wgsl_parse/
tokrepr.rs

1//! Turn an instance into a `TokenStream` that represents the instance.
2
3use tokrepr::TokRepr;
4use tokrepr::proc_macro2::TokenStream;
5use tokrepr::quote::{format_ident, quote};
6
7use crate::{SyntaxNode, span::Spanned, syntax::*};
8
9/// named nodes are those that have an identifier. We use this trait to conditionally
10/// implement TokRepr for Spanned<NamedNode>, which allows code injection in `quote_*!`
11/// macros from the `wesl` crate.
12trait NamedNode {
13    fn name(&self) -> Option<String>;
14}
15
16impl NamedNode for GlobalDeclaration {
17    fn name(&self) -> Option<String> {
18        self.ident().map(|id| id.to_string())
19    }
20}
21
22impl NamedNode for StructMember {
23    fn name(&self) -> Option<String> {
24        Some(self.ident.to_string())
25    }
26}
27
28impl NamedNode for Attribute {
29    fn name(&self) -> Option<String> {
30        if let Attribute::Custom(attr) = self {
31            Some(attr.name.to_string())
32        } else {
33            None
34        }
35    }
36}
37
38impl NamedNode for Expression {
39    fn name(&self) -> Option<String> {
40        if let Expression::TypeOrIdentifier(ty) = self {
41            Some(ty.ident.to_string())
42        } else {
43            None
44        }
45    }
46}
47
48impl NamedNode for Statement {
49    fn name(&self) -> Option<String> {
50        // COMBAK: this nesting is hell. Hopefully if-let chains will stabilize soon.
51        if let Statement::Compound(stmt) = self {
52            if stmt.statements.is_empty() {
53                if let [attr] = stmt.attributes.as_slice() {
54                    if let Attribute::Custom(attr) = attr.node() {
55                        return Some(attr.name.to_string());
56                    }
57                }
58            }
59        }
60        None
61    }
62}
63
64impl<T: NamedNode + TokRepr> TokRepr for Spanned<T> {
65    fn tok_repr(&self) -> TokenStream {
66        let node = self.node().tok_repr();
67        let span = self.span().tok_repr();
68
69        if let Some(name) = self.name() {
70            if let Some(suffix) = name.strip_prefix("#") {
71                let ident = format_ident!("{}", suffix);
72
73                return quote! {
74                    Spanned::new(#ident.to_owned().into(), #span)
75                };
76            }
77        }
78
79        quote! {
80            Spanned::new(#node, #span)
81        }
82    }
83}
84
85impl TokRepr for Ident {
86    fn tok_repr(&self) -> TokenStream {
87        let name = self.name();
88        if let Some(name) = name.strip_prefix("#") {
89            let ident = format_ident!("{}", name);
90            quote! {
91                Ident::from(#ident.to_owned())
92            }
93        } else {
94            let name = name.as_str();
95            quote! {
96                Ident::new(#name.to_string())
97            }
98        }
99    }
100}
wgsl_parse/tokrepr.rs

wgsl_parse/
tokrepr.rs
