tamasfe_macro_utils/
path.rs

1use syn::{Path, PathArguments, Type};
2
3#[macro_export]
4macro_rules! path_segments {
5    ($($ty:tt)::*) => {
6        $crate::path::PathSegments::new(&[$(stringify!($ty)),*])
7    };
8    (::$($ty:tt)::*) => {
9        $crate::path::PathSegments::new(&[$(stringify!($ty)),*])
10    };
11}
12
13#[derive(Debug, Clone)]
14pub struct PathSegments<'s>(&'s [&'s str]);
15
16impl<'s> PathSegments<'s> {
17    pub fn new(segments: &'s [&'s str]) -> Self {
18        Self(segments)
19    }
20}
21
22pub fn is_type(ty: &Type, segments: &PathSegments) -> bool {
23    match ty {
24        Type::Path(p) => is_path(&p.path, segments),
25        Type::Reference(ty_ref) => {
26            match &*ty_ref.elem {
27                Type::Path(p) => is_path(&p.path, segments),
28                _ => false, // FIXME: Nested references are not supported
29            }
30        }
31        _ => false,
32    }
33}
34
35pub fn is_path(p: &Path, segments: &PathSegments) -> bool {
36    if segments.0.len() < p.segments.len() {
37        return false;
38    }
39
40    let mut ty_segs = p.segments.iter().rev();
41
42    for seg in segments.0.iter().rev() {
43        match ty_segs.next() {
44            Some(ty_seg) => {
45                if ty_seg.ident != seg {
46                    return false;
47                }
48            }
49            None => return true,
50        }
51    }
52
53    true
54}
55
56pub fn type_args(ty: &Type) -> Option<&PathArguments> {
57    match ty {
58        Type::Path(p) => p.path.segments.last().map(|s| &s.arguments),
59        Type::Reference(ty_ref) => match &*ty_ref.elem {
60            Type::Path(p) => p.path.segments.last().map(|s| &s.arguments),
61            _ => None,
62        },
63        _ => None,
64    }
65}
66
67pub fn is_option(ty: &Type) -> bool {
68    is_type(ty, &path_segments!(::core::option::Option))
69        || is_type(ty, &path_segments!(::std::option::Option))
70}
tamasfe_macro_utils/path.rs

tamasfe_macro_utils/
path.rs
