cxx_gen/syntax/
namespace.rs

1use crate::syntax::qualified::QualifiedName;
2use quote::IdentFragment;
3use std::fmt::{self, Display};
4use std::slice::Iter;
5use syn::parse::{Error, Parse, ParseStream, Result};
6use syn::{Expr, Ident, Lit, Meta, Token};
7
8mod kw {
9    syn::custom_keyword!(namespace);
10}
11
12#[derive(Clone, Default)]
13pub(crate) struct Namespace {
14    segments: Vec<Ident>,
15}
16
17impl Namespace {
18    pub(crate) const ROOT: Self = Namespace {
19        segments: Vec::new(),
20    };
21
22    pub(crate) fn iter(&self) -> Iter<Ident> {
23        self.segments.iter()
24    }
25
26    pub(crate) fn parse_bridge_attr_namespace(input: ParseStream) -> Result<Self> {
27        if input.is_empty() {
28            return Ok(Namespace::ROOT);
29        }
30
31        input.parse::<kw::namespace>()?;
32        input.parse::<Token![=]>()?;
33        let namespace = input.parse::<Namespace>()?;
34        input.parse::<Option<Token![,]>>()?;
35        Ok(namespace)
36    }
37
38    pub(crate) fn parse_meta(meta: &Meta) -> Result<Self> {
39        if let Meta::NameValue(meta) = meta {
40            match &meta.value {
41                Expr::Lit(expr) => {
42                    if let Lit::Str(lit) = &expr.lit {
43                        let segments = QualifiedName::parse_quoted(lit)?.segments;
44                        return Ok(Namespace { segments });
45                    }
46                }
47                Expr::Path(expr)
48                    if expr.qself.is_none()
49                        && expr
50                            .path
51                            .segments
52                            .iter()
53                            .all(|segment| segment.arguments.is_none()) =>
54                {
55                    let segments = expr
56                        .path
57                        .segments
58                        .iter()
59                        .map(|segment| segment.ident.clone())
60                        .collect();
61                    return Ok(Namespace { segments });
62                }
63                _ => {}
64            }
65        }
66        Err(Error::new_spanned(meta, "unsupported namespace attribute"))
67    }
68}
69
70impl Default for &Namespace {
71    fn default() -> Self {
72        const ROOT: &Namespace = &Namespace::ROOT;
73        ROOT
74    }
75}
76
77impl Parse for Namespace {
78    fn parse(input: ParseStream) -> Result<Self> {
79        let segments = QualifiedName::parse_quoted_or_unquoted(input)?.segments;
80        Ok(Namespace { segments })
81    }
82}
83
84impl Display for Namespace {
85    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
86        for segment in self {
87            write!(f, "{}$", segment)?;
88        }
89        Ok(())
90    }
91}
92
93impl IdentFragment for Namespace {
94    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
95        Display::fmt(self, f)
96    }
97}
98
99impl<'a> IntoIterator for &'a Namespace {
100    type Item = &'a Ident;
101    type IntoIter = Iter<'a, Ident>;
102    fn into_iter(self) -> Self::IntoIter {
103        self.iter()
104    }
105}
106
107impl<'a> FromIterator<&'a Ident> for Namespace {
108    fn from_iter<I>(idents: I) -> Self
109    where
110        I: IntoIterator<Item = &'a Ident>,
111    {
112        let segments = idents.into_iter().cloned().collect();
113        Namespace { segments }
114    }
115}
cxx_gen/syntax/namespace.rs

cxx_gen/syntax/
namespace.rs
