proc_macro_roids 0.8.0

Traits and functions to make writing proc macros more ergonomic.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94

use quote::format_ident;
use syn::Ident;

/// Convenience methods on `Ident`s.
pub trait IdentExt {
    /// Returns a new `Ident` by appending this Ident and the specified suffix.
    ///
    /// # Parameters
    ///
    /// * `suffix`: Suffix to append.
    fn append<S>(&self, suffix: S) -> Ident
    where
        S: quote::IdentFragment;

    /// Returns a new `Ident` by prepending this Ident with the specified
    /// prefix.
    ///
    /// # Parameters
    ///
    /// * `prefix`: Prefix to prepend.
    fn prepend<S>(&self, prefix: S) -> Ident
    where
        S: quote::IdentFragment;
}

impl IdentExt for Ident {
    fn append<S>(&self, suffix: S) -> Ident
    where
        S: quote::IdentFragment,
    {
        format_ident!("{}{}", self, suffix)
    }

    fn prepend<S>(&self, suffix: S) -> Ident
    where
        S: quote::IdentFragment,
    {
        format_ident!("{}{}", suffix, self)
    }
}

#[cfg(test)]
mod tests {
    use proc_macro2::Span;
    use syn::Ident;

    use super::IdentExt;

    #[test]
    fn append_str_returns_appended_ident() {
        let one = Ident::new("One", Span::call_site());

        assert_eq!(Ident::new("OneTwo", Span::call_site()), one.append("Two"));
    }

    #[test]
    fn append_ident_returns_appended_ident() {
        let one = Ident::new("One", Span::call_site());
        let two = Ident::new("Two", Span::call_site());

        assert_eq!(Ident::new("OneTwo", Span::call_site()), one.append(two));
    }

    #[test]
    fn append_ident_ref_returns_appended_ident() {
        let one = Ident::new("One", Span::call_site());
        let two = Ident::new("Two", Span::call_site());

        assert_eq!(Ident::new("OneTwo", Span::call_site()), one.append(two));
    }

    #[test]
    fn prepend_str_returns_prepended_ident() {
        let one = Ident::new("One", Span::call_site());

        assert_eq!(Ident::new("TwoOne", Span::call_site()), one.prepend("Two"));
    }

    #[test]
    fn prepend_ident_returns_prepended_ident() {
        let one = Ident::new("One", Span::call_site());
        let two = Ident::new("Two", Span::call_site());

        assert_eq!(Ident::new("TwoOne", Span::call_site()), one.prepend(two));
    }

    #[test]
    fn prepend_ident_ref_returns_prepended_ident() {
        let one = Ident::new("One", Span::call_site());
        let two = Ident::new("Two", Span::call_site());

        assert_eq!(Ident::new("TwoOne", Span::call_site()), one.prepend(two));
    }
}