<p>The builder permits configuring two different aspects of a <code>Regex</code>:</p>
<ul>
<li><ahref="struct.Builder.html#method.configure"title="method regex_automata::meta::Builder::configure"><code>Builder::configure</code></a> will set high-level configuration options as
described by a <ahref="struct.Config.html"title="struct regex_automata::meta::Config"><code>Config</code></a>.</li>
<li><ahref="struct.Builder.html#method.syntax"title="method regex_automata::meta::Builder::syntax"><code>Builder::syntax</code></a> will set the syntax level configuration options
as described by a <ahref="../util/syntax/struct.Config.html"title="struct regex_automata::util::syntax::Config"><code>util::syntax::Config</code></a>.
This only applies when building a <code>Regex</code> from pattern strings.</li>
</ul>
<p>Once configured, the builder can then be used to construct a <code>Regex</code> from
one of 4 different inputs:</p>
<ul>
<li><ahref="struct.Builder.html#method.build"title="method regex_automata::meta::Builder::build"><code>Builder::build</code></a> creates a regex from a single pattern string.</li>
<li><ahref="struct.Builder.html#method.build_many"title="method regex_automata::meta::Builder::build_many"><code>Builder::build_many</code></a> creates a regex from many pattern strings.</li>
<li><ahref="struct.Builder.html#method.build_from_hir"title="method regex_automata::meta::Builder::build_from_hir"><code>Builder::build_from_hir</code></a> creates a regex from a
<li><ahref="struct.Builder.html#method.build_many_from_hir"title="method regex_automata::meta::Builder::build_many_from_hir"><code>Builder::build_many_from_hir</code></a> creates a regex from many
<p>The latter two methods in particular provide a way to construct a fully
feature regular expression matcher directly from an <code>Hir</code> expression
without having to first convert it to a string. (This is in contrast to the
top-level <code>regex</code> crate which intentionally provides no such API in order
to avoid making <code>regex-syntax</code> a public dependency.)</p>
<p>As a convenience, this builder may be created via <ahref="struct.Regex.html#method.builder"title="associated function regex_automata::meta::Regex::builder"><code>Regex::builder</code></a>, which
<h2id="example-change-the-line-terminator"><aclass="doc-anchor"href="#example-change-the-line-terminator">§</a>Example: change the line terminator</h2>
</div></details><h2id="implementations"class="section-header">Implementations<ahref="#implementations"class="anchor">§</a></h2><divid="implementations-list"><detailsclass="toggle implementors-toggle"open><summary><sectionid="impl-Builder"class="impl"><aclass="src rightside"href="../../src/regex_automata/meta/regex.rs.html#3329-3634">source</a><ahref="#impl-Builder"class="anchor">§</a><h3class="code-header">impl <aclass="struct"href="struct.Builder.html"title="struct regex_automata::meta::Builder">Builder</a></h3></section></summary><divclass="impl-items"><detailsclass="toggle method-toggle"open><summary><sectionid="method.new"class="method"><aclass="src rightside"href="../../src/regex_automata/meta/regex.rs.html#3331-3337">source</a><h4class="code-header">pub fn <ahref="#method.new"class="fn">new</a>() -><aclass="struct"href="struct.Builder.html"title="struct regex_automata::meta::Builder">Builder</a></h4></section></summary><divclass="docblock"><p>Creates a new builder for configuring and constructing a <ahref="struct.Regex.html"title="struct regex_automata::meta::Regex"><code>Regex</code></a>.</p>
</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.build"class="method"><aclass="src rightside"href="../../src/regex_automata/meta/regex.rs.html#3359-3361">source</a><h4class="code-header">pub fn <ahref="#method.build"class="fn">build</a>(&self, pattern: &<aclass="primitive"href="https://doc.rust-lang.org/1.80.0/std/primitive.str.html">str</a>) -><aclass="enum"href="https://doc.rust-lang.org/1.80.0/core/result/enum.Result.html"title="enum core::result::Result">Result</a><<aclass="struct"href="struct.Regex.html"title="struct regex_automata::meta::Regex">Regex</a>, <aclass="struct"href="struct.BuildError.html"title="struct regex_automata::meta::BuildError">BuildError</a>></h4></section></summary><divclass="docblock"><p>Builds a <code>Regex</code> from a single pattern string.</p>
) -><aclass="enum"href="https://doc.rust-lang.org/1.80.0/core/result/enum.Result.html"title="enum core::result::Result">Result</a><<aclass="struct"href="struct.Regex.html"title="struct regex_automata::meta::Regex">Regex</a>, <aclass="struct"href="struct.BuildError.html"title="struct regex_automata::meta::BuildError">BuildError</a>></h4></section></summary><divclass="docblock"><p>Builds a <code>Regex</code> from many pattern strings.</p>
<h5id="example-finding-the-pattern-that-caused-an-error"><aclass="doc-anchor"href="#example-finding-the-pattern-that-caused-an-error">§</a>Example: finding the pattern that caused an error</h5>
<p>This is useful if you needed to parse a pattern string into an <code>Hir</code>
for other reasons (such as analysis or transformations). This routine
permits building a <code>Regex</code> directly from the <code>Hir</code> expression instead
of first converting the <code>Hir</code> back to a pattern string.</p>
<p>When using this method, any options set via <ahref="struct.Builder.html#method.syntax"title="method regex_automata::meta::Builder::syntax"><code>Builder::syntax</code></a> are
ignored. Namely, the syntax options only apply when parsing a pattern
string, which isn’t relevant here.</p>
<p>If there was a problem building the underlying regex matcher for the
given <code>Hir</code>, then an error is returned.</p>
) -><aclass="enum"href="https://doc.rust-lang.org/1.80.0/core/result/enum.Result.html"title="enum core::result::Result">Result</a><<aclass="struct"href="struct.Regex.html"title="struct regex_automata::meta::Regex">Regex</a>, <aclass="struct"href="struct.BuildError.html"title="struct regex_automata::meta::BuildError">BuildError</a>></h4></section></summary><divclass="docblock"><p>Builds a <code>Regex</code> directly from many <code>Hir</code> expressions.</p>
<p>This is useful if you needed to parse pattern strings into <code>Hir</code>
expressions for other reasons (such as analysis or transformations).
This routine permits building a <code>Regex</code> directly from the <code>Hir</code>
expressions instead of first converting the <code>Hir</code> expressions back to
pattern strings.</p>
<p>When using this method, any options set via <ahref="struct.Builder.html#method.syntax"title="method regex_automata::meta::Builder::syntax"><code>Builder::syntax</code></a> are
ignored. Namely, the syntax options only apply when parsing a pattern
string, which isn’t relevant here.</p>
<p>If there was a problem building the underlying regex matcher for the
given <code>Hir</code> expressions, then an error is returned.</p>
<p>Note that unlike <ahref="struct.Builder.html#method.build_many"title="method regex_automata::meta::Builder::build_many"><code>Builder::build_many</code></a>, this can only fail as a
result of building the underlying matcher. In that case, there is
no single <code>Hir</code> expression that can be isolated as a reason for the
failure. So if this routine fails, it’s not possible to determine which
<code>Hir</code> expression caused the failure.</p>
</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.syntax"class="method"><aclass="src rightside"href="../../src/regex_automata/meta/regex.rs.html#3626-3633">source</a><h4class="code-header">pub fn <ahref="#method.syntax"class="fn">syntax</a>(&mut self, config: <aclass="struct"href="../util/syntax/struct.Config.html"title="struct regex_automata::util::syntax::Config">Config</a>) ->&mut <aclass="struct"href="struct.Builder.html"title="struct regex_automata::meta::Builder">Builder</a></h4></section></summary><divclass="docblock"><p>Configure the syntax options when parsing a pattern string while
building a <code>Regex</code>.</p>
<p>These options <em>only</em> apply when <ahref="struct.Builder.html#method.build"title="method regex_automata::meta::Builder::build"><code>Builder::build</code></a> or <ahref="struct.Builder.html#method.build_many"title="method regex_automata::meta::Builder::build_many"><code>Builder::build_many</code></a>
are used. The other build methods accept <code>Hir</code> values, which have
<code><ahref="https://doc.rust-lang.org/1.80.0/core/convert/trait.From.html"title="trait core::convert::From">From</a><T> for U</code> chooses to do.</p>
</div></details></div></details><detailsclass="toggle implementors-toggle"><summary><sectionid="impl-ToOwned-for-T"class="impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.80.0/src/alloc/borrow.rs.html#83-85">source</a><ahref="#impl-ToOwned-for-T"class="anchor">§</a><h3class="code-header">impl<T><aclass="trait"href="https://doc.rust-lang.org/1.80.0/alloc/borrow/trait.ToOwned.html"title="trait alloc::borrow::ToOwned">ToOwned</a> for T<divclass="where">where
T: <aclass="trait"href="https://doc.rust-lang.org/1.80.0/core/clone/trait.Clone.html"title="trait core::clone::Clone">Clone</a>,</div></h3></section></summary><divclass="impl-items"><detailsclass="toggle"open><summary><sectionid="associatedtype.Owned"class="associatedtype trait-impl"><ahref="#associatedtype.Owned"class="anchor">§</a><h4class="code-header">type <ahref="https://doc.rust-lang.org/1.80.0/alloc/borrow/trait.ToOwned.html#associatedtype.Owned"class="associatedtype">Owned</a> = T</h4></section></summary><divclass='docblock'>The resulting type after obtaining ownership.</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.to_owned"class="method trait-impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.80.0/src/alloc/borrow.rs.html#88">source</a><ahref="#method.to_owned"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.80.0/alloc/borrow/trait.ToOwned.html#tymethod.to_owned"class="fn">to_owned</a>(&self) -> T</h4></section></summary><divclass='docblock'>Creates owned data from borrowed data, usually by cloning. <ahref="https://doc.rust-lang.org/1.80.0/alloc/borrow/trait.ToOwned.html#tymethod.to_owned">Read more</a></div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.clone_into"class="method trait-impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.80.0/src/alloc/borrow.rs.html#92">source</a><ahref="#method.clone_into"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.80.0/alloc/borrow/trait.ToOwned.html#method.clone_into"class="fn">clone_into</a>(&self, target: <aclass="primitive"href="https://doc.rust-lang.org/1.80.0/std/primitive.reference.html">&mut T</a>)</h4></section></summary><divclass='docblock'>Uses borrowed data to replace owned data, usually by cloning. <ahref="https://doc.rust-lang.org/1.80.0/alloc/borrow/trait.ToOwned.html#method.clone_into">Read more</a></div></details></div></details><detailsclass="toggle implementors-toggle"><summary><sectionid="impl-TryFrom%3CU%3E-for-T"class="impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.80.0/src/core/convert/mod.rs.html#805-807">source</a><ahref="#impl-TryFrom%3CU%3E-for-T"class="anchor">§</a><h3class="code-header">impl<T, U><aclass="trait"href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><U> for T<divclass="where">where
U: <aclass="trait"href="https://doc.rust-lang.org/1.80.0/core/convert/trait.Into.html"title="trait core::convert::Into">Into</a><T>,</div></h3></section></summary><divclass="impl-items"><detailsclass="toggle"open><summary><sectionid="associatedtype.Error"class="associatedtype trait-impl"><ahref="#associatedtype.Error"class="anchor">§</a><h4class="code-header">type <ahref="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html#associatedtype.Error"class="associatedtype">Error</a> = <aclass="enum"href="https://doc.rust-lang.org/1.80.0/core/convert/enum.Infallible.html"title="enum core::convert::Infallible">Infallible</a></h4></section></summary><divclass='docblock'>The type returned in the event of a conversion error.</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.try_from"class="method trait-impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.80.0/src/core/convert/mod.rs.html#812">source</a><ahref="#method.try_from"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html#tymethod.try_from"class="fn">try_from</a>(value: U) -><aclass="enum"href="https://doc.rust-lang.org/1.80.0/core/result/enum.Result.html"title="enum core::result::Result">Result</a><T, <T as <aclass="trait"href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><U>>::<aclass="associatedtype"href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html#associatedtype.Error"title="type core::convert::TryFrom::Error">Error</a>></h4></section></summary><divclass='docblock'>Performs the conversion.</div></details></div></details><detailsclass="toggle implementors-toggle"><summary><sectionid="impl-TryInto%3CU%3E-for-T"class="impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.80.0/src/core/convert/mod.rs.html#790-792">source</a><ahref="#impl-TryInto%3CU%3E-for-T"class="anchor">§</a><h3class="code-header">impl<T, U><aclass="trait"href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryInto.html"title="trait core::convert::TryInto">TryInto</a><U> for T<divclass="where">where
U: <aclass="trait"href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><T>,</div></h3></section></summary><divclass="impl-items"><detailsclass="toggle"open><summary><sectionid="associatedtype.Error-1"class="associatedtype trait-impl"><ahref="#associatedtype.Error-1"class="anchor">§</a><h4class="code-header">type <ahref="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryInto.html#associatedtype.Error"class="associatedtype">Error</a> = <U as <aclass="trait"href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><T>>::<aclass="associatedtype"href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html#associatedtype.Error"title="type core::convert::TryFrom::Error">Error</a></h4></section></summary><divclass='docblock'>The type returned in the event of a conversion error.</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.try_into"class="method trait-impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.80.0/src/core/convert/mod.rs.html#797">source</a><ahref="#method.try_into"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryInto.html#tymethod.try_into"class="fn">try_into</a>(self) -><aclass="enum"href="https://doc.rust-lang.org/1.80.0/core/result/enum.Result.html"title="enum core::result::Result">Result</a><U, <U as <aclass="trait"href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><T>>::<aclass="associatedtype"href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html#associatedtype.Error"title="type core::convert::TryFrom::Error">Error</a>></h4></section></summary><divclass='docblock'>Performs the conversion.</div></details></div></details></div></section></div></main></body></html>