use rustc::hir::*;
use rustc::lint::*;
-use rustc::middle::const_val::ConstVal;
-use rustc::ty;
-use rustc_const_eval::EvalHint::ExprTypeChecked;
-use rustc_const_eval::ConstContext;
-use rustc_const_math::ConstInt;
+use rustc::ty::{self, Ty};
use std::cmp::Ordering;
+use std::collections::Bound;
use syntax::ast::LitKind;
use syntax::codemap::Span;
-use utils::paths;
-use utils::{match_type, snippet, span_note_and_lint, span_lint_and_then, in_external_macro, expr_block};
-use utils::sugg::Sugg;
+use crate::utils::paths;
+use crate::utils::{expr_block, in_external_macro, is_allowed, is_expn_of, match_qpath, match_type, multispan_sugg,
+ remove_blocks, snippet, span_lint_and_sugg, span_lint_and_then, span_note_and_lint, walk_ptrs_ty};
+use crate::utils::sugg::Sugg;
+use crate::consts::{constant, Constant};
/// **What it does:** Checks for matches with a single arm where an `if let`
/// will usually suffice.
/// _ => ()
/// }
/// ```
-declare_lint! {
+declare_clippy_lint! {
pub SINGLE_MATCH,
- Warn,
- "a match statement with a single nontrivial arm (i.e, where the other arm \
+ style,
+ "a match statement with a single nontrivial arm (i.e. where the other arm \
is `_ => {}`) instead of `if let`"
}
/// _ => bar(other_ref),
/// }
/// ```
-declare_lint! {
+declare_clippy_lint! {
pub SINGLE_MATCH_ELSE,
- Allow,
+ pedantic,
"a match statement with a two arms where the second arm's pattern is a wildcard \
instead of `if let`"
}
/// _ => frob(&x),
/// }
/// ```
-declare_lint! {
+declare_clippy_lint! {
pub MATCH_REF_PATS,
- Warn,
+ style,
"a match or `if let` with all arms prefixed with `&` instead of deref-ing the match expression"
}
/// false => bar(),
/// }
/// ```
-declare_lint! {
+declare_clippy_lint! {
pub MATCH_BOOL,
- Warn,
+ style,
"a match on a boolean expression instead of an `if..else` block"
}
/// _ => (),
/// }
/// ```
-declare_lint! {
+declare_clippy_lint! {
pub MATCH_OVERLAPPING_ARM,
- Warn,
+ style,
"a match with overlapping arms"
}
+/// **What it does:** Checks for arm which matches all errors with `Err(_)`
+/// and take drastic actions like `panic!`.
+///
+/// **Why is this bad?** It is generally a bad practice, just like
+/// catching all exceptions in java with `catch(Exception)`
+///
+/// **Known problems:** None.
+///
+/// **Example:**
+/// ```rust
+/// let x : Result(i32, &str) = Ok(3);
+/// match x {
+/// Ok(_) => println!("ok"),
+/// Err(_) => panic!("err"),
+/// }
+/// ```
+declare_clippy_lint! {
+ pub MATCH_WILD_ERR_ARM,
+ style,
+ "a match with `Err(_)` arm and take drastic actions"
+}
+
+/// **What it does:** Checks for match which is used to add a reference to an
+/// `Option` value.
+///
+/// **Why is this bad?** Using `as_ref()` or `as_mut()` instead is shorter.
+///
+/// **Known problems:** None.
+///
+/// **Example:**
+/// ```rust
+/// let x: Option<()> = None;
+/// let r: Option<&()> = match x {
+/// None => None,
+/// Some(ref v) => Some(v),
+/// };
+/// ```
+declare_clippy_lint! {
+ pub MATCH_AS_REF,
+ complexity,
+ "a match on an Option value instead of using `as_ref()` or `as_mut`"
+}
+
#[allow(missing_copy_implementations)]
pub struct MatchPass;
impl LintPass for MatchPass {
fn get_lints(&self) -> LintArray {
- lint_array!(SINGLE_MATCH,
- MATCH_REF_PATS,
- MATCH_BOOL,
- SINGLE_MATCH_ELSE,
- MATCH_OVERLAPPING_ARM)
+ lint_array!(
+ SINGLE_MATCH,
+ MATCH_REF_PATS,
+ MATCH_BOOL,
+ SINGLE_MATCH_ELSE,
+ MATCH_OVERLAPPING_ARM,
+ MATCH_WILD_ERR_ARM,
+ MATCH_AS_REF
+ )
}
}
check_single_match(cx, ex, arms, expr);
check_match_bool(cx, ex, arms, expr);
check_overlapping_arms(cx, ex, arms);
+ check_wild_err_arm(cx, ex, arms);
+ check_match_as_ref(cx, ex, arms, expr);
}
- if let ExprMatch(ref ex, ref arms, source) = expr.node {
- check_match_ref_pats(cx, ex, arms, source, expr);
+ if let ExprMatch(ref ex, ref arms, _) = expr.node {
+ check_match_ref_pats(cx, ex, arms, expr);
}
}
}
if arms.len() == 2 &&
arms[0].pats.len() == 1 && arms[0].guard.is_none() &&
arms[1].pats.len() == 1 && arms[1].guard.is_none() {
- let els = if is_unit_expr(&arms[1].body) {
+ let els = remove_blocks(&arms[1].body);
+ let els = if is_unit_expr(els) {
None
- } else if let ExprBlock(_) = arms[1].body.node {
+ } else if let ExprBlock(_, _) = els.node {
// matches with blocks that contain statements are prettier as `if let + else`
- Some(&*arms[1].body)
+ Some(els)
} else {
// allow match arms with just expressions
return;
};
let ty = cx.tables.expr_ty(ex);
- if ty.sty != ty::TyBool || cx.current_level(MATCH_BOOL) == Allow {
+ if ty.sty != ty::TyBool || is_allowed(cx, MATCH_BOOL, ex.id) {
check_single_match_single_pattern(cx, ex, arms, expr, els);
check_single_match_opt_like(cx, ex, arms, expr, ty, els);
}
fn check_single_match_single_pattern(cx: &LateContext, ex: &Expr, arms: &[Arm], expr: &Expr, els: Option<&Expr>) {
if arms[1].pats[0].node == PatKind::Wild {
- let lint = if els.is_some() {
- SINGLE_MATCH_ELSE
- } else {
- SINGLE_MATCH
- };
- let els_str = els.map_or(String::new(), |els| format!(" else {}", expr_block(cx, els, None, "..")));
- span_lint_and_then(cx,
- lint,
- expr.span,
- "you seem to be trying to use match for destructuring a single pattern. \
- Consider using `if let`",
- |db| {
- db.span_suggestion(expr.span,
- "try this",
- format!("if let {} = {} {}{}",
- snippet(cx, arms[0].pats[0].span, ".."),
- snippet(cx, ex.span, ".."),
- expr_block(cx, &arms[0].body, None, ".."),
- els_str));
- });
+ report_single_match_single_pattern(cx, ex, arms, expr, els);
}
}
-fn check_single_match_opt_like(
- cx: &LateContext,
- ex: &Expr,
- arms: &[Arm],
- expr: &Expr,
- ty: ty::Ty,
- els: Option<&Expr>
-) {
+fn report_single_match_single_pattern(cx: &LateContext, ex: &Expr, arms: &[Arm], expr: &Expr, els: Option<&Expr>) {
+ let lint = if els.is_some() {
+ SINGLE_MATCH_ELSE
+ } else {
+ SINGLE_MATCH
+ };
+ let els_str = els.map_or(String::new(), |els| format!(" else {}", expr_block(cx, els, None, "..")));
+ span_lint_and_sugg(
+ cx,
+ lint,
+ expr.span,
+ "you seem to be trying to use match for destructuring a single pattern. Consider using `if \
+ let`",
+ "try this",
+ format!(
+ "if let {} = {} {}{}",
+ snippet(cx, arms[0].pats[0].span, ".."),
+ snippet(cx, ex.span, ".."),
+ expr_block(cx, &arms[0].body, None, ".."),
+ els_str
+ ),
+ );
+}
+
+fn check_single_match_opt_like(cx: &LateContext, ex: &Expr, arms: &[Arm], expr: &Expr, ty: Ty, els: Option<&Expr>) {
// list of candidate Enums we know will never get any more members
- let candidates = &[(&paths::COW, "Borrowed"),
- (&paths::COW, "Cow::Borrowed"),
- (&paths::COW, "Cow::Owned"),
- (&paths::COW, "Owned"),
- (&paths::OPTION, "None"),
- (&paths::RESULT, "Err"),
- (&paths::RESULT, "Ok")];
+ let candidates = &[
+ (&paths::COW, "Borrowed"),
+ (&paths::COW, "Cow::Borrowed"),
+ (&paths::COW, "Cow::Owned"),
+ (&paths::COW, "Owned"),
+ (&paths::OPTION, "None"),
+ (&paths::RESULT, "Err"),
+ (&paths::RESULT, "Ok"),
+ ];
let path = match arms[1].pats[0].node {
PatKind::TupleStruct(ref path, ref inner, _) => {
}
print::to_string(print::NO_ANN, |s| s.print_qpath(path, false))
},
- PatKind::Binding(BindByValue(MutImmutable), _, ident, None) => ident.node.to_string(),
+ PatKind::Binding(BindingAnnotation::Unannotated, _, ident, None) => ident.node.to_string(),
PatKind::Path(ref path) => print::to_string(print::NO_ANN, |s| s.print_qpath(path, false)),
_ => return,
};
for &(ty_path, pat_path) in candidates {
- if &path == pat_path && match_type(cx, ty, ty_path) {
- let lint = if els.is_some() {
- SINGLE_MATCH_ELSE
- } else {
- SINGLE_MATCH
- };
- let els_str = els.map_or(String::new(), |els| format!(" else {}", expr_block(cx, els, None, "..")));
- span_lint_and_then(cx,
- lint,
- expr.span,
- "you seem to be trying to use match for destructuring a single pattern. Consider \
- using `if let`",
- |db| {
- db.span_suggestion(expr.span,
- "try this",
- format!("if let {} = {} {}{}",
- snippet(cx, arms[0].pats[0].span, ".."),
- snippet(cx, ex.span, ".."),
- expr_block(cx, &arms[0].body, None, ".."),
- els_str));
- });
+ if path == *pat_path && match_type(cx, ty, ty_path) {
+ report_single_match_single_pattern(cx, ex, arms, expr, els);
}
}
}
fn check_match_bool(cx: &LateContext, ex: &Expr, arms: &[Arm], expr: &Expr) {
// type of expression == bool
if cx.tables.expr_ty(ex).sty == ty::TyBool {
- span_lint_and_then(cx,
- MATCH_BOOL,
- expr.span,
- "you seem to be trying to match on a boolean expression",
- move |db| {
- if arms.len() == 2 && arms[0].pats.len() == 1 {
- // no guards
- let exprs = if let PatKind::Lit(ref arm_bool) = arms[0].pats[0].node {
- if let ExprLit(ref lit) = arm_bool.node {
- match lit.node {
- LitKind::Bool(true) => Some((&*arms[0].body, &*arms[1].body)),
- LitKind::Bool(false) => Some((&*arms[1].body, &*arms[0].body)),
- _ => None,
+ span_lint_and_then(
+ cx,
+ MATCH_BOOL,
+ expr.span,
+ "you seem to be trying to match on a boolean expression",
+ move |db| {
+ if arms.len() == 2 && arms[0].pats.len() == 1 {
+ // no guards
+ let exprs = if let PatKind::Lit(ref arm_bool) = arms[0].pats[0].node {
+ if let ExprLit(ref lit) = arm_bool.node {
+ match lit.node {
+ LitKind::Bool(true) => Some((&*arms[0].body, &*arms[1].body)),
+ LitKind::Bool(false) => Some((&*arms[1].body, &*arms[0].body)),
+ _ => None,
+ }
+ } else {
+ None
}
} else {
None
- }
- } else {
- None
- };
-
- if let Some((true_expr, false_expr)) = exprs {
- let sugg = match (is_unit_expr(true_expr), is_unit_expr(false_expr)) {
- (false, false) => {
- Some(format!("if {} {} else {}",
- snippet(cx, ex.span, "b"),
- expr_block(cx, true_expr, None, ".."),
- expr_block(cx, false_expr, None, "..")))
- },
- (false, true) => {
- Some(format!("if {} {}", snippet(cx, ex.span, "b"), expr_block(cx, true_expr, None, "..")))
- },
- (true, false) => {
- let test = Sugg::hir(cx, ex, "..");
- Some(format!("if {} {}", !test, expr_block(cx, false_expr, None, "..")))
- },
- (true, true) => None,
};
- if let Some(sugg) = sugg {
- db.span_suggestion(expr.span, "consider using an if/else expression", sugg);
+ if let Some((true_expr, false_expr)) = exprs {
+ let sugg = match (is_unit_expr(true_expr), is_unit_expr(false_expr)) {
+ (false, false) => Some(format!(
+ "if {} {} else {}",
+ snippet(cx, ex.span, "b"),
+ expr_block(cx, true_expr, None, ".."),
+ expr_block(cx, false_expr, None, "..")
+ )),
+ (false, true) => Some(format!(
+ "if {} {}",
+ snippet(cx, ex.span, "b"),
+ expr_block(cx, true_expr, None, "..")
+ )),
+ (true, false) => {
+ let test = Sugg::hir(cx, ex, "..");
+ Some(format!("if {} {}", !test, expr_block(cx, false_expr, None, "..")))
+ },
+ (true, true) => None,
+ };
+
+ if let Some(sugg) = sugg {
+ db.span_suggestion(expr.span, "consider using an if/else expression", sugg);
+ }
}
}
- }
-
- });
+ },
+ );
}
}
-fn check_overlapping_arms(cx: &LateContext, ex: &Expr, arms: &[Arm]) {
+fn check_overlapping_arms<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, ex: &'tcx Expr, arms: &'tcx [Arm]) {
if arms.len() >= 2 && cx.tables.expr_ty(ex).is_integral() {
let ranges = all_ranges(cx, arms);
let type_ranges = type_ranges(&ranges);
if !type_ranges.is_empty() {
if let Some((start, end)) = overlapping(&type_ranges) {
- span_note_and_lint(cx,
- MATCH_OVERLAPPING_ARM,
- start.span,
- "some ranges overlap",
- end.span,
- "overlaps with this");
+ span_note_and_lint(
+ cx,
+ MATCH_OVERLAPPING_ARM,
+ start.span,
+ "some ranges overlap",
+ end.span,
+ "overlaps with this",
+ );
+ }
+ }
+ }
+}
+
+fn check_wild_err_arm(cx: &LateContext, ex: &Expr, arms: &[Arm]) {
+ let ex_ty = walk_ptrs_ty(cx.tables.expr_ty(ex));
+ if match_type(cx, ex_ty, &paths::RESULT) {
+ for arm in arms {
+ if let PatKind::TupleStruct(ref path, ref inner, _) = arm.pats[0].node {
+ let path_str = print::to_string(print::NO_ANN, |s| s.print_qpath(path, false));
+ if_chain! {
+ if path_str == "Err";
+ if inner.iter().any(|pat| pat.node == PatKind::Wild);
+ if let ExprBlock(ref block, _) = arm.body.node;
+ if is_panic_block(block);
+ then {
+ // `Err(_)` arm with `panic!` found
+ span_note_and_lint(cx,
+ MATCH_WILD_ERR_ARM,
+ arm.pats[0].span,
+ "Err(_) will match all errors, maybe not a good idea",
+ arm.pats[0].span,
+ "to remove this warning, match each error seperately \
+ or use unreachable macro");
+ }
+ }
}
}
}
}
-fn check_match_ref_pats(cx: &LateContext, ex: &Expr, arms: &[Arm], source: MatchSource, expr: &Expr) {
+// If the block contains only a `panic!` macro (as expression or statement)
+fn is_panic_block(block: &Block) -> bool {
+ match (&block.expr, block.stmts.len(), block.stmts.first()) {
+ (&Some(ref exp), 0, _) => {
+ is_expn_of(exp.span, "panic").is_some() && is_expn_of(exp.span, "unreachable").is_none()
+ },
+ (&None, 1, Some(stmt)) => {
+ is_expn_of(stmt.span, "panic").is_some() && is_expn_of(stmt.span, "unreachable").is_none()
+ },
+ _ => false,
+ }
+}
+
+fn check_match_ref_pats(cx: &LateContext, ex: &Expr, arms: &[Arm], expr: &Expr) {
if has_only_ref_pats(arms) {
- if let ExprAddrOf(Mutability::MutImmutable, ref inner) = ex.node {
- span_lint_and_then(cx,
- MATCH_REF_PATS,
- expr.span,
- "you don't need to add `&` to both the expression and the patterns",
- |db| {
- let inner = Sugg::hir(cx, inner, "..");
- let template = match_template(expr.span, source, inner);
- db.span_suggestion(expr.span, "try", template);
- });
+ let mut suggs = Vec::new();
+ let (title, msg) = if let ExprAddrOf(Mutability::MutImmutable, ref inner) = ex.node {
+ suggs.push((ex.span, Sugg::hir(cx, inner, "..").to_string()));
+ (
+ "you don't need to add `&` to both the expression and the patterns",
+ "try",
+ )
} else {
- span_lint_and_then(cx,
- MATCH_REF_PATS,
- expr.span,
- "you don't need to add `&` to all patterns",
- |db| {
- let ex = Sugg::hir(cx, ex, "..");
- let template = match_template(expr.span, source, ex.deref());
- db.span_suggestion(expr.span,
- "instead of prefixing all patterns with `&`, you can dereference the expression",
- template);
- });
+ suggs.push((ex.span, Sugg::hir(cx, ex, "..").deref().to_string()));
+ (
+ "you don't need to add `&` to all patterns",
+ "instead of prefixing all patterns with `&`, you can dereference the expression",
+ )
+ };
+
+ suggs.extend(arms.iter().flat_map(|a| &a.pats).filter_map(|p| {
+ if let PatKind::Ref(ref refp, _) = p.node {
+ Some((p.span, snippet(cx, refp.span, "..").to_string()))
+ } else {
+ None
+ }
+ }));
+
+ span_lint_and_then(cx, MATCH_REF_PATS, expr.span, title, |db| {
+ multispan_sugg(db, msg.to_owned(), suggs);
+ });
+ }
+}
+
+fn check_match_as_ref(cx: &LateContext, ex: &Expr, arms: &[Arm], expr: &Expr) {
+ if arms.len() == 2 &&
+ arms[0].pats.len() == 1 && arms[0].guard.is_none() &&
+ arms[1].pats.len() == 1 && arms[1].guard.is_none() {
+ let arm_ref: Option<BindingAnnotation> = if is_none_arm(&arms[0]) {
+ is_ref_some_arm(&arms[1])
+ } else if is_none_arm(&arms[1]) {
+ is_ref_some_arm(&arms[0])
+ } else {
+ None
+ };
+ if let Some(rb) = arm_ref {
+ let suggestion = if rb == BindingAnnotation::Ref { "as_ref" } else { "as_mut" };
+ span_lint_and_sugg(
+ cx,
+ MATCH_AS_REF,
+ expr.span,
+ &format!("use {}() instead", suggestion),
+ "try this",
+ format!("{}.{}()", snippet(cx, ex.span, "_"), suggestion)
+ )
}
}
}
/// Get all arms that are unbounded `PatRange`s.
-fn all_ranges(cx: &LateContext, arms: &[Arm]) -> Vec<SpannedRange<ConstVal>> {
- let constcx = ConstContext::with_tables(cx.tcx, cx.tables);
+fn all_ranges<'a, 'tcx>(
+ cx: &LateContext<'a, 'tcx>,
+ arms: &'tcx [Arm],
+) -> Vec<SpannedRange<Constant>> {
arms.iter()
.flat_map(|arm| {
- if let Arm { ref pats, guard: None, .. } = *arm {
- pats.iter()
- } else {
- [].iter()
- }
- .filter_map(|pat| {
- if_let_chain! {[
- let PatKind::Range(ref lhs, ref rhs, _) = pat.node,
- let Ok(lhs) = constcx.eval(lhs, ExprTypeChecked),
- let Ok(rhs) = constcx.eval(rhs, ExprTypeChecked)
- ], {
+ if let Arm {
+ ref pats,
+ guard: None,
+ ..
+ } = *arm
+ {
+ pats.iter()
+ } else {
+ [].iter()
+ }.filter_map(|pat| {
+ if let PatKind::Range(ref lhs, ref rhs, ref range_end) = pat.node {
+ let lhs = constant(cx, cx.tables, lhs)?.0;
+ let rhs = constant(cx, cx.tables, rhs)?.0;
+ let rhs = match *range_end {
+ RangeEnd::Included => Bound::Included(rhs),
+ RangeEnd::Excluded => Bound::Excluded(rhs),
+ };
return Some(SpannedRange { span: pat.span, node: (lhs, rhs) });
- }}
+ }
- if_let_chain! {[
- let PatKind::Lit(ref value) = pat.node,
- let Ok(value) = constcx.eval(value, ExprTypeChecked)
- ], {
- return Some(SpannedRange { span: pat.span, node: (value.clone(), value) });
- }}
+ if let PatKind::Lit(ref value) = pat.node {
+ let value = constant(cx, cx.tables, value)?.0;
+ return Some(SpannedRange { span: pat.span, node: (value.clone(), Bound::Included(value)) });
+ }
- None
- })
+ None
+ })
})
.collect()
}
#[derive(Debug, Eq, PartialEq)]
pub struct SpannedRange<T> {
pub span: Span,
- pub node: (T, T),
+ pub node: (T, Bound<T>),
}
-type TypedRanges = Vec<SpannedRange<ConstInt>>;
+type TypedRanges = Vec<SpannedRange<u128>>;
-/// Get all `Int` ranges or all `Uint` ranges. Mixed types are an error anyway and other types than
+/// Get all `Int` ranges or all `Uint` ranges. Mixed types are an error anyway
+/// and other types than
/// `Uint` and `Int` probably don't make sense.
-fn type_ranges(ranges: &[SpannedRange<ConstVal>]) -> TypedRanges {
- ranges.iter()
- .filter_map(|range| if let (ConstVal::Integral(start), ConstVal::Integral(end)) = range.node {
- Some(SpannedRange {
+fn type_ranges(ranges: &[SpannedRange<Constant>]) -> TypedRanges {
+ ranges
+ .iter()
+ .filter_map(|range| match range.node {
+ (
+ Constant::Int(start),
+ Bound::Included(Constant::Int(end)),
+ ) => Some(SpannedRange {
span: range.span,
- node: (start, end),
- })
- } else {
- None
+ node: (start, Bound::Included(end)),
+ }),
+ (
+ Constant::Int(start),
+ Bound::Excluded(Constant::Int(end)),
+ ) => Some(SpannedRange {
+ span: range.span,
+ node: (start, Bound::Excluded(end)),
+ }),
+ (
+ Constant::Int(start),
+ Bound::Unbounded,
+ ) => Some(SpannedRange {
+ span: range.span,
+ node: (start, Bound::Unbounded),
+ }),
+ _ => None,
})
.collect()
}
fn is_unit_expr(expr: &Expr) -> bool {
match expr.node {
ExprTup(ref v) if v.is_empty() => true,
- ExprBlock(ref b) if b.stmts.is_empty() && b.expr.is_none() => true,
+ ExprBlock(ref b, _) if b.stmts.is_empty() && b.expr.is_none() => true,
+ _ => false,
+ }
+}
+
+// Checks if arm has the form `None => None`
+fn is_none_arm(arm: &Arm) -> bool {
+ match arm.pats[0].node {
+ PatKind::Path(ref path) if match_qpath(path, &paths::OPTION_NONE) => true,
_ => false,
}
}
+// Checks if arm has the form `Some(ref v) => Some(v)` (checks for `ref` and `ref mut`)
+fn is_ref_some_arm(arm: &Arm) -> Option<BindingAnnotation> {
+ if_chain! {
+ if let PatKind::TupleStruct(ref path, ref pats, _) = arm.pats[0].node;
+ if pats.len() == 1 && match_qpath(path, &paths::OPTION_SOME);
+ if let PatKind::Binding(rb, _, ref ident, _) = pats[0].node;
+ if rb == BindingAnnotation::Ref || rb == BindingAnnotation::RefMut;
+ if let ExprCall(ref e, ref args) = remove_blocks(&arm.body).node;
+ if let ExprPath(ref some_path) = e.node;
+ if match_qpath(some_path, &paths::OPTION_SOME) && args.len() == 1;
+ if let ExprPath(ref qpath) = args[0].node;
+ if let &QPath::Resolved(_, ref path2) = qpath;
+ if path2.segments.len() == 1 && ident.node == path2.segments[0].name;
+ then {
+ return Some(rb)
+ }
+ }
+ None
+}
+
fn has_only_ref_pats(arms: &[Arm]) -> bool {
let mapped = arms.iter()
.flat_map(|a| &a.pats)
.map(|p| {
match p.node {
- PatKind::Ref(..) => Some(true), // &-patterns
+ PatKind::Ref(..) => Some(true), // &-patterns
PatKind::Wild => Some(false), // an "anything" wildcard is also fine
- _ => None, // any other pattern is not fine
+ _ => None, // any other pattern is not fine
}
})
.collect::<Option<Vec<bool>>>();
mapped.map_or(false, |v| v.iter().any(|el| *el))
}
-fn match_template(span: Span, source: MatchSource, expr: Sugg) -> String {
- match source {
- MatchSource::Normal => format!("match {} {{ .. }}", expr),
- MatchSource::IfLetDesugar { .. } => format!("if let .. = {} {{ .. }}", expr),
- MatchSource::WhileLetDesugar => format!("while let .. = {} {{ .. }}", expr),
- MatchSource::ForLoopDesugar => span_bug!(span, "for loop desugared to match with &-patterns!"),
- MatchSource::TryDesugar => span_bug!(span, "`?` operator desugared to match with &-patterns!"),
- }
-}
-
pub fn overlapping<T>(ranges: &[SpannedRange<T>]) -> Option<(&SpannedRange<T>, &SpannedRange<T>)>
- where T: Copy + Ord
+where
+ T: Copy + Ord,
{
#[derive(Copy, Clone, Debug, Eq, PartialEq)]
enum Kind<'a, T: 'a> {
Start(T, &'a SpannedRange<T>),
- End(T, &'a SpannedRange<T>),
+ End(Bound<T>, &'a SpannedRange<T>),
}
impl<'a, T: Copy> Kind<'a, T> {
fn range(&self) -> &'a SpannedRange<T> {
match *self {
- Kind::Start(_, r) |
- Kind::End(_, r) => r,
+ Kind::Start(_, r) | Kind::End(_, r) => r,
}
}
- fn value(self) -> T {
+ fn value(self) -> Bound<T> {
match self {
- Kind::Start(t, _) |
+ Kind::Start(t, _) => Bound::Included(t),
Kind::End(t, _) => t,
}
}
impl<'a, T: Copy + Ord> Ord for Kind<'a, T> {
fn cmp(&self, other: &Self) -> Ordering {
- self.value().cmp(&other.value())
+ match (self.value(), other.value()) {
+ (Bound::Included(a), Bound::Included(b)) | (Bound::Excluded(a), Bound::Excluded(b)) => a.cmp(&b),
+ // Range patterns cannot be unbounded (yet)
+ (Bound::Unbounded, _) | (_, Bound::Unbounded) => unimplemented!(),
+ (Bound::Included(a), Bound::Excluded(b)) => match a.cmp(&b) {
+ Ordering::Equal => Ordering::Greater,
+ other => other,
+ },
+ (Bound::Excluded(a), Bound::Included(b)) => match a.cmp(&b) {
+ Ordering::Equal => Ordering::Less,
+ other => other,
+ },
+ }
}
}
for (a, b) in values.iter().zip(values.iter().skip(1)) {
match (a, b) {
- (&Kind::Start(_, ra), &Kind::End(_, rb)) => {
- if ra.node != rb.node {
- return Some((ra, rb));
- }
+ (&Kind::Start(_, ra), &Kind::End(_, rb)) => if ra.node != rb.node {
+ return Some((ra, rb));
},
- (&Kind::End(a, _), &Kind::Start(b, _)) if a != b => (),
+ (&Kind::End(a, _), &Kind::Start(b, _)) if a != Bound::Included(b) => (),
_ => return Some((a.range(), b.range())),
}
}
projects / rust.git / blobdiff