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</pre><pre class="rust"><code><span class="doccomment">//! Extension traits to provide parsing methods on foreign types.
</span><span class="kw">use </span><span class="kw">crate</span>::buffer::Cursor;
<span class="kw">use </span><span class="kw">crate</span>::parse::Peek;
<span class="kw">use </span><span class="kw">crate</span>::parse::{ParseStream, <span class="prelude-ty">Result</span>};
<span class="kw">use </span><span class="kw">crate</span>::sealed::lookahead;
<span class="kw">use </span><span class="kw">crate</span>::token::CustomToken;
<span class="kw">use </span>proc_macro2::Ident;
<span class="doccomment">/// Additional methods for `Ident` not provided by proc-macro2 or libproc_macro.
///
/// This trait is sealed and cannot be implemented for types outside of Syn. It
/// is implemented only for `proc_macro2::Ident`.
</span><span class="kw">pub trait </span>IdentExt: Sized + private::Sealed {
<span class="doccomment">/// Parses any identifier including keywords.
///
/// This is useful when parsing macro input which allows Rust keywords as
/// identifiers.
///
/// # Example
///
/// ```
/// use syn::{Error, Ident, Result, Token};
/// use syn::ext::IdentExt;
/// use syn::parse::ParseStream;
///
/// mod kw {
/// syn::custom_keyword!(name);
/// }
///
/// // Parses input that looks like `name = NAME` where `NAME` can be
/// // any identifier.
/// //
/// // Examples:
/// //
/// // name = anything
/// // name = impl
/// fn parse_dsl(input: ParseStream) -&gt; Result&lt;Ident&gt; {
/// input.parse::&lt;kw::name&gt;()?;
/// input.parse::&lt;Token![=]&gt;()?;
/// let name = input.call(Ident::parse_any)?;
/// Ok(name)
/// }
/// ```
</span><span class="kw">fn </span>parse_any(input: ParseStream) -&gt; <span class="prelude-ty">Result</span>&lt;<span class="self">Self</span>&gt;;
<span class="doccomment">/// Peeks any identifier including keywords. Usage:
/// `input.peek(Ident::peek_any)`
///
/// This is different from `input.peek(Ident)` which only returns true in
/// the case of an ident which is not a Rust keyword.
</span><span class="attribute">#[allow(non_upper_case_globals)]
</span><span class="kw">const </span>peek_any: private::PeekFn = private::PeekFn;
<span class="doccomment">/// Strips the raw marker `r#`, if any, from the beginning of an ident.
///
/// - unraw(`x`) = `x`
/// - unraw(`move`) = `move`
/// - unraw(`r#move`) = `move`
///
/// # Example
///
/// In the case of interop with other languages like Python that have a
/// different set of keywords than Rust, we might come across macro input
/// that involves raw identifiers to refer to ordinary variables in the
/// other language with a name that happens to be a Rust keyword.
///
/// The function below appends an identifier from the caller&#39;s input onto a
/// fixed prefix. Without using `unraw()`, this would tend to produce
/// invalid identifiers like `__pyo3_get_r#move`.
///
/// ```
/// use proc_macro2::Span;
/// use syn::Ident;
/// use syn::ext::IdentExt;
///
/// fn ident_for_getter(variable: &amp;Ident) -&gt; Ident {
/// let getter = format!(&quot;__pyo3_get_{}&quot;, variable.unraw());
/// Ident::new(&amp;getter, Span::call_site())
/// }
/// ```
</span><span class="kw">fn </span>unraw(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; Ident;
}
<span class="kw">impl </span>IdentExt <span class="kw">for </span>Ident {
<span class="kw">fn </span>parse_any(input: ParseStream) -&gt; <span class="prelude-ty">Result</span>&lt;<span class="self">Self</span>&gt; {
input.step(|cursor| <span class="kw">match </span>cursor.ident() {
<span class="prelude-val">Some</span>((ident, rest)) =&gt; <span class="prelude-val">Ok</span>((ident, rest)),
<span class="prelude-val">None </span>=&gt; <span class="prelude-val">Err</span>(cursor.error(<span class="string">&quot;expected ident&quot;</span>)),
})
}
<span class="kw">fn </span>unraw(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; Ident {
<span class="kw">let </span>string = <span class="self">self</span>.to_string();
<span class="kw">if let </span><span class="prelude-val">Some</span>(string) = string.strip_prefix(<span class="string">&quot;r#&quot;</span>) {
Ident::new(string, <span class="self">self</span>.span())
} <span class="kw">else </span>{
<span class="self">self</span>.clone()
}
}
}
<span class="kw">impl </span>Peek <span class="kw">for </span>private::PeekFn {
<span class="kw">type </span>Token = private::IdentAny;
}
<span class="kw">impl </span>CustomToken <span class="kw">for </span>private::IdentAny {
<span class="kw">fn </span>peek(cursor: Cursor) -&gt; bool {
cursor.ident().is_some()
}
<span class="kw">fn </span>display() -&gt; <span class="kw-2">&amp;</span><span class="lifetime">&#39;static </span>str {
<span class="string">&quot;identifier&quot;
</span>}
}
<span class="kw">impl </span>lookahead::Sealed <span class="kw">for </span>private::PeekFn {}
<span class="kw">mod </span>private {
<span class="kw">use </span>proc_macro2::Ident;
<span class="kw">pub trait </span>Sealed {}
<span class="kw">impl </span>Sealed <span class="kw">for </span>Ident {}
<span class="kw">pub struct </span>PeekFn;
<span class="kw">pub struct </span>IdentAny;
<span class="kw">impl </span>Copy <span class="kw">for </span>PeekFn {}
<span class="kw">impl </span>Clone <span class="kw">for </span>PeekFn {
<span class="kw">fn </span>clone(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; <span class="self">Self </span>{
<span class="kw-2">*</span><span class="self">self
</span>}
}
}
</code></pre></div>
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