35 lines
1.1 KiB
Rust
35 lines
1.1 KiB
Rust
use clippy_utils::diagnostics::span_lint_and_sugg;
|
|
use clippy_utils::is_trait_method;
|
|
use rustc_errors::Applicability;
|
|
use rustc_hir as hir;
|
|
use rustc_lint::LateContext;
|
|
use rustc_middle::ty;
|
|
use rustc_span::{source_map::Span, sym};
|
|
|
|
use super::FLAT_MAP_OPTION;
|
|
use clippy_utils::ty::is_type_diagnostic_item;
|
|
|
|
pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, arg: &'tcx hir::Expr<'_>, span: Span) {
|
|
if !is_trait_method(cx, expr, sym::Iterator) {
|
|
return;
|
|
}
|
|
let arg_ty = cx.typeck_results().expr_ty_adjusted(arg);
|
|
let sig = match arg_ty.kind() {
|
|
ty::Closure(_, substs) => substs.as_closure().sig(),
|
|
_ if arg_ty.is_fn() => arg_ty.fn_sig(cx.tcx),
|
|
_ => return,
|
|
};
|
|
if !is_type_diagnostic_item(cx, sig.output().skip_binder(), sym::Option) {
|
|
return;
|
|
}
|
|
span_lint_and_sugg(
|
|
cx,
|
|
FLAT_MAP_OPTION,
|
|
span,
|
|
"used `flat_map` where `filter_map` could be used instead",
|
|
"try",
|
|
"filter_map".into(),
|
|
Applicability::MachineApplicable,
|
|
);
|
|
}
|