- // exclusive range plus one: `x..(y+1)`
- if_chain! {
- if let Some(higher::Range {
- start,
- end: Some(end),
- limits: RangeLimits::HalfOpen
- }) = higher::range(cx, expr);
- if let Some(y) = y_plus_one(end);
- then {
- let span = if expr.span.from_expansion() {
- expr.span
- .ctxt()
- .outer_expn_data()
- .call_site
- } else {
- expr.span
- };
- span_lint_and_then(
- cx,
- RANGE_PLUS_ONE,
- span,
- "an inclusive range would be more readable",
- |db| {
- let start = start.map_or(String::new(), |x| Sugg::hir(cx, x, "x").to_string());
- let end = Sugg::hir(cx, y, "y");
- if let Some(is_wrapped) = &snippet_opt(cx, span) {
- if is_wrapped.starts_with('(') && is_wrapped.ends_with(')') {
- db.span_suggestion(
- span,
- "use",
- format!("({}..={})", start, end),
- Applicability::MaybeIncorrect,
- );
- } else {
- db.span_suggestion(
- span,
- "use",
- format!("{}..={}", start, end),
- Applicability::MachineApplicable, // snippet
- );
- }
+fn check_range_bounds(cx: &LateContext<'_>, ex: &Expr<'_>) -> Option<(Constant, Ident, Span, Span, Ordering, bool)> {
+ if let ExprKind::Binary(ref op, l, r) = ex.kind {
+ let (inclusive, ordering) = match op.node {
+ BinOpKind::Gt => (false, Ordering::Greater),
+ BinOpKind::Ge => (true, Ordering::Greater),
+ BinOpKind::Lt => (false, Ordering::Less),
+ BinOpKind::Le => (true, Ordering::Less),
+ _ => return None,
+ };
+ if let Some(id) = match_ident(l) {
+ if let Some((c, _)) = constant(cx, cx.typeck_results(), r) {
+ return Some((c, id, l.span, r.span, ordering, inclusive));
+ }
+ } else if let Some(id) = match_ident(r) {
+ if let Some((c, _)) = constant(cx, cx.typeck_results(), l) {
+ return Some((c, id, r.span, l.span, ordering.reverse(), inclusive));
+ }
+ }
+ }
+ None
+}
+
+fn match_ident(e: &Expr<'_>) -> Option<Ident> {
+ if let ExprKind::Path(ref qpath) = e.kind {
+ if let Some(seg) = single_segment_path(qpath) {
+ if seg.args.is_none() {
+ return Some(seg.ident);
+ }
+ }
+ }
+ None
+}
+
+fn check_range_zip_with_len(cx: &LateContext<'_>, path: &PathSegment<'_>, args: &[Expr<'_>], span: Span) {
+ if_chain! {
+ if path.ident.as_str() == "zip";
+ if let [iter, zip_arg] = args;
+ // `.iter()` call
+ if let ExprKind::MethodCall(iter_path, _, iter_args, _) = iter.kind;
+ if iter_path.ident.name == sym::iter;
+ // range expression in `.zip()` call: `0..x.len()`
+ if let Some(higher::Range { start: Some(start), end: Some(end), .. }) = higher::range(zip_arg);
+ if is_integer_const(cx, start, 0);
+ // `.len()` call
+ if let ExprKind::MethodCall(len_path, _, len_args, _) = end.kind;
+ if len_path.ident.name == sym::len && len_args.len() == 1;
+ // `.iter()` and `.len()` called on same `Path`
+ if let ExprKind::Path(QPath::Resolved(_, iter_path)) = iter_args[0].kind;
+ if let ExprKind::Path(QPath::Resolved(_, len_path)) = len_args[0].kind;
+ if SpanlessEq::new(cx).eq_path_segments(iter_path.segments, len_path.segments);
+ then {
+ span_lint(cx,
+ RANGE_ZIP_WITH_LEN,
+ span,
+ &format!("it is more idiomatic to use `{}.iter().enumerate()`",
+ snippet(cx, iter_args[0].span, "_"))
+ );
+ }
+ }
+}
+
+// exclusive range plus one: `x..(y+1)`
+fn check_exclusive_range_plus_one(cx: &LateContext<'_>, expr: &Expr<'_>) {
+ if_chain! {
+ if let Some(higher::Range {
+ start,
+ end: Some(end),
+ limits: RangeLimits::HalfOpen
+ }) = higher::range(expr);
+ if let Some(y) = y_plus_one(cx, end);
+ then {
+ let span = if expr.span.from_expansion() {
+ expr.span
+ .ctxt()
+ .outer_expn_data()
+ .call_site
+ } else {
+ expr.span
+ };
+ span_lint_and_then(
+ cx,
+ RANGE_PLUS_ONE,
+ span,
+ "an inclusive range would be more readable",
+ |diag| {
+ let start = start.map_or(String::new(), |x| Sugg::hir(cx, x, "x").to_string());
+ let end = Sugg::hir(cx, y, "y");
+ if let Some(is_wrapped) = &snippet_opt(cx, span) {
+ if is_wrapped.starts_with('(') && is_wrapped.ends_with(')') {
+ diag.span_suggestion(
+ span,
+ "use",
+ format!("({}..={})", start, end),
+ Applicability::MaybeIncorrect,
+ );
+ } else {
+ diag.span_suggestion(
+ span,
+ "use",
+ format!("{}..={}", start, end),
+ Applicability::MachineApplicable, // snippet
+ );