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'
和 "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::find
和 str::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 type | Match condition |
---|---|
&str | is substring |
char | is contained in string |
&[char] | any char in slice is contained in string |
F: FnMut(char) -> bool | F returns true for a char in string |
&&str | is substring |
&String | is 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);
RunRequired Associated Types§
Required Methods§
sourcefn into_searcher(self, haystack: &'a str) -> Self::Searcher
fn into_searcher(self, haystack: &'a str) -> Self::Searcher
🔬This is a nightly-only experimental API. (
pattern
#27721)从 self
和 haystack
构造关联的搜索器以进行搜索。
Provided Methods§
sourcefn is_contained_in(self, haystack: &'a str) -> bool
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
sourcefn is_prefix_of(self, haystack: &'a str) -> bool
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
sourcefn is_suffix_of(self, haystack: &'a str) -> boolwhere
Self::Searcher: ReverseSearcher<'a>,
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
sourcefn strip_prefix_of(self, haystack: &'a str) -> Option<&'a str>
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。
sourcefn strip_suffix_of(self, haystack: &'a str) -> Option<&'a str>where
Self::Searcher: ReverseSearcher<'a>,
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§
source§impl<'a, 'b> Pattern<'a> for &'b [char]
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));
Runtype Searcher = CharSliceSearcher<'a, 'b>
source§impl<'a, 'b, 'c> Pattern<'a> for &'c &'b str
impl<'a, 'b, 'c> Pattern<'a> for &'c &'b str
委托给 &str
的 impl。
type Searcher = StrSearcher<'a, 'b>
source§impl<'a, 'b, const N: usize> Pattern<'a> for &'b [char; N]
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