Trait regex::Replacer
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pub trait Replacer { fn replace_append(&mut self, caps: &Captures, dst: &mut String); fn no_expansion<'r>(&'r mut self) -> Option<Cow<'r, str>> { ... } fn by_ref<'r>(&'r mut self) -> ReplacerRef<'r, Self> { ... } }
Replacer describes types that can be used to replace matches in a string.
In general, users of this crate shouldn't need to implement this trait,
since implementations are already provided for &str
and
FnMut(&Captures) -> String
, which covers most use cases.
Required Methods
fn replace_append(&mut self, caps: &Captures, dst: &mut String)
Appends text to dst
to replace the current match.
The current match is represented by caps
, which is guaranteed to
have a match at capture group 0
.
For example, a no-op replacement would be
dst.extend(caps.get(0).unwrap().as_str())
.
Provided Methods
fn no_expansion<'r>(&'r mut self) -> Option<Cow<'r, str>>
Return a fixed unchanging replacement string.
When doing replacements, if access to Captures
is not needed (e.g.,
the replacement byte string does not need $
expansion), then it can
be beneficial to avoid finding sub-captures.
In general, this is called once for every call to replacen
.
fn by_ref<'r>(&'r mut self) -> ReplacerRef<'r, Self>
Return a Replacer
that borrows and wraps this Replacer
.
This is useful when you want to take a generic Replacer
(which might
not be cloneable) and use it without consuming it, so it can be used
more than once.
Example
use regex::{Regex, Replacer}; fn replace_all_twice<R: Replacer>( re: Regex, src: &str, mut rep: R, ) -> String { let dst = re.replace_all(src, rep.by_ref()); let dst = re.replace_all(&dst, rep.by_ref()); dst.into_owned() }
Implementations on Foreign Types
impl<'a> Replacer for &'a str
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impl<'a> Replacer for &'a str
fn replace_append(&mut self, caps: &Captures, dst: &mut String)
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fn replace_append(&mut self, caps: &Captures, dst: &mut String)
fn no_expansion(&mut self) -> Option<Cow<str>>
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fn no_expansion(&mut self) -> Option<Cow<str>>
fn by_ref<'r>(&'r mut self) -> ReplacerRef<'r, Self>
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fn by_ref<'r>(&'r mut self) -> ReplacerRef<'r, Self>