dbg_pls/
debug_struct.rs

1use crate::{DebugPls, Formatter};
2
3/// A helper designed to assist with creation of
4/// [`DebugPls`] implementations for structs.
5///
6/// # Examples
7///
8/// ```rust
9/// use dbg_pls::{pretty, DebugPls, Formatter};
10///
11/// struct Foo {
12///     bar: i32,
13///     baz: String,
14/// }
15///
16/// impl DebugPls for Foo {
17///     fn fmt(&self, f: Formatter) {
18///         f.debug_struct("Foo")
19///             .field("bar", &self.bar)
20///             .field("baz", &self.baz)
21///             .finish()
22///     }
23/// }
24/// let value = Foo {
25///     bar: 10,
26///     baz: "Hello World".to_string(),
27/// };
28/// assert_eq!(
29///     format!("{}", pretty(&value)),
30///     "Foo { bar: 10, baz: \"Hello World\" }",
31/// );
32/// ```
33pub struct DebugStruct<'a> {
34    formatter: Formatter<'a>,
35    expr: syn::ExprStruct,
36}
37
38impl<'a> DebugStruct<'a> {
39    pub(crate) fn new(formatter: Formatter<'a>, name: &str) -> Self {
40        DebugStruct {
41            formatter,
42            expr: syn::ExprStruct {
43                attrs: vec![],
44                qself: None,
45                path: syn::Ident::into(syn::parse_str(name).unwrap()),
46                brace_token: syn::token::Brace::default(),
47                fields: syn::punctuated::Punctuated::new(),
48                dot2_token: None,
49                rest: None,
50            },
51        }
52    }
53
54    /// Adds the field to the struct output.
55    ///
56    /// # Panics
57    /// This will panic if the name is not a valid identifier
58    #[must_use]
59    pub fn field(mut self, name: &str, value: &dyn DebugPls) -> Self {
60        self.expr.fields.push(syn::FieldValue {
61            expr: Formatter::process(value),
62            attrs: vec![],
63            member: syn::Member::Named(syn::parse_str(name).unwrap()),
64            colon_token: Some(syn::token::Colon::default()),
65        });
66        self
67    }
68
69    /// Closes off the struct.
70    pub fn finish(self) {
71        self.formatter.write_expr(self.expr);
72    }
73
74    /// Closes off the struct with `..`.
75    pub fn finish_non_exhaustive(mut self) {
76        self.expr.dot2_token = Some(syn::token::DotDot::default());
77        self.finish();
78    }
79}
dbg_pls/debug_struct.rs

dbg_pls/
debug_struct.rs
