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
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
use super::{GenerateMod, Impl, ImplFor, StreamBuilder};
use crate::parse::{GenericConstraints, Generics};
use crate::prelude::{Ident, TokenStream};
#[must_use]
/// The generator is used to generate code.
///
/// Often you will want to use [`impl_for`] to generate an `impl <trait_name> for <target_name()>`.
///
/// [`impl_for`]: #method.impl_for
pub struct Generator {
pub(crate) name: Ident,
pub(crate) generics: Option<Generics>,
pub(crate) generic_constraints: Option<GenericConstraints>,
pub(crate) stream: StreamBuilder,
}
impl Generator {
pub(crate) fn new(
name: Ident,
generics: Option<Generics>,
generic_constraints: Option<GenericConstraints>,
) -> Self {
Self {
name,
generics,
generic_constraints,
stream: StreamBuilder::new(),
}
}
/// Return the name for the struct or enum that this is going to be implemented on.
pub fn target_name(&self) -> Ident {
self.name.clone()
}
/// Generate an `impl <target_name>` implementation. See [`Impl`] for more information.
pub fn r#impl(&mut self) -> Impl<Self> {
Impl::with_parent_name(self)
}
/// Generate an `impl <target_name>` implementation. See [`Impl`] for more information.
///
/// Alias for [`impl`] which doesn't need a `r#` prefix.
///
/// [`impl`]: #method.impl
pub fn generate_impl(&mut self) -> Impl<Self> {
Impl::with_parent_name(self)
}
/// Generate an `for <trait_name> for <target_name>` implementation. See [ImplFor] for more information.
pub fn impl_for(&mut self, trait_name: impl Into<String>) -> ImplFor<Self> {
ImplFor::new(self, trait_name)
}
/// Generate an `for <..lifetimes> <trait_name> for <target_name>` implementation. See [ImplFor] for more information.
///
/// Note:
/// - Lifetimes should _not_ have the leading apostrophe.
/// - The lifetimes passed to this function will automatically depend on any other lifetime this struct or enum may have. Example:
/// - The struct is `struct Foo<'a> {}`
/// - You call `generator.impl_for_with_lifetime("Bar", &["b"])
/// - The code will be `impl<'a, 'b: 'a> Bar<'b> for Foo<'a> {}`
/// - `trait_name` should _not_ have custom lifetimes. These will be added automatically.
///
/// ```no_run
/// # use virtue::prelude::*;
/// # let mut generator: Generator = unsafe { std::mem::zeroed() };
/// generator.impl_for_with_lifetimes("Foo", ["a", "b"]);
///
/// // will output:
/// // impl<'a, 'b> Foo<'a, 'b> for StructOrEnum { }
/// ```
pub fn impl_for_with_lifetimes<ITER, I, T>(
&mut self,
trait_name: T,
lifetimes: ITER,
) -> ImplFor<Self>
where
ITER: IntoIterator<Item = I>,
I: Into<String>,
T: Into<String>,
{
ImplFor::new_with_lifetimes(self, trait_name, lifetimes)
}
/// Generate a `mod <name> { ... }`. See [`GenerateMod`] for more info.
pub fn generate_mod(&mut self, mod_name: impl Into<String>) -> GenerateMod<Self> {
GenerateMod::new(self, mod_name)
}
/// Export the current stream to a file, making it very easy to debug the output of a derive macro.
/// This will try to find rust's `target` directory, and write `target/generated/<crate_name>/<name>_<file_postfix>.rs`.
///
/// Will return `true` if the file is written, `false` otherwise.
///
/// The outputted file is unformatted. Use `cargo fmt -- target/generated/<crate_name>/<file>.rs` to format the file.
pub fn export_to_file(&self, crate_name: &str, file_postfix: &str) -> bool {
use std::io::Write;
if let Ok(var) = std::env::var("CARGO_MANIFEST_DIR") {
let mut path = std::path::PathBuf::from(var);
loop {
{
let mut path = path.clone();
path.push("target");
if path.exists() {
path.push("generated");
path.push(crate_name);
if std::fs::create_dir_all(&path).is_err() {
return false;
}
path.push(format!("{}_{}.rs", self.target_name(), file_postfix));
if let Ok(mut file) = std::fs::File::create(path) {
let _ = file.write_all(self.stream.stream.to_string().as_bytes());
return true;
}
}
}
if let Some(parent) = path.parent() {
path = parent.to_owned();
} else {
break;
}
}
}
false
}
/// Consume the contents of this generator. This *must* be called, or else the generator will panic on drop.
pub fn finish(mut self) -> crate::prelude::Result<TokenStream> {
Ok(std::mem::take(&mut self.stream).stream)
}
}
impl Drop for Generator {
fn drop(&mut self) {
if !self.stream.stream.is_empty() && !std::thread::panicking() {
eprintln!("WARNING: Generator dropped but the stream is not empty. Please call `.finish()` on the generator");
}
}
}
impl super::Parent for Generator {
fn append(&mut self, builder: StreamBuilder) {
self.stream.append(builder);
}
fn name(&self) -> &Ident {
&self.name
}
fn generics(&self) -> Option<&Generics> {
self.generics.as_ref()
}
fn generic_constraints(&self) -> Option<&GenericConstraints> {
self.generic_constraints.as_ref()
}
}