Struct regex_automata::dfa::onepass::Builder
source · pub struct Builder { /* private fields */ }
Expand description
A builder for a one-pass DFA.
This builder permits configuring options for the syntax of a pattern, the NFA construction and the DFA construction. This builder is different from a general purpose regex builder in that it permits fine grain configuration of the construction process. The trade off for this is complexity, and the possibility of setting a configuration that might not make sense. For example, there are two different UTF-8 modes:
syntax::Config::utf8
controls whether the pattern itself can contain sub-expressions that match invalid UTF-8.thompson::Config::utf8
controls whether empty matches that split a Unicode codepoint are reported or not.
Generally speaking, callers will want to either enable all of these or disable all of these.
§Example
This example shows how to disable UTF-8 mode in the syntax and the NFA. This is generally what you want for matching on arbitrary bytes.
use regex_automata::{
dfa::onepass::DFA,
nfa::thompson,
util::syntax,
Match,
};
let re = DFA::builder()
.syntax(syntax::Config::new().utf8(false))
.thompson(thompson::Config::new().utf8(false))
.build(r"foo(?-u:[^b])ar.*")?;
let (mut cache, mut caps) = (re.create_cache(), re.create_captures());
let haystack = b"foo\xFFarzz\xE2\x98\xFF\n";
re.captures(&mut cache, haystack, &mut caps);
// Notice that `(?-u:[^b])` matches invalid UTF-8,
// but the subsequent `.*` does not! Disabling UTF-8
// on the syntax permits this.
//
// N.B. This example does not show the impact of
// disabling UTF-8 mode on a one-pass DFA Config,
// since that only impacts regexes that can
// produce matches of length 0.
assert_eq!(Some(Match::must(0, 0..8)), caps.get_match());
Implementations§
source§impl Builder
impl Builder
sourcepub fn build(&self, pattern: &str) -> Result<DFA, BuildError>
pub fn build(&self, pattern: &str) -> Result<DFA, BuildError>
Build a one-pass DFA from the given pattern.
If there was a problem parsing or compiling the pattern, then an error is returned.
sourcepub fn build_many<P: AsRef<str>>(
&self,
patterns: &[P],
) -> Result<DFA, BuildError>
pub fn build_many<P: AsRef<str>>( &self, patterns: &[P], ) -> Result<DFA, BuildError>
Build a one-pass DFA from the given patterns.
When matches are returned, the pattern ID corresponds to the index of the pattern in the slice given.
sourcepub fn build_from_nfa(&self, nfa: NFA) -> Result<DFA, BuildError>
pub fn build_from_nfa(&self, nfa: NFA) -> Result<DFA, BuildError>
Build a DFA from the given NFA.
§Example
This example shows how to build a DFA if you already have an NFA in hand.
use regex_automata::{dfa::onepass::DFA, nfa::thompson::NFA, Match};
// This shows how to set non-default options for building an NFA.
let nfa = NFA::compiler()
.configure(NFA::config().shrink(true))
.build(r"[a-z0-9]+")?;
let re = DFA::builder().build_from_nfa(nfa)?;
let (mut cache, mut caps) = (re.create_cache(), re.create_captures());
re.captures(&mut cache, "foo123bar", &mut caps);
assert_eq!(Some(Match::must(0, 0..9)), caps.get_match());
sourcepub fn configure(&mut self, config: Config) -> &mut Builder
pub fn configure(&mut self, config: Config) -> &mut Builder
Apply the given one-pass DFA configuration options to this builder.
sourcepub fn syntax(&mut self, config: Config) -> &mut Builder
pub fn syntax(&mut self, config: Config) -> &mut Builder
Set the syntax configuration for this builder using
syntax::Config
.
This permits setting things like case insensitivity, Unicode and multi line mode.
These settings only apply when constructing a one-pass DFA directly from a pattern.
sourcepub fn thompson(&mut self, config: Config) -> &mut Builder
pub fn thompson(&mut self, config: Config) -> &mut Builder
Set the Thompson NFA configuration for this builder using
nfa::thompson::Config
.
This permits setting things like whether additional time should be spent shrinking the size of the NFA.
These settings only apply when constructing a DFA directly from a pattern.
Trait Implementations§
Auto Trait Implementations§
impl !Freeze for Builder
impl !RefUnwindSafe for Builder
impl Send for Builder
impl !Sync for Builder
impl Unpin for Builder
impl UnwindSafe for Builder
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
source§impl<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
source§default unsafe fn clone_to_uninit(&self, dst: *mut T)
default unsafe fn clone_to_uninit(&self, dst: *mut T)
clone_to_uninit
)