1 use clippy_utils::diagnostics::span_lint_and_then;
2 use clippy_utils::msrvs::{self, Msrv};
3 use clippy_utils::source::{trim_span, walk_span_to_context};
4 use rustc_ast::ast::{Expr, ExprKind, LitKind, Pat, PatKind, RangeEnd, RangeLimits};
5 use rustc_errors::Applicability;
6 use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
7 use rustc_middle::lint::in_external_macro;
8 use rustc_session::{declare_tool_lint, impl_lint_pass};
11 declare_clippy_lint! {
13 /// Checks for ranges which almost include the entire range of letters from 'a' to 'z'
14 /// or digits from '0' to '9', but don't because they're a half open range.
16 /// ### Why is this bad?
17 /// This (`'a'..'z'`) is almost certainly a typo meant to include all letters.
25 /// let _ = 'a'..='z';
27 #[clippy::version = "1.63.0"]
28 pub ALMOST_COMPLETE_RANGE,
30 "almost complete range"
32 impl_lint_pass!(AlmostCompleteRange => [ALMOST_COMPLETE_RANGE]);
34 pub struct AlmostCompleteRange {
37 impl AlmostCompleteRange {
38 pub fn new(msrv: Msrv) -> Self {
42 impl EarlyLintPass for AlmostCompleteRange {
43 fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &Expr) {
44 if let ExprKind::Range(Some(start), Some(end), RangeLimits::HalfOpen) = &e.kind {
45 let ctxt = e.span.ctxt();
46 let sugg = if let Some(start) = walk_span_to_context(start.span, ctxt)
47 && let Some(end) = walk_span_to_context(end.span, ctxt)
48 && self.msrv.meets(msrvs::RANGE_INCLUSIVE)
50 Some((trim_span(cx.sess().source_map(), start.between(end)), "..="))
54 check_range(cx, e.span, start, end, sugg);
58 fn check_pat(&mut self, cx: &EarlyContext<'_>, p: &Pat) {
59 if let PatKind::Range(Some(start), Some(end), kind) = &p.kind
60 && matches!(kind.node, RangeEnd::Excluded)
62 let sugg = if self.msrv.meets(msrvs::RANGE_INCLUSIVE) {
67 check_range(cx, p.span, start, end, Some((kind.span, sugg)));
71 extract_msrv_attr!(EarlyContext);
74 fn check_range(cx: &EarlyContext<'_>, span: Span, start: &Expr, end: &Expr, sugg: Option<(Span, &str)>) {
75 if let ExprKind::Lit(start_token_lit) = start.peel_parens().kind
76 && let ExprKind::Lit(end_token_lit) = end.peel_parens().kind
79 LitKind::from_token_lit(start_token_lit),
80 LitKind::from_token_lit(end_token_lit),
83 Ok(LitKind::Byte(b'a') | LitKind::Char('a')),
84 Ok(LitKind::Byte(b'z') | LitKind::Char('z'))
87 Ok(LitKind::Byte(b'A') | LitKind::Char('A')),
88 Ok(LitKind::Byte(b'Z') | LitKind::Char('Z')),
91 Ok(LitKind::Byte(b'0') | LitKind::Char('0')),
92 Ok(LitKind::Byte(b'9') | LitKind::Char('9')),
95 && !in_external_macro(cx.sess(), span)
99 ALMOST_COMPLETE_RANGE,
101 "almost complete ascii range",
103 if let Some((span, sugg)) = sugg {
104 diag.span_suggestion(
106 "use an inclusive range",
108 Applicability::MaybeIncorrect,