move iter_skip_next to its own module

Author: TaKO8Ki

clippy_lints/src/methods/iter_skip_next.rs

@@ -0,0 +1,24 @@
+use crate::utils::{match_trait_method, paths, snippet, span_lint_and_sugg};
+use rustc_errors::Applicability;
+use rustc_hir as hir;
+use rustc_lint::LateContext;
+
+use super::ITER_SKIP_NEXT;
+
+pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, skip_args: &[hir::Expr<'_>]) {
+    // lint if caller of skip is an Iterator
+    if match_trait_method(cx, expr, &paths::ITERATOR) {
+        if let [caller, n] = skip_args {
+            let hint = format!(".nth({})", snippet(cx, n.span, ".."));
+            span_lint_and_sugg(
+                cx,
+                ITER_SKIP_NEXT,
+                expr.span.trim_start(caller.span).unwrap(),
+                "called `skip(..).next()` on an iterator",
+                "use `nth` instead",
+                hint,
+                Applicability::MachineApplicable,
+            );
+        }
+    }
+}

clippy_lints/src/methods/mod.rs

@@ -22,6 +22,7 @@ mod iter_count;
 mod iter_next_slice;
 mod iter_nth;
 mod iter_nth_zero;
+mod iter_skip_next;
 mod iterator_step_by_zero;
 mod manual_saturating_arithmetic;
 mod map_collect_result_unit;
@@ -1730,7 +1731,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
             ["nth", "bytes"] => bytes_nth::check(cx, expr, &arg_lists[1]),
             ["nth", ..] => iter_nth_zero::check(cx, expr, arg_lists[0]),
             ["step_by", ..] => iterator_step_by_zero::check(cx, expr, arg_lists[0]),
-            ["next", "skip"] => lint_iter_skip_next(cx, expr, arg_lists[1]),
+            ["next", "skip"] => iter_skip_next::check(cx, expr, arg_lists[1]),
             ["collect", "cloned"] => iter_cloned_collect::check(cx, expr, arg_lists[1]),
             ["as_ref"] => lint_asref(cx, expr, "as_ref", arg_lists[0]),
             ["as_mut"] => lint_asref(cx, expr, "as_mut", arg_lists[0]),
@@ -2510,24 +2511,6 @@ fn lint_unnecessary_fold(cx: &LateContext<'_>, expr: &hir::Expr<'_>, fold_args:
     }
 }
 
-fn lint_iter_skip_next(cx: &LateContext<'_>, expr: &hir::Expr<'_>, skip_args: &[hir::Expr<'_>]) {
-    // lint if caller of skip is an Iterator
-    if match_trait_method(cx, expr, &paths::ITERATOR) {
-        if let [caller, n] = skip_args {
-            let hint = format!(".nth({})", snippet(cx, n.span, ".."));
-            span_lint_and_sugg(
-                cx,
-                ITER_SKIP_NEXT,
-                expr.span.trim_start(caller.span).unwrap(),
-                "called `skip(..).next()` on an iterator",
-                "use `nth` instead",
-                hint,
-                Applicability::MachineApplicable,
-            );
-        }
-    }
-}
-
 fn derefs_to_slice<'tcx>(
     cx: &LateContext<'tcx>,
     expr: &'tcx hir::Expr<'tcx>,