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

   1 use crate::methods::get_hint_if_single_char_arg;
   2 use crate::utils::span_lint_and_sugg;
   3 use rustc_errors::Applicability;
   4 use rustc_hir as hir;
   5 use rustc_lint::LateContext;
   6
   7 use super::SINGLE_CHAR_PATTERN;
   8
   9 /// lint for length-1 `str`s for methods in `PATTERN_METHODS`
  10 pub(super) fn check(cx: &LateContext<'_>, _expr: &hir::Expr<'_>, arg: &hir::Expr<'_>) {
  11     let mut applicability = Applicability::MachineApplicable;
  12     if let Some(hint) = get_hint_if_single_char_arg(cx, arg, &mut applicability) {
  13         span_lint_and_sugg(
  14             cx,
  15             SINGLE_CHAR_PATTERN,
  16             arg.span,
  17             "single-character string constant used as pattern",
  18             "try using a `char` instead",
  19             hint,
  20             applicability,
  21         );
  22     }
  23 }