virtue-next 0.1.3

A sinless derive macro helper
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
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142

use super::GenEnum;
use super::GenStruct;
use super::Impl;
use super::Parent;
use super::StreamBuilder;
use crate::Result;
use crate::parse::Visibility;
use crate::prelude::Delimiter;
use crate::prelude::Ident;
use crate::prelude::Span;

/// Builder for generating a module with its contents.
pub struct GenerateMod<'a, P: Parent> {
    parent: &'a mut P,
    name: Ident,
    uses: Vec<StreamBuilder>,
    vis: Visibility,
    content: StreamBuilder,
}

impl<'a, P: Parent> GenerateMod<'a, P> {
    pub(crate) fn new(
        parent: &'a mut P,
        name: impl Into<String>,
    ) -> Self {
        Self {
            parent,
            name: Ident::new(name.into().as_str(), Span::call_site()),
            uses: Vec::new(),
            vis: Visibility::Default,
            content: StreamBuilder::new(),
        }
    }

    /// Add a `use ...;` to the current mod
    ///
    /// `generator.impl_mod("foo").add_use("bar")` will generate:
    ///
    /// ```ignore
    /// mod foo {
    ///     use bar;
    /// }
    /// ```
    ///
    /// This is especially useful with `.add_use("super::*");`, which will pull all parent imports into scope
    ///
    /// # Errors
    ///
    /// Returns an error if parsing fails.
    pub fn add_use(
        &mut self,
        r#use: impl AsRef<str>,
    ) -> Result {
        let mut builder = StreamBuilder::new();
        builder.ident_str("use").push_parsed(r#use)?.punct(';');
        self.uses.push(builder);
        Ok(())
    }

    /// Generate a struct with the given name. See [`GenStruct`] for more info.
    pub fn generate_struct(
        &mut self,
        name: impl Into<String>,
    ) -> GenStruct<'_, Self> {
        GenStruct::new(self, name)
    }

    /// Generate an enum with the given name. See [`GenEnum`] for more info.
    pub fn generate_enum(
        &mut self,
        name: impl Into<String>,
    ) -> GenEnum<'_, Self> {
        GenEnum::new(self, name)
    }

    /// Generate an `impl <name>` implementation. See [`Impl`] for more information.
    pub fn r#impl(
        &mut self,
        name: impl Into<String>,
    ) -> Impl<'_, Self> {
        Impl::new(self, name)
    }

    /// Generate an `impl <name>` implementation. See [`Impl`] for more information.
    ///
    /// Alias for [`impl`] which doesn't need a `r#` prefix.
    ///
    /// [`impl`]: #method.impl
    ///
    /// # Panics
    ///
    /// Panics if an internal invariant is violated.
    pub fn generate_impl(
        &mut self,
        name: impl Into<String>,
    ) -> Impl<'_, Self> {
        Impl::new(self, name)
    }
}

impl<P: Parent> Drop for GenerateMod<'_, P> {
    fn drop(&mut self) {
        let mut builder = StreamBuilder::new();
        if self.vis == Visibility::Pub {
            builder.ident_str("pub");
        }
        builder
            .ident_str("mod")
            .ident(self.name.clone())
            .group(Delimiter::Brace, |group| {
                for r#use in std::mem::take(&mut self.uses) {
                    group.append(r#use);
                }
                group.append(std::mem::take(&mut self.content));
                Ok(())
            })
            .unwrap();

        self.parent.append(builder);
    }
}

impl<P: Parent> Parent for GenerateMod<'_, P> {
    fn append(
        &mut self,
        builder: StreamBuilder,
    ) {
        self.content.append(builder);
    }

    fn name(&self) -> &crate::prelude::Ident {
        &self.name
    }

    fn generics(&self) -> Option<&crate::parse::Generics> {
        None
    }

    fn generic_constraints(&self) -> Option<&crate::parse::GenericConstraints> {
        None
    }
}