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>, { ... } }
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 |
F returns true for a char in string |
&&str |
is substring |
&String |
is substring |
// &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);
type Searcher: Searcher<'a>
Associated searcher for this pattern
fn into_searcher(self, haystack: &'a str) -> Self::Searcher
Constructs the associated searcher from self
and the haystack
to search in.
fn is_contained_in(self, haystack: &'a str) -> bool
Checks whether the pattern matches anywhere in the haystack
fn is_prefix_of(self, haystack: &'a str) -> bool
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>,
Checks whether the pattern matches at the back of the haystack
fn strip_prefix_of(self, haystack: &'a str) -> Option<&'a str>
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>,
Removes the pattern from the back of haystack, if it matches.
impl<'a> Pattern<'a> for char
[src]
Searches for chars that are equal to a given char
.
assert_eq!("Hello world".find('o'), Some(4));
type Searcher = CharSearcher<'a>
fn into_searcher(self, haystack: &'a str) -> <char as Pattern<'a>>::Searcher
[src]
fn is_contained_in(self, haystack: &'a str) -> bool
[src]
fn is_prefix_of(self, haystack: &'a str) -> bool
[src]
fn strip_prefix_of(self, haystack: &'a str) -> Option<&'a str>
[src]
fn is_suffix_of(self, haystack: &'a str) -> bool where
<char as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
[src]
fn strip_suffix_of(self, haystack: &'a str) -> Option<&'a str> where
<char as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
[src]
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.
assert_eq!("Hello world".find("world"), Some(6));
type Searcher = StrSearcher<'a, 'b>
fn into_searcher(self, haystack: &'a str) -> StrSearcher<'a, 'b>
[src]
fn is_prefix_of(self, haystack: &'a str) -> bool
[src]
Checks whether the pattern matches at the front of the haystack.
fn strip_prefix_of(self, haystack: &'a str) -> Option<&'a str>
[src]
Removes the pattern from the front of haystack, if it matches.
fn is_suffix_of(self, haystack: &'a str) -> bool
[src]
Checks whether the pattern matches at the back of the haystack.
fn strip_suffix_of(self, haystack: &'a str) -> Option<&'a str>
[src]
Removes the pattern from the back of haystack, if it matches.
impl<'a, 'b> Pattern<'a> for &'b String
[src]
A convenience impl that delegates to the impl for &str
.
assert_eq!(String::from("Hello world").find("world"), Some(6));
type Searcher = <&'b str as Pattern<'a>>::Searcher
fn into_searcher(self, haystack: &'a str) -> <&'b str as Pattern<'a>>::Searcher
[src]
fn is_contained_in(self, haystack: &'a str) -> bool
[src]
fn is_prefix_of(self, haystack: &'a str) -> bool
[src]
fn strip_prefix_of(self, haystack: &'a str) -> Option<&'a str>
[src]
fn is_suffix_of(self, haystack: &'a str) -> bool
[src]
fn strip_suffix_of(self, haystack: &'a str) -> Option<&'a str>
[src]
impl<'a, 'b> Pattern<'a> for &'b [char]
[src]
Searches for chars that are equal to any of the char
s in the slice.
assert_eq!("Hello world".find(&['l', 'l'] as &[_]), Some(2)); assert_eq!("Hello world".find(&['l', 'l'][..]), Some(2));
type Searcher = CharSliceSearcher<'a, 'b>
fn into_searcher(self, haystack: &'a str) -> CharSliceSearcher<'a, 'b>
[src]
fn is_contained_in(self, haystack: &'a str) -> bool
[src]
fn is_prefix_of(self, haystack: &'a str) -> bool
[src]
fn strip_prefix_of(self, haystack: &'a str) -> Option<&'a str>
[src]
fn is_suffix_of(self, haystack: &'a str) -> bool where
CharSliceSearcher<'a, 'b>: ReverseSearcher<'a>,
[src]
fn strip_suffix_of(self, haystack: &'a str) -> Option<&'a str> where
CharSliceSearcher<'a, 'b>: ReverseSearcher<'a>,
[src]
impl<'a, 'b, 'c> Pattern<'a> for &'c &'b str
[src]
Delegates to the &str
impl.
type Searcher = StrSearcher<'a, 'b>
fn into_searcher(self, haystack: &'a str) -> StrSearcher<'a, 'b>
[src]
fn is_contained_in(self, haystack: &'a str) -> bool
[src]
fn is_prefix_of(self, haystack: &'a str) -> bool
[src]
fn strip_prefix_of(self, haystack: &'a str) -> Option<&'a str>
[src]
fn is_suffix_of(self, haystack: &'a str) -> bool where
StrSearcher<'a, 'b>: ReverseSearcher<'a>,
[src]
fn strip_suffix_of(self, haystack: &'a str) -> Option<&'a str> where
StrSearcher<'a, 'b>: ReverseSearcher<'a>,
[src]
impl<'a, F> Pattern<'a> for F where
F: FnMut(char) -> bool,
[src]
Searches for char
s that match the given predicate.
assert_eq!("Hello world".find(char::is_uppercase), Some(0)); assert_eq!("Hello world".find(|c| "aeiou".contains(c)), Some(1));
type Searcher = CharPredicateSearcher<'a, F>
fn into_searcher(self, haystack: &'a str) -> CharPredicateSearcher<'a, F>
[src]
fn is_contained_in(self, haystack: &'a str) -> bool
[src]
fn is_prefix_of(self, haystack: &'a str) -> bool
[src]
fn strip_prefix_of(self, haystack: &'a str) -> Option<&'a str>
[src]
fn is_suffix_of(self, haystack: &'a str) -> bool where
CharPredicateSearcher<'a, F>: ReverseSearcher<'a>,
[src]
fn strip_suffix_of(self, haystack: &'a str) -> Option<&'a str> where
CharPredicateSearcher<'a, F>: ReverseSearcher<'a>,
[src]
© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/str/pattern/trait.Pattern.html