async_codegen/rust/
syntax.rs

1/*
2 * Copyright © 2025 Anand Beh
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17use super::*;
18use crate::common::{SeparatedSeqAccept, Str};
19use crate::context::ContextProvides;
20use crate::{Output, SequenceAccept, Writable, WritableSeq};
21
22impl<O, Type> Writable<O> for UseType<Type> where O: Output, Type: Writable<O> {
23    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
24        output.write("use ").await?;
25        self.0.write_to(output).await?;
26        output.write(";\n").await
27    }
28}
29
30impl<O, Cond, Attr> Writable<O> for CfgAttr<Cond, Attr>
31where
32    O: Output,
33    Cond: Writable<O>,
34    Attr: Writable<O>,
35{
36    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
37        output.write("cfg_attr(").await?;
38        self.0.write_to(output).await?;
39        output.write(", ").await?;
40        self.1.write_to(output).await?;
41        output.write(")").await
42    }
43}
44
45impl<O, Cond> Writable<O> for Cfg<Cond>
46where
47    O: Output,
48    Cond: Writable<O>,
49{
50    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
51        output.write("cfg(").await?;
52        self.0.write_to(output).await?;
53        output.write(")").await
54    }
55}
56
57impl<O, Value> Writable<O> for Target<Value>
58where
59    O: Output,
60    Value: Writable<O>,
61{
62    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
63        let (kind, value) = match self {
64            Self::Os(value) => ("os", value),
65            Self::Family(value) => ("family", value),
66            Self::Arch(value) => ("arch", value),
67        };
68        output.write("target_").await?;
69        output.write(kind).await?;
70        output.write(" = \"").await?;
71        value.write_to(output).await?;
72        output.write("\"").await
73    }
74}
75
76impl<O, Arg> Writable<O> for Link<Arg>
77where
78    O: Output,
79    Arg: Writable<O>,
80{
81    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
82        output.write("link(").await?;
83        self.0.write_to(output).await?;
84        output.write(")").await
85    }
86}
87
88impl<O> Writable<O> for NoMangle
89where
90    O: Output,
91    O::Ctx: ContextProvides<Edition>,
92{
93    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
94        let edition = output.get_ctx();
95        output
96            .write(if edition >= &Edition::Rust2024 {
97                "unsafe(no_mangle)"
98            } else {
99                "no_mangle"
100            })
101            .await
102    }
103}
104
105impl<O, Lints> Writable<O> for AllowLints<Lints>
106where
107    O: Output,
108    Lints: WritableSeq<O>,
109{
110    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
111        let mut acceptor = SeparatedSeqAccept::new(output, Str("allow("), Str(","));
112        self.0.for_each(&mut acceptor).await?;
113        if acceptor.wrote_any {
114            output.write(")").await?;
115        }
116        Ok(())
117    }
118}
119
120impl<O, Msg, Since> Writable<O> for Deprecated<Msg, Since>
121where
122    O: Output,
123    Msg: Writable<O>,
124    Since: Writable<O>,
125{
126    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
127        match self {
128            Self::Basic => output.write("deprecated").await,
129            Self::Message(msg) => {
130                output.write("deprecated = \"").await?;
131                msg.write_to(output).await?;
132                output.write("\"").await
133            }
134            Self::Full { since, note } => {
135                output.write("deprecated(since = \"").await?;
136                since.write_to(output).await?;
137                output.write("\", note = \"").await?;
138                note.write_to(output).await?;
139                output.write("\")").await
140            }
141        }
142    }
143}
144
145impl<O> Writable<O> for MustUse
146where
147    O: Output,
148{
149    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
150        output.write("must_use").await
151    }
152}
153
154impl<O> Writable<O> for ModPub
155where
156    O: Output,
157{
158    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
159        output.write("pub").await
160    }
161}
162
163impl<O, Abi> Writable<O> for ModUnsafeExtern<Abi>
164where
165    O: Output,
166    Abi: Writable<O>,
167{
168    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
169        output.write("unsafe extern \"").await?;
170        self.0.write_to(output).await?;
171        output.write("\"").await
172    }
173}
174
175impl<O, Abi, Body> Writable<O> for ExternBlock<Abi, Body>
176where
177    O: Output,
178    O::Ctx: ContextProvides<Edition>,
179    Abi: Writable<O>,
180    Body: Writable<O>,
181{
182    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
183        let edition = output.get_ctx();
184        if edition >= &Edition::Rust2024 {
185            output.write("unsafe ").await?;
186        }
187        output.write("extern \"").await?;
188        self.abi.write_to(output).await?;
189        output.write("\" {").await?;
190        self.body.write_to(output).await?;
191        output.write("}").await
192    }
193}
194
195impl<O: Output, Expr> Writable<O> for UnsafeBlock<Expr>
196where
197    Expr: Writable<O>,
198{
199    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
200        o.write("unsafe {\n").await?;
201        self.0.write_to(o).await?;
202        o.write("\n}").await?;
203        Ok(())
204    }
205}
206
207impl<O, InputVars, Expr> Writable<O> for Closure<InputVars, Expr>
208where
209    O: Output,
210    InputVars: WritableSeq<O>,
211    Expr: Writable<O>,
212{
213    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
214        o.write("|").await?;
215        self.input_vars
216            .for_each(&mut SeparatedSeqAccept::comma_separated(o))
217            .await?;
218        o.write("| {\n").await?;
219        self.inside_block.write_to(o).await?;
220        o.write("\n}").await?;
221        Ok(())
222    }
223}
224
225impl<O: Output, Recv, FuncName, Args> Writable<O> for FunctionCall<Recv, FuncName, Args>
226where
227    Recv: Writable<O>,
228    FuncName: Writable<O>,
229    Args: WritableSeq<O>,
230{
231    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
232        self.receiver.write_to(o).await?;
233        o.write(if self.is_assoc { "::" } else { "." }).await?;
234        self.name.write_to(o).await?;
235        AnonTuple(&self.args).write_to(o).await
236    }
237}
238
239impl<O: Output, Name, Args> Writable<O> for Turbofish<Name, Args> where Name: Writable<O>, Args: WritableSeq<O> {
240    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
241        self.0.write_to(output).await?;
242        let mut acceptor = SeparatedSeqAccept::new(output, Str("::<"), Str(", "));
243        self.1.for_each(&mut acceptor).await?;
244        if acceptor.wrote_any {
245            output.write(">").await?;
246        }
247        Ok(())
248    }
249}
250
251impl<O: Output, Variable, Expr> Writable<O> for LetStmt<Variable, Expr>
252where
253    Variable: Writable<O>,
254    Expr: Writable<O>,
255{
256    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
257        o.write("let ").await?;
258        AssignStmt(&self.0, &self.1).write_to(o).await
259    }
260}
261
262impl<O: Output, Variable, Expr> Writable<O> for AssignStmt<Variable, Expr> where Variable: Writable<O>, Expr: Writable<O> {
263    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
264        self.0.write_to(o).await?;
265        o.write(" = ").await?;
266        self.1.write_to(o).await?;
267        o.write(";\n").await?;
268        Ok(())
269    }
270}
271
272impl<O: Output, Cont, Item> Writable<O> for AssociatedItem<Cont, Item>
273where
274    Cont: Writable<O>,
275    Item: Writable<O>,
276{
277    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
278        self.0.write_to(o).await?;
279        o.write("::").await?;
280        self.1.write_to(o).await
281    }
282}
283
284impl<O: Output, Expr> Writable<O> for QuestionMarkAfter<Expr>
285where
286    Expr: Writable<O>,
287{
288    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
289        self.0.write_to(o).await?;
290        o.write("?").await?;
291        Ok(())
292    }
293}
294
295impl<O: Output, Expr> Writable<O> for OkResultOf<Expr>
296where
297    Expr: Writable<O>,
298{
299    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
300        o.write("Ok(").await?;
301        self.0.write_to(o).await?;
302        o.write(")").await?;
303        Ok(())
304    }
305}
306
307impl<O: Output, Type, Trait> Writable<O> for TypeAsTrait<Type, Trait>
308where
309    Type: Writable<O>,
310    Trait: Writable<O>,
311{
312    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
313        o.write("<").await?;
314        self.0.write_to(o).await?;
315        o.write(" as ").await?;
316        self.1.write_to(o).await?;
317        o.write(">").await?;
318        Ok(())
319    }
320}
321
322impl<O, Mods, Name, Args, Return, Where, Body> Writable<O>
323    for FunctionDef<Mods, Name, Args, Return, Where, Body>
324where
325    O: Output,
326    Mods: WritableSeq<O>,
327    Name: Writable<O>,
328    Args: WritableSeq<O>,
329    Return: Writable<O>,
330    Where: WritableSeq<O>,
331    Body: Writable<O>,
332{
333    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
334        self.mods.for_each(&mut ModsAccept(o)).await?;
335        o.write("fn ").await?;
336        self.name.write_to(o).await?;
337        AnonTuple(&self.args).write_to(o).await?;
338        o.write(" -> ").await?;
339        self.return_type.write_to(o).await?;
340        self.where_conds.for_each(&mut where_cond_accept(o)).await?;
341        self.body.write_to(o).await?;
342        o.write("\n").await?;
343        Ok(())
344    }
345}
346
347impl<O: Output> Writable<O> for FunctionBodyDeclare {
348    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
349        output.write(";").await
350    }
351}
352
353impl<O: Output, Inner> Writable<O> for FunctionBodyImplement<Inner>
354where
355    Inner: Writable<O>,
356{
357    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
358        output.write("{\n").await?;
359        self.0.write_to(output).await?;
360        output.write("\n}").await
361    }
362}
363
364impl<O, Args, Return> Writable<O> for FunctionPtr<Args, Return>
365where
366    O: Output,
367    Args: WritableSeq<O>,
368    Return: Writable<O>,
369{
370    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
371        let kind = match self.kind {
372            FunctionPtrKind::FnPtr => "fn",
373            FunctionPtrKind::Fn => "Fn",
374            FunctionPtrKind::FnMut => "FnMut",
375            FunctionPtrKind::FnOnce => "FnOnce",
376        };
377        output.write(kind).await?;
378        AnonTuple(&self.args).write_to(output).await?;
379        output.write(" -> ").await?;
380        self.return_type.write_to(output).await
381    }
382}
383
384impl<O: Output, Type, Value> Writable<O> for AssociatedTypeEquals<Type, Value>
385where
386    Type: Writable<O>,
387    Value: Writable<O>,
388{
389    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
390        self.0.write_to(o).await?;
391        o.write("=").await?;
392        self.1.write_to(o).await
393    }
394}
395
396impl<O: Output, Type> Writable<O> for DynOf<Type>
397where
398    Type: Writable<O>,
399{
400    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
401        o.write("dyn ").await?;
402        self.0.write_to(o).await
403    }
404}
405
406impl<O: Output, Type> Writable<O> for RefOf<Type>
407where
408    Type: Writable<O>,
409{
410    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
411        o.write("&").await?;
412        self.0.write_to(o).await
413    }
414}
415
416impl<O: Output, Type> Writable<O> for ImplOf<Type>
417where
418    Type: Writable<O>,
419{
420    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
421        o.write("impl ").await?;
422        self.0.write_to(o).await
423    }
424}
425
426impl<O: Output, Type> Writable<O> for LifetimedRefOf<'_, Type>
427where
428    Type: Writable<O>,
429{
430    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
431        o.write("&'").await?;
432        o.write(self.0).await?;
433        o.write(" ").await?;
434        self.1.write_to(o).await
435    }
436}
437
438impl<O: Output, VarName, Value> Writable<O> for AssociatedTypeDef<VarName, Value>
439where
440    VarName: Writable<O>,
441    Value: Writable<O>,
442{
443    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
444        o.write("\ntype ").await?;
445        self.0.write_to(o).await?;
446        o.write(" = ").await?;
447        self.1.write_to(o).await?;
448        o.write(";\n").await?;
449        Ok(())
450    }
451}
452
453impl<O, Mods, Name, TypeVars, SuperTraits, Body> Writable<O>
454    for TraitDef<Mods, Name, TypeVars, SuperTraits, Body>
455where
456    O: Output,
457    Mods: WritableSeq<O>,
458    Name: Writable<O>,
459    TypeVars: WritableSeq<O>,
460    SuperTraits: WritableSeq<O>,
461    Body: Writable<O>,
462{
463    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
464        self.mods.for_each(&mut ModsAccept(o)).await?;
465        o.write("trait ").await?;
466        self.name.write_to(o).await?;
467        TypeArgAccept::new(o)
468            .write_inside_diamond(&self.type_variables)
469            .await?;
470        self.super_traits
471            .for_each(&mut type_arg_bound_accept(o))
472            .await?;
473        o.write(" {").await?;
474        self.body.write_to(o).await?;
475        o.write("}").await?;
476        Ok(())
477    }
478}
479
480impl<O, TypeVars, Trait, Recv, Where, Body> Writable<O>
481    for TraitImpl<TypeVars, Trait, Recv, Where, Body>
482where
483    O: Output,
484    TypeVars: WritableSeq<O>,
485    Trait: Writable<O>,
486    Recv: Writable<O>,
487    Where: WritableSeq<O>,
488    Body: Writable<O>,
489{
490    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
491        o.write("impl").await?;
492        TypeArgAccept::new(o)
493            .write_inside_diamond(&self.type_variables)
494            .await?;
495        o.write(" ").await?;
496        self.the_trait.write_to(o).await?;
497        o.write(" for ").await?;
498        self.receiver.write_to(o).await?;
499        self.where_conds.for_each(&mut where_cond_accept(o)).await?;
500        o.write(" {").await?;
501        self.body.write_to(o).await?;
502        o.write("}").await?;
503        Ok(())
504    }
505}
506
507impl<O, Mods, Name, Elements> Writable<O> for StructDef<Mods, Name, Elements>
508where
509    O: Output,
510    Mods: WritableSeq<O>,
511    Name: Writable<O>,
512    Elements: WritableSeq<O>,
513{
514    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
515        self.mods.for_each(&mut ModsAccept(o)).await?;
516        o.write("struct ").await?;
517        match &self.kind {
518            StructKind::Tuple(name, elements) => {
519                NamedTuple {
520                    name,
521                    args: elements,
522                }
523                .write_to(o)
524                .await?;
525                o.write(";").await
526            }
527            StructKind::NamedFields(name, elements) => {
528                StructCall {
529                    name,
530                    body: StructFields(elements),
531                }
532                .write_to(o)
533                .await
534            }
535        }
536    }
537}
538
539impl<O, Name, Body> Writable<O> for StructCall<Name, Body>
540where
541    O: Output,
542    Name: Writable<O>,
543    Body: Writable<O>,
544{
545    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
546        self.name.write_to(o).await?;
547        o.write(" { ").await?;
548        self.body.write_to(o).await?;
549        o.write(" }").await
550    }
551}
552
553impl<O, Fields> Writable<O> for StructFields<Fields>
554where
555    O: Output,
556    Fields: WritableSeq<O>,
557{
558    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
559        self.0.for_each(&mut struct_fields_accept(output)).await
560    }
561}
562
563impl<O, Name, Value> Writable<O> for DeclareField<Name, Value>
564where
565    O: Output,
566    Name: Writable<O>,
567    Value: Writable<O>,
568{
569    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
570        FunctionParam(&self.0, &self.1).write_to(o).await
571    }
572}
573
574impl<O, Name, Args> Writable<O> for NamedTuple<Name, Args>
575where
576    O: Output,
577    Name: Writable<O>,
578    Args: WritableSeq<O>,
579{
580    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
581        self.name.write_to(output).await?;
582        // Only write the parentheses if arguments is non-empty
583        let mut separator = SeparatedSeqAccept::new(output, Str("("), Str(", "));
584        self.args.for_each(&mut separator).await?;
585        if separator.wrote_any {
586            output.write(")").await?;
587        }
588        Ok(())
589    }
590}
591
592impl<O, Args> Writable<O> for AnonTuple<Args>
593where
594    O: Output,
595    Args: WritableSeq<O>,
596{
597    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
598        o.write("(").await?;
599        self.0
600            .for_each(&mut SeparatedSeqAccept::comma_separated(o))
601            .await?;
602        o.write(")").await
603    }
604}
605
606impl<O, Attr, Value> Writable<O> for WithAttributes<Attr, Value>
607where
608    O: Output,
609    Attr: WritableSeq<O>,
610    Value: Writable<O>,
611{
612    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
613        self.attr
614            .for_each(&mut AttributesAccept::with_separator(
615                output,
616                self.separator,
617            ))
618            .await?;
619        self.value.write_to(output).await
620    }
621}
622
623impl<O, Mods, Name, Entries> Writable<O> for EnumDef<Mods, Name, Entries>
624where
625    O: Output,
626    Mods: WritableSeq<O>,
627    Name: Writable<O>,
628    Entries: WritableSeq<O>,
629{
630    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
631        self.mods.for_each(&mut ModsAccept(output)).await?;
632        output.write("enum ").await?;
633        self.name.write_to(output).await?;
634        output.write(" {").await?;
635        self.entries
636            .for_each(&mut SeparatedSeqAccept::comma_separated(output))
637            .await?;
638        output.write("}").await
639    }
640}
641
642impl<O, Name, TypeArgs> Writable<O> for Parameterized<Name, TypeArgs>
643where
644    O: Output,
645    Name: Writable<O>,
646    TypeArgs: WritableSeq<O>,
647{
648    async fn write_to(&self, o: &mut O) -> Result<(), O::Error> {
649        self.name.write_to(o).await?;
650        TypeArgAccept::new(o)
651            .write_inside_diamond(&self.type_args)
652            .await
653    }
654}
655
656impl<O, TypeVar, Bounds> Writable<O> for BoundedTypeVar<TypeVar, Bounds>
657where
658    O: Output,
659    TypeVar: Writable<O>,
660    Bounds: WritableSeq<O>,
661{
662    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
663        self.0.write_to(output).await?;
664        self.1.for_each(&mut type_arg_bound_accept(output)).await
665    }
666}
667
668impl<O> Writable<O> for Lifetime<'_>
669where
670    O: Output,
671{
672    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
673        output.write("'").await?;
674        output.write(self.0).await
675    }
676}
677
678impl<O, Name, Type> Writable<O> for FunctionParam<Name, Type>
679where
680    O: Output,
681    Name: Writable<O>,
682    Type: Writable<O>,
683{
684    async fn write_to(&self, output: &mut O) -> Result<(), O::Error> {
685        self.0.write_to(output).await?;
686        output.write(": ").await?;
687        self.1.write_to(output).await
688    }
689}
690
691//
692// Sequence acceptors
693//
694
695struct ModsAccept<'o, O>(&'o mut O);
696
697impl<'o, O: Output> SequenceAccept<O> for ModsAccept<'o, O> {
698    async fn accept<W>(&mut self, writable: &W) -> Result<(), O::Error>
699    where
700        W: Writable<O>,
701    {
702        writable.write_to(&mut self.0).await?;
703        self.0.write(" ").await
704    }
705}
706
707struct TypeArgAccept<'o, O> {
708    inner: SeparatedSeqAccept<'o, O, Str<&'static str>, Str<&'static str>>,
709}
710
711impl<'o, O> TypeArgAccept<'o, O> {
712    fn new(output: &'o mut O) -> Self {
713        Self {
714            inner: SeparatedSeqAccept::new(output, Str("<"), Str(", ")),
715        }
716    }
717}
718
719impl<'o, O> TypeArgAccept<'o, O>
720where
721    O: Output,
722{
723    async fn write_inside_diamond<TypeArgs>(&mut self, type_args: &TypeArgs) -> Result<(), O::Error>
724    where
725        TypeArgs: WritableSeq<O>,
726    {
727        type_args.for_each(&mut self.inner).await?;
728        if self.inner.wrote_any {
729            self.inner.output.write(">").await?;
730        }
731        Ok(())
732    }
733}
734
735fn type_arg_bound_accept<'o, O>(
736    output: &'o mut O,
737) -> SeparatedSeqAccept<'o, O, Str<&'static str>, Str<&'static str>> {
738    SeparatedSeqAccept::new(output, Str(": "), Str(" + "))
739}
740
741fn struct_fields_accept<'o, O>(
742    output: &'o mut O,
743) -> SeparatedSeqAccept<'o, O, Str<&'static str>, Str<&'static str>> {
744    SeparatedSeqAccept::new(output, Str("\n"), Str(",\n"))
745}
746
747fn where_cond_accept<'o, O>(
748    output: &'o mut O,
749) -> SeparatedSeqAccept<'o, O, Str<&'static str>, Str<&'static str>> {
750    SeparatedSeqAccept::new(output, Str(" where "), Str(", "))
751}
async_codegen/rust/syntax.rs

async_codegen/rust/
syntax.rs
