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</pre><pre class="rust ">
<span class="doccomment">//! This module provides two utility macros for testing custom derives. They can</span>
<span class="doccomment">//! be used together to eliminate some of the boilerplate required in order to</span>
<span class="doccomment">//! declare and test custom derive implementations.</span>
<span class="comment">// XXX: Stop using `ignore` blocks for examples in this module.</span>
<span class="comment">// Re-exports used by the decl_derive! and test_derive!</span>
<span class="kw">pub</span> <span class="kw">mod</span> <span class="ident">syn</span> {
<span class="kw">pub</span> <span class="kw">use</span> <span class="ident">syn</span>::<span class="kw-2">*</span>; <span class="comment">// For syn::parse_derive_input</span>
}
<span class="kw">pub</span> <span class="kw">mod</span> <span class="ident">quote</span> {
<span class="kw">pub</span> <span class="kw">use</span> <span class="ident">quote</span>::<span class="kw-2">*</span>; <span class="comment">// For quote::Tokens</span>
}
<span class="kw">pub</span> <span class="kw">mod</span> <span class="ident">proc_macro</span> {
<span class="kw">pub</span> <span class="kw">use</span> <span class="ident">proc_macro</span>::<span class="kw-2">*</span>; <span class="comment">// For proc_macro::TokenStream</span>
}
<span class="doccomment">/// The `decl_derive!` macro declares a custom derive wrapper. It will parse the</span>
<span class="doccomment">/// incoming TokenStream into a `synstructure::Structure` object, and pass it</span>
<span class="doccomment">/// into the inner function.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Your inner function should have the following type:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// # extern crate quote;</span>
<span class="doccomment">/// # extern crate synstructure;</span>
<span class="doccomment">/// fn derive(input: synstructure::Structure) -> quote::Tokens {</span>
<span class="doccomment">/// // Your body here</span>
<span class="doccomment">/// # unimplemented!()</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Usage</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```ignore</span>
<span class="doccomment">/// fn derive_interesting(mut input: synstructure::Structure) -> quote::Tokens {</span>
<span class="doccomment">/// // Your body here</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// decl_derive!([Interesting, attributes(interesting_ignore)] => derive_interesting);</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">macro_export</span>]</span>
<span class="macro">macro_rules</span><span class="macro">!</span> <span class="ident">decl_derive</span> {
<span class="comment">// XXX: Switch to using this variant everywhere?</span>
([<span class="macro-nonterminal">$</span><span class="macro-nonterminal">derives</span>:<span class="ident">ident</span> $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">derive_t</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>] <span class="op">=></span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">inner</span>:<span class="ident">path</span>) <span class="op">=></span> {
<span class="attribute">#[<span class="ident">proc_macro_derive</span>(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">derives</span> $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">derive_t</span>)<span class="kw-2">*</span>)]</span>
<span class="attribute">#[<span class="ident">allow</span>(<span class="ident">non_snake_case</span>)]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">derives</span>(
<span class="ident">i</span>: <span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">macros</span>::<span class="ident">proc_macro</span>::<span class="ident">TokenStream</span>
) <span class="op">-></span> <span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">macros</span>::<span class="ident">proc_macro</span>::<span class="ident">TokenStream</span>
{
<span class="kw">let</span> <span class="ident">parsed</span> <span class="op">=</span> <span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">macros</span>::<span class="ident">syn</span>::<span class="ident">parse_derive_input</span>(<span class="kw-2">&</span><span class="ident">i</span>.<span class="ident">to_string</span>())
.<span class="ident">expect</span>(<span class="macro">concat</span><span class="macro">!</span>(<span class="string">"Failed to parse input to `#[derive("</span>,
<span class="macro">stringify</span><span class="macro">!</span>(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">derives</span>),
<span class="string">")]`"</span>));
<span class="macro-nonterminal">$</span><span class="macro-nonterminal">inner</span>(<span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">Structure</span>::<span class="ident">new</span>(<span class="kw-2">&</span><span class="ident">parsed</span>)).<span class="ident">parse</span>()
.<span class="ident">expect</span>(<span class="macro">concat</span><span class="macro">!</span>(<span class="string">"Failed to parse output from `#[derive("</span>,
<span class="macro">stringify</span><span class="macro">!</span>(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">derives</span>),
<span class="string">")]`"</span>))
}
};
}
<span class="doccomment">/// Run a test on a custom derive. This macro expands both the original struct</span>
<span class="doccomment">/// and the expansion to ensure that they compile correctly, and confirms that</span>
<span class="doccomment">/// feeding the original struct into the named derive will produce the written</span>
<span class="doccomment">/// output.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// You can add `no_build` to the end of the macro invocation to disable</span>
<span class="doccomment">/// checking that the written code compiles. This is useful in contexts where</span>
<span class="doccomment">/// the procedural macro cannot depend on the crate where it is used during</span>
<span class="doccomment">/// tests.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Usage</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```ignore</span>
<span class="doccomment">/// test_derive!{</span>
<span class="doccomment">/// super::derive_interesting {</span>
<span class="doccomment">/// struct A {</span>
<span class="doccomment">/// a: i32,</span>
<span class="doccomment">/// b: i32,</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// expands to {</span>
<span class="doccomment">/// impl ::Interesting for A {</span>
<span class="doccomment">/// fn is_interesting(&self) -> bool {</span>
<span class="doccomment">/// match *self {</span>
<span class="doccomment">/// A { a: ref __binding_0, b: ref __binding_1, } => {</span>
<span class="doccomment">/// false ||</span>
<span class="doccomment">/// ::Interesting::is_interesting(__binding_0) ||</span>
<span class="doccomment">/// ::Interesting::is_interesting(__binding_1)</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">macro_export</span>]</span>
<span class="macro">macro_rules</span><span class="macro">!</span> <span class="ident">test_derive</span> {
(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">name</span>:<span class="ident">path</span> { $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">i</span>:<span class="ident">tt</span>)<span class="op">*</span> } <span class="ident">expands</span> <span class="ident">to</span> { $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">o</span>:<span class="ident">tt</span>)<span class="op">*</span> }) <span class="op">=></span> {
{
<span class="attribute">#[<span class="ident">allow</span>(<span class="ident">dead_code</span>)]</span>
<span class="kw">fn</span> <span class="ident">ensure_compiles</span>() {
$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">i</span>)<span class="op">*</span>
$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">o</span>)<span class="op">*</span>
}
<span class="macro">test_derive</span><span class="macro">!</span>(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">name</span> { $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">i</span>)<span class="op">*</span> } <span class="ident">expands</span> <span class="ident">to</span> { $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">o</span>)<span class="op">*</span> } <span class="ident">no_build</span>);
}
};
(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">name</span>:<span class="ident">path</span> { $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">i</span>:<span class="ident">tt</span>)<span class="op">*</span> } <span class="ident">expands</span> <span class="ident">to</span> { $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">o</span>:<span class="ident">tt</span>)<span class="op">*</span> } <span class="ident">no_build</span>) <span class="op">=></span> {
{
<span class="kw">let</span> <span class="ident">i</span> <span class="op">=</span> <span class="macro">stringify</span><span class="macro">!</span>( $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">i</span>)<span class="op">*</span> );
<span class="kw">let</span> <span class="ident">parsed</span> <span class="op">=</span> <span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">macros</span>::<span class="ident">syn</span>::<span class="ident">parse_derive_input</span>(<span class="ident">i</span>)
.<span class="ident">expect</span>(<span class="macro">concat</span><span class="macro">!</span>(<span class="string">"Failed to parse input to `#[derive("</span>,
<span class="macro">stringify</span><span class="macro">!</span>(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">name</span>),
<span class="string">")]`"</span>));
<span class="comment">// NOTE: These outputs can get quite long, so we'd like to avoid</span>
<span class="comment">// recursive macros like `quote!` for parsing them. Instead, we use</span>
<span class="comment">// stringify (which is inconsistent with whitespace), split on</span>
<span class="comment">// whitespace, and compare the lists of tokens.</span>
<span class="kw">let</span> <span class="ident">res</span> <span class="op">=</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">name</span>(<span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">Structure</span>::<span class="ident">new</span>(<span class="kw-2">&</span><span class="ident">parsed</span>));
<span class="kw">let</span> <span class="ident">expected</span> <span class="op">=</span> <span class="macro">stringify</span><span class="macro">!</span>( $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">o</span>)<span class="op">*</span> );
<span class="kw">let</span> <span class="ident">res_toks</span> <span class="op">=</span> <span class="ident">res</span>.<span class="ident">as_str</span>()
.<span class="ident">split</span>(<span class="op">|</span><span class="ident">ch</span>: <span class="ident">char</span><span class="op">|</span> <span class="ident">ch</span>.<span class="ident">is_whitespace</span>())
.<span class="ident">filter</span>(<span class="op">|</span><span class="ident">s</span>: <span class="op">&&</span><span class="ident">str</span><span class="op">|</span> <span class="op">!</span><span class="ident">s</span>.<span class="ident">is_empty</span>())
.<span class="ident">collect</span>::<span class="op"><</span><span class="ident">Vec</span><span class="op"><</span><span class="kw-2">&</span><span class="ident">str</span><span class="op">>></span>();
<span class="kw">let</span> <span class="ident">exp_toks</span> <span class="op">=</span> <span class="ident">expected</span>
.<span class="ident">split</span>(<span class="op">|</span><span class="ident">ch</span>: <span class="ident">char</span><span class="op">|</span> <span class="ident">ch</span>.<span class="ident">is_whitespace</span>())
.<span class="ident">filter</span>(<span class="op">|</span><span class="ident">s</span>: <span class="op">&&</span><span class="ident">str</span><span class="op">|</span> <span class="op">!</span><span class="ident">s</span>.<span class="ident">is_empty</span>())
.<span class="ident">collect</span>::<span class="op"><</span><span class="ident">Vec</span><span class="op"><</span><span class="kw-2">&</span><span class="ident">str</span><span class="op">>></span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(
<span class="ident">res_toks</span>,
<span class="ident">exp_toks</span>
)
}
};
}
<span class="doccomment">/// A helper macro for declaring relatively straightforward derive</span>
<span class="doccomment">/// implementations. It provides mechanisms for operating over structures</span>
<span class="doccomment">/// performing modifications on each field etc.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This macro is a helper wrapper over decl_derive!.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Warning</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This is an unstable experimental macro API, which may be changed or removed</span>
<span class="doccomment">/// in a future version. I'm not yet confident enough that this API is useful</span>
<span class="doccomment">/// enough to warrant its complexity and inclusion in synstructure.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Note</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This feature is implemented behind the `simple-derive` feature, and is only</span>
<span class="doccomment">/// avaliable when that feature is enabled.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Example</span>
<span class="doccomment">/// ```ignore</span>
<span class="doccomment">/// simple_derive! {</span>
<span class="doccomment">/// // This macro implements the `Interesting` method exported by the `aa`</span>
<span class="doccomment">/// // crate. It will explicitly add an `extern crate` invocation to import the</span>
<span class="doccomment">/// // crate into the expanded context.</span>
<span class="doccomment">/// derive(Interesting) impl ::aa::Interesting {</span>
<span class="doccomment">/// // A "filter" block can be added. It evaluates its body with the (s)</span>
<span class="doccomment">/// // variable bound to a mutable reference to the input `Structure`</span>
<span class="doccomment">/// // object.</span>
<span class="doccomment">/// //</span>
<span class="doccomment">/// // This block can be used to perform general transformations, such as</span>
<span class="doccomment">/// // filtering out fields which should be ignored by all methods and for</span>
<span class="doccomment">/// // the purposes of binding type parameters.</span>
<span class="doccomment">/// filter(s) {</span>
<span class="doccomment">/// s.filter(|bi| bi.ast().ident != Some("a".into()));</span>
<span class="doccomment">/// }</span>
<span class="doccomment">///</span>
<span class="doccomment">/// // This is an implementation of a method in the implemented crate. The</span>
<span class="doccomment">/// // return value should be the series of match patterns to destructure</span>
<span class="doccomment">/// // the `self` argument with.</span>
<span class="doccomment">/// fn is_interesting(&self as s) -> bool {</span>
<span class="doccomment">/// s.fold(false, |acc, bi| {</span>
<span class="doccomment">/// quote!(#acc || ::aa::Interesting::is_interesting(#bi))</span>
<span class="doccomment">/// })</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"simple-derive"</span>)]</span>
<span class="attribute">#[<span class="ident">macro_export</span>]</span>
<span class="macro">macro_rules</span><span class="macro">!</span> <span class="ident">simple_derive</span> {
<span class="comment">// entry point</span>
(
<span class="ident">derive</span>(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">name</span>:<span class="ident">ident</span>) <span class="macro-nonterminal">$</span><span class="macro-nonterminal">iname</span>:<span class="ident">ident</span> <span class="kw">impl</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">path</span>:<span class="ident">path</span> { $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">rest</span>:<span class="ident">tt</span>)<span class="op">*</span> }
) <span class="op">=></span> {
<span class="macro">simple_derive</span><span class="macro">!</span>(@<span class="ident">I</span> [<span class="macro-nonterminal">$</span><span class="macro-nonterminal">name</span>, <span class="macro-nonterminal">$</span><span class="macro-nonterminal">iname</span>, <span class="macro-nonterminal">$</span><span class="macro-nonterminal">path</span>] { $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">rest</span>)<span class="op">*</span> } [] []);
};
<span class="comment">// Adding a filter block</span>
(
@<span class="ident">I</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">opt</span>:<span class="ident">tt</span> {
<span class="ident">filter</span>(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">s</span>:<span class="ident">ident</span>) {
$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">body</span>:<span class="ident">tt</span>)<span class="op">*</span>
}
$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">rest</span>:<span class="ident">tt</span>)<span class="op">*</span>
} [$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">done</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>] [$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">filter</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>]
) <span class="op">=></span> {
<span class="macro">simple_derive</span><span class="macro">!</span>(
@<span class="ident">I</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">opt</span> { $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">rest</span>)<span class="op">*</span> } [$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">done</span>)<span class="kw-2">*</span>] [
$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">filter</span>)<span class="op">*</span>
[
<span class="ident">st_name</span> <span class="op">=</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">s</span>,
<span class="ident">body</span> <span class="op">=</span> {
$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">body</span>)<span class="op">*</span>
},
]
]
);
};
<span class="comment">// &self bound method</span>
(
@<span class="ident">I</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">opt</span>:<span class="ident">tt</span> {
<span class="kw">fn</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">fn_name</span>:<span class="ident">ident</span> (<span class="kw-2">&</span><span class="self">self</span> <span class="kw">as</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">s</span>:<span class="ident">ident</span> $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">params</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) $(<span class="op">-></span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">t</span>:<span class="ident">ty</span>)<span class="op">*</span> {
$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">body</span>:<span class="ident">tt</span>)<span class="op">*</span>
}
$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">rest</span>:<span class="ident">tt</span>)<span class="op">*</span>
} [$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">done</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>] [$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">filter</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>]
) <span class="op">=></span> {
<span class="macro">simple_derive</span><span class="macro">!</span>(
@<span class="ident">I</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">opt</span> { $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">rest</span>)<span class="op">*</span> } [
$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">done</span>)<span class="op">*</span>
[
<span class="ident">st_name</span> <span class="op">=</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">s</span>,
<span class="ident">bind_style</span> <span class="op">=</span> <span class="ident">Ref</span>,
<span class="ident">body</span> <span class="op">=</span> { $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">body</span>)<span class="op">*</span> },
<span class="ident">result</span> <span class="op">=</span> <span class="ident">result</span>,
<span class="ident">expanded</span> <span class="op">=</span> {
<span class="kw">fn</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">fn_name</span>(<span class="kw-2">&</span><span class="self">self</span> $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">params</span>)<span class="kw-2">*</span>) $(<span class="op">-></span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">t</span>)<span class="op">*</span> {
<span class="kw">match</span> <span class="kw-2">*</span><span class="self">self</span> { #<span class="ident">result</span> }
}
},
]
] [$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">filter</span>)<span class="kw-2">*</span>]
);
};
<span class="comment">// &mut self bound method</span>
(
@<span class="ident">I</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">opt</span>:<span class="ident">tt</span> {
<span class="kw">fn</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">fn_name</span>:<span class="ident">ident</span> (<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span> <span class="kw">as</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">s</span>:<span class="ident">ident</span> $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">params</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) $(<span class="op">-></span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">t</span>:<span class="ident">ty</span>)<span class="op">*</span> {
$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">body</span>:<span class="ident">tt</span>)<span class="op">*</span>
}
$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">rest</span>:<span class="ident">tt</span>)<span class="op">*</span>
} [$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">done</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>] [$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">filter</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>]
) <span class="op">=></span> {
<span class="macro">simple_derive</span><span class="macro">!</span>(
@<span class="ident">I</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">opt</span> { $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">rest</span>)<span class="op">*</span> } [
$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">done</span>)<span class="op">*</span>
[
<span class="ident">st_name</span> <span class="op">=</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">s</span>,
<span class="ident">bind_style</span> <span class="op">=</span> <span class="ident">RefMut</span>,
<span class="ident">body</span> <span class="op">=</span> { $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">body</span>)<span class="op">*</span> },
<span class="ident">result</span> <span class="op">=</span> <span class="ident">result</span>,
<span class="ident">expanded</span> <span class="op">=</span> {
<span class="kw">fn</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">fn_name</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span> $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">params</span>)<span class="kw-2">*</span>) $(<span class="op">-></span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">t</span>)<span class="op">*</span> {
<span class="kw">match</span> <span class="kw-2">*</span><span class="self">self</span> { #<span class="ident">result</span> }
}
},
]
] [$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">filter</span>)<span class="kw-2">*</span>]
);
};
<span class="comment">// self bound method</span>
(
@<span class="ident">I</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">opt</span>:<span class="ident">tt</span> {
<span class="kw">fn</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">fn_name</span>:<span class="ident">ident</span> (<span class="self">self</span> <span class="kw">as</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">s</span>:<span class="ident">ident</span> $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">params</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) $(<span class="op">-></span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">t</span>:<span class="ident">ty</span>)<span class="op">*</span> {
$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">body</span>:<span class="ident">tt</span>)<span class="op">*</span>
}
$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">rest</span>:<span class="ident">tt</span>)<span class="op">*</span>
} [$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">done</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>] [$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">filter</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>]
) <span class="op">=></span> {
<span class="macro">simple_derive</span><span class="macro">!</span>(
@<span class="ident">I</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">opt</span> { $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">rest</span>)<span class="op">*</span> } [
$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">done</span>)<span class="op">*</span>
[
<span class="ident">st_name</span> <span class="op">=</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">s</span>,
<span class="ident">bind_style</span> <span class="op">=</span> <span class="ident">Move</span>,
<span class="ident">body</span> <span class="op">=</span> { $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">body</span>)<span class="op">*</span> },
<span class="ident">result</span> <span class="op">=</span> <span class="ident">result</span>,
<span class="ident">expanded</span> <span class="op">=</span> {
<span class="kw">fn</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">fn_name</span>(<span class="self">self</span> $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">params</span>)<span class="kw-2">*</span>) $(<span class="op">-></span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">t</span>)<span class="op">*</span> {
<span class="kw">match</span> <span class="self">self</span> { #<span class="ident">result</span> }
}
},
]
] [$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">filter</span>)<span class="kw-2">*</span>]
);
};
<span class="comment">// XXX: Static methods?</span>
<span class="comment">// codegen after data collection</span>
(
@<span class="ident">I</span> [<span class="macro-nonterminal">$</span><span class="macro-nonterminal">name</span>:<span class="ident">ident</span>, <span class="macro-nonterminal">$</span><span class="macro-nonterminal">iname</span>:<span class="ident">ident</span>, <span class="macro-nonterminal">$</span><span class="macro-nonterminal">path</span>:<span class="ident">path</span>] {} [$(
[
<span class="ident">st_name</span> <span class="op">=</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">st_name</span>:<span class="ident">ident</span>,
<span class="ident">bind_style</span> <span class="op">=</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">bind_style</span>:<span class="ident">ident</span>,
<span class="ident">body</span> <span class="op">=</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">body</span>:<span class="ident">tt</span>,
<span class="ident">result</span> <span class="op">=</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">result</span>:<span class="ident">ident</span>,
<span class="ident">expanded</span> <span class="op">=</span> { $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">expanded</span>:<span class="ident">tt</span>)<span class="op">*</span> },
]
)<span class="kw-2">*</span>] [$(
[
<span class="ident">st_name</span> <span class="op">=</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">filter_st_name</span>:<span class="ident">ident</span>,
<span class="ident">body</span> <span class="op">=</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">filter_body</span>:<span class="ident">tt</span>,
]
)<span class="kw-2">*</span>]
) <span class="op">=></span> {
<span class="macro">decl_derive</span><span class="macro">!</span>([<span class="macro-nonterminal">$</span><span class="macro-nonterminal">name</span>] <span class="op">=></span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">iname</span>);
<span class="kw">fn</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">iname</span>(<span class="kw-2">mut</span> <span class="ident">st</span>: <span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">Structure</span>) <span class="op">-></span> <span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">macros</span>::<span class="ident">quote</span>::<span class="ident">Tokens</span> {
<span class="kw">let</span> _ <span class="op">=</span> <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">st</span>; <span class="comment">// Silence the unused mut warning</span>
<span class="comment">// Filter/transform the `Structure` object before cloning it for</span>
<span class="comment">// individual methods.</span>
$(
{
<span class="kw">let</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">filter_st_name</span> <span class="op">=</span> <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">st</span>;
<span class="macro-nonterminal">$</span><span class="macro-nonterminal">filter_body</span>
}
)<span class="op">*</span>
<span class="comment">// Clone the `Structure` object and set the correct binding style,</span>
<span class="comment">// then perform method specific expansion.</span>
$(
<span class="kw">let</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">result</span> <span class="op">=</span> {
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">st_name</span> <span class="op">=</span> <span class="ident">st</span>.<span class="ident">clone</span>();
<span class="macro-nonterminal">$</span><span class="macro-nonterminal">st_name</span>.<span class="ident">bind_with</span>(<span class="op">|</span>_<span class="op">|</span> ::<span class="ident">synstructure</span>::<span class="ident">BindStyle</span>::<span class="macro-nonterminal">$</span><span class="macro-nonterminal">bind_style</span>);
<span class="kw">let</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">result</span> <span class="op">=</span> {
<span class="macro-nonterminal">$</span><span class="macro-nonterminal">body</span>
};
<span class="macro">quote</span><span class="macro">!</span>{ $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">expanded</span>)<span class="op">*</span> }
};
)<span class="op">*</span>
<span class="ident">st</span>.<span class="ident">bound_impl</span>(<span class="macro">stringify</span><span class="macro">!</span>(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">path</span>), <span class="macro">quote</span><span class="macro">!</span>{
$(#<span class="macro-nonterminal">$</span><span class="macro-nonterminal">result</span>)<span class="op">*</span>
})
}
}
}
</pre>
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