28 lines
899 B
Rust
28 lines
899 B
Rust
use core::iter::*;
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#[test]
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fn test_map_try_folds() {
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let f = &|acc, x| i32::checked_add(2 * acc, x);
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assert_eq!((0..10).map(|x| x + 3).try_fold(7, f), (3..13).try_fold(7, f));
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assert_eq!((0..10).map(|x| x + 3).try_rfold(7, f), (3..13).try_rfold(7, f));
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let mut iter = (0..40).map(|x| x + 10);
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assert_eq!(iter.try_fold(0, i8::checked_add), None);
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assert_eq!(iter.next(), Some(20));
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assert_eq!(iter.try_rfold(0, i8::checked_add), None);
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assert_eq!(iter.next_back(), Some(46));
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}
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#[test]
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fn test_double_ended_map() {
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let xs = [1, 2, 3, 4, 5, 6];
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let mut it = xs.iter().map(|&x| x * -1);
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assert_eq!(it.next(), Some(-1));
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assert_eq!(it.next(), Some(-2));
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assert_eq!(it.next_back(), Some(-6));
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assert_eq!(it.next_back(), Some(-5));
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assert_eq!(it.next(), Some(-3));
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assert_eq!(it.next_back(), Some(-4));
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assert_eq!(it.next(), None);
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}
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