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Refactor needless_collect

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This commit is contained in:
Cameron Steffen 2021-04-02 08:37:03 -05:00
parent 1931db20b1
commit a064534b9e
1 changed files with 21 additions and 59 deletions
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80
clippy_lints/src/loops/needless_collect.rs
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@ -22,7 +22,7 @@ pub(super) fn check<'tcx>(expr: &'tcx Expr<'_>, cx: &LateContext<'tcx>) {
fn check_needless_collect_direct_usage<'tcx>(expr: &'tcx Expr<'_>, cx: &LateContext<'tcx>) {
if_chain! {
if let ExprKind::MethodCall(ref method, _, ref args, _) = expr.kind;
if let ExprKind::MethodCall(ref chain_method, _, _, _) = args[0].kind;
if let ExprKind::MethodCall(ref chain_method, method0_span, _, _) = args[0].kind;
if chain_method.ident.name == sym!(collect) && is_trait_method(cx, &args[0], sym::Iterator);
if let Some(ref generic_args) = chain_method.args;
if let Some(GenericArg::Type(ref ty)) = generic_args.args.get(0);
@ -31,55 +31,28 @@ fn check_needless_collect_direct_usage<'tcx>(expr: &'tcx Expr<'_>, cx: &LateCont
|| is_type_diagnostic_item(cx, ty, sym::vecdeque_type)
|| match_type(cx, ty, &paths::BTREEMAP)
|| is_type_diagnostic_item(cx, ty, sym::hashmap_type);
then {
if method.ident.name == sym!(len) {
let span = shorten_needless_collect_span(expr);
span_lint_and_sugg(
cx,
NEEDLESS_COLLECT,
span,
NEEDLESS_COLLECT_MSG,
"replace with",
"count()".to_string(),
Applicability::MachineApplicable,
);
}
if method.ident.name == sym!(is_empty) {
let span = shorten_needless_collect_span(expr);
span_lint_and_sugg(
cx,
NEEDLESS_COLLECT,
span,
NEEDLESS_COLLECT_MSG,
"replace with",
"next().is_none()".to_string(),
Applicability::MachineApplicable,
);
}
if method.ident.name == sym!(contains) {
if let Some(sugg) = match &*method.ident.name.as_str() {
"len" => Some("count()".to_string()),
"is_empty" => Some("next().is_none()".to_string()),
"contains" => {
let contains_arg = snippet(cx, args[1].span, "??");
let span = shorten_needless_collect_span(expr);
span_lint_and_then(
cx,
NEEDLESS_COLLECT,
span,
NEEDLESS_COLLECT_MSG,
|diag| {
let (arg, pred) = contains_arg
.strip_prefix('&')
.map_or(("&x", &*contains_arg), |s| ("x", s));
diag.span_suggestion(
span,
"replace with",
format!(
"any(|{}| x == {})",
arg, pred
),
Applicability::MachineApplicable,
);
}
);
let (arg, pred) = contains_arg
.strip_prefix('&')
.map_or(("&x", &*contains_arg), |s| ("x", s));
Some(format!("any(|{}| x == {})", arg, pred))
}
_ => None,
};
then {
span_lint_and_sugg(
cx,
NEEDLESS_COLLECT,
method0_span.with_hi(expr.span.hi()),
NEEDLESS_COLLECT_MSG,
"replace with",
sugg,
Applicability::MachineApplicable,
);
}
}
}
@ -269,14 +242,3 @@ fn detect_iter_and_into_iters<'tcx>(block: &'tcx Block<'tcx>, identifier: Ident)
visitor.visit_block(block);
if visitor.seen_other { None } else { Some(visitor.uses) }
}
fn shorten_needless_collect_span(expr: &Expr<'_>) -> Span {
if_chain! {
if let ExprKind::MethodCall(.., args, _) = &expr.kind;
if let ExprKind::MethodCall(_, span, ..) = &args[0].kind;
then {
return expr.span.with_lo(span.lo());
}
}
unreachable!();
}