miniextendr_lint/rules/
s4_method_prefix.rs

1//! MXL111: `s4_*` method name on `#[miniextendr(s4)]` impl.
2//!
3//! S4 codegen auto-prepends `s4_` to every instance method name when generating
4//! the R generic. A Rust method named `s4_foo` on an `#[miniextendr(s4)]` impl
5//! produces an R generic `s4_s4_foo`, making it unreachable via the expected
6//! `s4_foo(obj, ...)` call.
7
8use crate::crate_index::CrateIndex;
9use crate::diagnostic::Diagnostic;
10use crate::lint_code::LintCode;
11
12pub fn check(index: &CrateIndex, diagnostics: &mut Vec<Diagnostic>) {
13    for (path, data) in &index.file_data {
14        for (impl_type, methods) in &data.impl_methods {
15            for entry in methods {
16                if entry.class_system != "s4" {
17                    continue;
18                }
19                // Constructors (`new`) are not auto-prefixed — they become the
20                // class constructor function, named after the type, not `s4_new`.
21                if entry.method_name == "new" {
22                    continue;
23                }
24                if let Some(rest) = entry.method_name.strip_prefix("s4_") {
25                    diagnostics.push(
26                        Diagnostic::new(
27                            LintCode::MXL111,
28                            path,
29                            entry.line,
30                            format!(
31                                "method `{impl_type}::{}` will produce R generic \
32                                 `s4_{}` (s4 codegen auto-prepends `s4_`); \
33                                 rename to `{rest}` to avoid the double prefix",
34                                entry.method_name, entry.method_name,
35                            ),
36                        )
37                        .with_help(
38                            "the macro prepends `s4_` to every S4 method name; \
39                             keep the Rust method name unprefixed",
40                        ),
41                    );
42                }
43            }
44        }
45    }
46}
miniextendr_lint/rules/s4_method_prefix.rs

miniextendr_lint/rules/
s4_method_prefix.rs
