Trait alloc::str::pattern::Pattern

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pub trait Pattern<'a>: Sized {
    type Searcher: Searcher<'a>;

    // Required method
    fn into_searcher(self, haystack: &'a str) -> Self::Searcher;

    // Provided methods
    fn is_contained_in(self, haystack: &'a str) -> bool { ... }
    fn is_prefix_of(self, haystack: &'a str) -> bool { ... }
    fn is_suffix_of(self, haystack: &'a str) -> bool
       where Self::Searcher: ReverseSearcher<'a> { ... }
    fn strip_prefix_of(self, haystack: &'a str) -> Option<&'a str> { ... }
    fn strip_suffix_of(self, haystack: &'a str) -> Option<&'a str>
       where Self::Searcher: ReverseSearcher<'a> { ... }
}
🔬This is a nightly-only experimental API. (pattern #27721)
Expand description

字符串模式。

Pattern<'a> 表示实现类型可以用作在 &'a str 中搜索的字符串模式。

例如,'a'"aa" 都是在字符串 "baaaab" 中的索引 1 处匹配的模式。

这个 trait 本身充当关联的 Searcher 类型的构建器,该类型执行在字符串中查找模式的实际工作。

根据模式的类型,诸如 str::findstr::contains 之类的方法的行为可能会改变。 下表描述了其中一些行为。

Pattern typeMatch condition
&stris substring
charis contained in string
&[char]any char in slice is contained in string
F: FnMut(char) -> boolF returns true for a char in string
&&stris substring
&Stringis substring

Examples

// &str
assert_eq!("abaaa".find("ba"), Some(1));
assert_eq!("abaaa".find("bac"), None);

// char
assert_eq!("abaaa".find('a'), Some(0));
assert_eq!("abaaa".find('b'), Some(1));
assert_eq!("abaaa".find('c'), None);

// &[char; N]
assert_eq!("ab".find(&['b', 'a']), Some(0));
assert_eq!("abaaa".find(&['a', 'z']), Some(0));
assert_eq!("abaaa".find(&['c', 'd']), None);

// &[char]
assert_eq!("ab".find(&['b', 'a'][..]), Some(0));
assert_eq!("abaaa".find(&['a', 'z'][..]), Some(0));
assert_eq!("abaaa".find(&['c', 'd'][..]), None);

// FnMut(char) -> bool
assert_eq!("abcdef_z".find(|ch| ch > 'd' && ch < 'y'), Some(4));
assert_eq!("abcddd_z".find(|ch| ch > 'd' && ch < 'y'), None);
Run

Required Associated Types§

source

type Searcher: Searcher<'a>

🔬This is a nightly-only experimental API. (pattern #27721)

此模式的关联搜索者

Required Methods§

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fn into_searcher(self, haystack: &'a str) -> Self::Searcher

🔬This is a nightly-only experimental API. (pattern #27721)

selfhaystack 构造关联的搜索器以进行搜索。

Provided Methods§

source

fn is_contained_in(self, haystack: &'a str) -> bool

🔬This is a nightly-only experimental API. (pattern #27721)

检查模式是否与 haystack 中的任何位置匹配

source

fn is_prefix_of(self, haystack: &'a str) -> bool

🔬This is a nightly-only experimental API. (pattern #27721)

检查模式是否在 haystack 的前面匹配

source

fn is_suffix_of(self, haystack: &'a str) -> boolwhere Self::Searcher: ReverseSearcher<'a>,

🔬This is a nightly-only experimental API. (pattern #27721)

检查模式是否与 haystack 的后面匹配

source

fn strip_prefix_of(self, haystack: &'a str) -> Option<&'a str>

🔬This is a nightly-only experimental API. (pattern #27721)

如果匹配,则从 haystack 的正面删除模式。

source

fn strip_suffix_of(self, haystack: &'a str) -> Option<&'a str>where Self::Searcher: ReverseSearcher<'a>,

🔬This is a nightly-only experimental API. (pattern #27721)

如果匹配,则从 haystack 的后面删除模式。

Implementors§

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impl<'a> Pattern<'a> for char

搜索等于给定 char 的字符。

Examples

assert_eq!("Hello world".find('o'), Some(4));
Run
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impl<'a, 'b> Pattern<'a> for &'b str

非分配子字符串搜索。

将模式 "" 处理为在每个字符边界处返回空匹配项。

Examples

assert_eq!("Hello world".find("world"), Some(6));
Run
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type Searcher = StrSearcher<'a, 'b>

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impl<'a, 'b> Pattern<'a> for &'b String

一个方便的 impl,委派给 &str 的 impl。

Examples

assert_eq!(String::from("Hello world").find("world"), Some(6));
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type Searcher = <&'b str as Pattern<'a>>::Searcher

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impl<'a, 'b> Pattern<'a> for &'b [char]

搜索等于切片中任何 char 的字符。

Examples

assert_eq!("Hello world".find(&['l', 'l'] as &[_]), Some(2));
assert_eq!("Hello world".find(&['l', 'l'][..]), Some(2));
Run
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impl<'a, 'b, 'c> Pattern<'a> for &'c &'b str

委托给 &str 的 impl。

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type Searcher = StrSearcher<'a, 'b>

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impl<'a, 'b, const N: usize> Pattern<'a> for &'b [char; N]

搜索等于数组中任何 char 的字符。

Examples

assert_eq!("Hello world".find(&['o', 'l']), Some(2));
assert_eq!("Hello world".find(&['h', 'w']), Some(6));
Run
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impl<'a, F> Pattern<'a> for Fwhere F: FnMut(char) -> bool,

搜索与给定谓词匹配的 char

Examples

assert_eq!("Hello world".find(char::is_uppercase), Some(0));
assert_eq!("Hello world".find(|c| "aeiou".contains(c)), Some(1));
Run
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impl<'a, const N: usize> Pattern<'a> for [char; N]

搜索等于数组中任何 char 的字符。

Examples

assert_eq!("Hello world".find(['o', 'l']), Some(2));
assert_eq!("Hello world".find(['h', 'w']), Some(6));
Run