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37 lines
1.0 KiB
37 lines
1.0 KiB
3 years ago
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// ANCHOR: here
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fn first_word(s: &str) -> &str {
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// ANCHOR_END: here
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let bytes = s.as_bytes();
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for (i, &item) in bytes.iter().enumerate() {
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if item == b' ' {
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return &s[0..i];
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}
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}
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&s[..]
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}
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// ANCHOR: usage
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fn main() {
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let my_string = String::from("hello world");
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// `first_word` works on slices of `String`s, whether partial or whole
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let word = first_word(&my_string[0..6]);
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let word = first_word(&my_string[..]);
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// `first_word` also works on references to `String`s, which are equivalent
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// to whole slices of `String`s
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let word = first_word(&my_string);
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let my_string_literal = "hello world";
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// `first_word` works on slices of string literals, whether partial or whole
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let word = first_word(&my_string_literal[0..6]);
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let word = first_word(&my_string_literal[..]);
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// Because string literals *are* string slices already,
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// this works too, without the slice syntax!
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let word = first_word(my_string_literal);
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}
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// ANCHOR_END: usage
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