords, |
73 | { |
74 | type Iter = &'a I; |
75 | |
76 | fn iter_rows(self) -> <Self::Iter as IntoRecords>::IterRows { |
77 | (&self.iter).iter_rows() |
78 | } |
79 | |
80 | fn count_columns(&self) -> usize { |
81 | self.count_columns |
82 | } |
83 | |
84 | fn hint_count_rows(&self) -> Option<usize> { |
85 | self.count_rows |
86 | } |
87 | } |
88 | |