src/tools/clippy/clippy_lints/src/methods/iter_skip_next.rs

   1 use crate::utils::{match_trait_method, paths, snippet, span_lint_and_sugg};
   2 use rustc_errors::Applicability;
   3 use rustc_hir as hir;
   4 use rustc_lint::LateContext;
   5
   6 use super::ITER_SKIP_NEXT;
   7
   8 pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, skip_args: &[hir::Expr<'_>]) {
   9     // lint if caller of skip is an Iterator
  10     if match_trait_method(cx, expr, &paths::ITERATOR) {
  11         if let [caller, n] = skip_args {
  12             let hint = format!(".nth({})", snippet(cx, n.span, ".."));
  13             span_lint_and_sugg(
  14                 cx,
  15                 ITER_SKIP_NEXT,
  16                 expr.span.trim_start(caller.span).unwrap(),
  17                 "called `skip(..).next()` on an iterator",
  18                 "use `nth` instead",
  19                 hint,
  20                 Applicability::MachineApplicable,
  21             );
  22         }
  23     }
  24 }