--- /dev/null
+use super::get_span_of_entire_for_loop;
+use crate::utils::{indent_of, single_segment_path, snippet, span_lint_and_sugg};
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::{BorrowKind, Expr, ExprKind, Pat, PatKind};
+use rustc_lint::LateContext;
+
+pub(super) fn check_for_single_element_loop<'tcx>(
+ cx: &LateContext<'tcx>,
+ pat: &'tcx Pat<'_>,
+ arg: &'tcx Expr<'_>,
+ body: &'tcx Expr<'_>,
+ expr: &'tcx Expr<'_>,
+) {
+ if_chain! {
+ if let ExprKind::AddrOf(BorrowKind::Ref, _, ref arg_expr) = arg.kind;
+ if let PatKind::Binding(.., target, _) = pat.kind;
+ if let ExprKind::Array([arg_expression]) = arg_expr.kind;
+ if let ExprKind::Path(ref list_item) = arg_expression.kind;
+ if let Some(list_item_name) = single_segment_path(list_item).map(|ps| ps.ident.name);
+ if let ExprKind::Block(ref block, _) = body.kind;
+ if !block.stmts.is_empty();
+
+ then {
+ let for_span = get_span_of_entire_for_loop(expr);
+ let mut block_str = snippet(cx, block.span, "..").into_owned();
+ block_str.remove(0);
+ block_str.pop();
+
+
+ span_lint_and_sugg(
+ cx,
+ super::SINGLE_ELEMENT_LOOP,
+ for_span,
+ "for loop over a single element",
+ "try",
+ format!("{{\n{}let {} = &{};{}}}", " ".repeat(indent_of(cx, block.stmts[0].span).unwrap_or(0)), target.name, list_item_name, block_str),
+ Applicability::MachineApplicable
+ )
+ }
+ }
+}
mod for_loop_over_map_kv;
mod for_loop_range;
mod for_mut_range_bound;
+mod for_single_element_loop;
mod manual_flatten;
mod utils;
use crate::utils::sugg::Sugg;
use crate::utils::usage::mutated_variables;
use crate::utils::{
- get_enclosing_block, get_parent_expr, get_trait_def_id, higher, implements_trait, indent_of, is_in_panic_handler,
+ get_enclosing_block, get_parent_expr, get_trait_def_id, higher, implements_trait, is_in_panic_handler,
is_integer_const, is_no_std_crate, is_refutable, is_type_diagnostic_item, last_path_segment, match_trait_method,
- match_type, path_to_local, path_to_local_id, paths, single_segment_path, snippet, snippet_with_applicability,
+ match_type, path_to_local, path_to_local_id, paths, snippet, snippet_with_applicability,
snippet_with_macro_callsite, span_lint, span_lint_and_help, span_lint_and_sugg, span_lint_and_then, sugg,
};
use if_chain::if_chain;
for_loop_arg::check_for_loop_arg(cx, pat, arg, expr);
for_loop_over_map_kv::check_for_loop_over_map_kv(cx, pat, arg, body, expr);
for_mut_range_bound::check_for_mut_range_bound(cx, arg, body);
- check_for_single_element_loop(cx, pat, arg, body, expr);
+ for_single_element_loop::check_for_single_element_loop(cx, pat, arg, body, expr);
detect_same_item_push(cx, pat, arg, body, expr);
manual_flatten::check_manual_flatten(cx, pat, arg, body, span);
}
}
}
-fn check_for_single_element_loop<'tcx>(
- cx: &LateContext<'tcx>,
- pat: &'tcx Pat<'_>,
- arg: &'tcx Expr<'_>,
- body: &'tcx Expr<'_>,
- expr: &'tcx Expr<'_>,
-) {
- if_chain! {
- if let ExprKind::AddrOf(BorrowKind::Ref, _, ref arg_expr) = arg.kind;
- if let PatKind::Binding(.., target, _) = pat.kind;
- if let ExprKind::Array([arg_expression]) = arg_expr.kind;
- if let ExprKind::Path(ref list_item) = arg_expression.kind;
- if let Some(list_item_name) = single_segment_path(list_item).map(|ps| ps.ident.name);
- if let ExprKind::Block(ref block, _) = body.kind;
- if !block.stmts.is_empty();
-
- then {
- let for_span = get_span_of_entire_for_loop(expr);
- let mut block_str = snippet(cx, block.span, "..").into_owned();
- block_str.remove(0);
- block_str.pop();
-
-
- span_lint_and_sugg(
- cx,
- SINGLE_ELEMENT_LOOP,
- for_span,
- "for loop over a single element",
- "try",
- format!("{{\n{}let {} = &{};{}}}", " ".repeat(indent_of(cx, block.stmts[0].span).unwrap_or(0)), target.name, list_item_name, block_str),
- Applicability::MachineApplicable
- )
- }
- }
-}
-
fn is_used_inside<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, container: &'tcx Expr<'_>) -> bool {
let def_id = match path_to_local(expr) {
Some(id) => id,