Trait std::str::pattern::Pattern   [−][src]
pub trait Pattern<'a> {
    type Searcher: Searcher<'a>;
    fn into_searcher(self, haystack: &'a str) -> Self::Searcher;
    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)
API not fully fleshed out and ready to be stabilized
Expand description
A string pattern.
A Pattern<'a> expresses that the implementing type
can be used as a string pattern for searching in a &'a str.
For example, both 'a' and "aa" are patterns that
would match at index 1 in the string "baaaab".
The trait itself acts as a builder for an associated
Searcher type, which does the actual work of finding
occurrences of the pattern in a string.
Depending on the type of the pattern, the behaviour of methods like
str::find and str::contains can change. The table below describes
some of those behaviours.
| 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 | Freturnstruefor 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]
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);Associated Types
Required methods
fn 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)
API not fully fleshed out and ready to be stabilized
Constructs the associated searcher from
self and the haystack to search in.
Provided methods
fn 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)
API not fully fleshed out and ready to be stabilized
Checks whether the pattern matches anywhere in the haystack
fn 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)
API not fully fleshed out and ready to be stabilized
Checks whether the pattern matches at the front of the haystack
fn is_suffix_of(self, haystack: &'a str) -> bool where
    Self::Searcher: ReverseSearcher<'a>, 
fn is_suffix_of(self, haystack: &'a str) -> bool where
    Self::Searcher: ReverseSearcher<'a>, 
🔬 This is a nightly-only experimental API. (pattern #27721)
API not fully fleshed out and ready to be stabilized
Checks whether the pattern matches at the back of the haystack
fn 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)
API not fully fleshed out and ready to be stabilized
Removes the pattern from the front of haystack, if it matches.
fn 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)
API not fully fleshed out and ready to be stabilized
Removes the pattern from the back of haystack, if it matches.
Implementors
Searches for chars that are equal to a given char.
Examples
assert_eq!("Hello world".find('o'), Some(4));type Searcher = CharSearcher<'a>
Non-allocating substring search.
Will handle the pattern "" as returning empty matches at each character
boundary.
Examples
assert_eq!("Hello world".find("world"), Some(6));type Searcher = StrSearcher<'a, 'b>
Searches for chars that are equal to any of the chars in the slice.
Examples
assert_eq!("Hello world".find(&['l', 'l'] as &[_]), Some(2));
assert_eq!("Hello world".find(&['l', 'l'][..]), Some(2));