[][src]Trait core::str::pattern::Pattern

pub trait Pattern<'a>: Sized {
    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

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 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]
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

Associated Types

type Searcher: Searcher<'a>

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

API not fully fleshed out and ready to be stabilized

Associated searcher for this pattern

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Required methods

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.

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Provided methods

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

🔬 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>, 

🔬 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>

🔬 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>, 

🔬 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.

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Implementors

impl<'a> Pattern<'a> for char[src]

Searches for chars that are equal to a given char.

Examples

assert_eq!("Hello world".find('o'), Some(4));
Run

type Searcher = CharSearcher<'a>

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

API not fully fleshed out and ready to be stabilized

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

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));
Run

type Searcher = CharSliceSearcher<'a, 'b>

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

API not fully fleshed out and ready to be stabilized

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

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));
Run

type Searcher = StrSearcher<'a, 'b>

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

API not fully fleshed out and ready to be stabilized

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

🔬 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 strip_prefix_of(self, haystack: &'a str) -> Option<&'a str>[src]

🔬 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 is_suffix_of(self, haystack: &'a str) -> bool[src]

🔬 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_suffix_of(self, haystack: &'a str) -> Option<&'a str>[src]

🔬 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.

impl<'a, 'b, 'c> Pattern<'a> for &'c &'b str[src]

Delegates to the &str impl.

type Searcher = StrSearcher<'a, 'b>

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

API not fully fleshed out and ready to be stabilized

impl<'a, F> Pattern<'a> for F where
    F: FnMut(char) -> bool, 
[src]

Searches for chars that match the given predicate.

Examples

assert_eq!("Hello world".find(char::is_uppercase), Some(0));
assert_eq!("Hello world".find(|c| "aeiou".contains(c)), Some(1));
Run

type Searcher = CharPredicateSearcher<'a, F>

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

API not fully fleshed out and ready to be stabilized

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