Closure argument mismatch tweaks
- use consistent phrasing for expected and found arguments - suggest changing arugments to tuple if possible - suggest changing single tuple argument to arguments if possible
This commit is contained in:
Esteban Küber
parent
bb345a0be3
commit
7ed00caacc
@ -717,93 +717,40 @@ pub fn report_selection_error(&self,
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self.tcx.hir.span_if_local(did)
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}).map(|sp| self.tcx.sess.codemap().def_span(sp)); // the sp could be an fn def
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let found_ty_count =
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match found_trait_ref.skip_binder().substs.type_at(1).sty {
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ty::TyTuple(ref tys, _) => tys.len(),
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_ => 1,
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};
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let (expected_tys, expected_ty_count) =
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match expected_trait_ref.skip_binder().substs.type_at(1).sty {
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ty::TyTuple(ref tys, _) =>
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(tys.iter().map(|t| &t.sty).collect(), tys.len()),
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ref sty => (vec![sty], 1),
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};
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if found_ty_count == expected_ty_count {
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let found = match found_trait_ref.skip_binder().substs.type_at(1).sty {
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ty::TyTuple(ref tys, _) => tys.iter()
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.map(|_| ArgKind::empty()).collect::<Vec<_>>(),
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_ => vec![ArgKind::empty()],
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};
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let expected = match expected_trait_ref.skip_binder().substs.type_at(1).sty {
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ty::TyTuple(ref tys, _) => tys.iter()
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.map(|t| match t.sty {
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ty::TypeVariants::TyTuple(ref tys, _) => ArgKind::Tuple(
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span,
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tys.iter()
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.map(|ty| ("_".to_owned(), format!("{}", ty.sty)))
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.collect::<Vec<_>>()
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),
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_ => ArgKind::Arg("_".to_owned(), format!("{}", t.sty)),
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}).collect(),
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ref sty => vec![ArgKind::Arg("_".to_owned(), format!("{}", sty))],
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};
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if found.len()== expected.len() {
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self.report_closure_arg_mismatch(span,
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found_span,
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found_trait_ref,
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expected_trait_ref)
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} else {
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let expected_tuple = if expected_ty_count == 1 {
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expected_tys.first().and_then(|t| {
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if let &&ty::TyTuple(ref tuptys, _) = t {
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Some(tuptys.len())
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} else {
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None
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}
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})
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} else {
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None
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};
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// FIXME(#44150): Expand this to "N args expected but a N-tuple found."
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// Type of the 1st expected argument is somehow provided as type of a
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// found one in that case.
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//
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// ```
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// [1i32, 2, 3].sort_by(|(a, b)| ..)
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// // ^^^^^^^ --------
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// // expected_trait_ref: std::ops::FnMut<(&i32, &i32)>
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// // found_trait_ref: std::ops::FnMut<(&i32,)>
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// ```
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let (closure_span, closure_args) = found_did
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let (closure_span, found) = found_did
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.and_then(|did| self.tcx.hir.get_if_local(did))
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.and_then(|node| {
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if let hir::map::NodeExpr(
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&hir::Expr {
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node: hir::ExprClosure(_, ref decl, id, span, _),
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..
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}) = node
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{
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let ty_snips = decl.inputs.iter()
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.map(|ty| {
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self.tcx.sess.codemap().span_to_snippet(ty.span).ok()
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.and_then(|snip| {
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// filter out dummy spans
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if snip == "," || snip == "|" {
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None
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} else {
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Some(snip)
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}
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})
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})
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.collect::<Vec<Option<String>>>();
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.map(|node| self.get_fn_like_arguments(node))
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.unwrap_or((found_span.unwrap(), found));
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let body = self.tcx.hir.body(id);
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let pat_snips = body.arguments.iter()
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.map(|arg|
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self.tcx.sess.codemap().span_to_snippet(arg.pat.span).ok())
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.collect::<Option<Vec<String>>>();
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Some((span, pat_snips, ty_snips))
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} else {
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None
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}
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})
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.map(|(span, pat, ty)| (Some(span), Some((pat, ty))))
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.unwrap_or((None, None));
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let closure_args = closure_args.and_then(|(pat, ty)| Some((pat?, ty)));
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self.report_arg_count_mismatch(
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span,
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closure_span.or(found_span),
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expected_ty_count,
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expected_tuple,
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found_ty_count,
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closure_args,
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found_trait_ty.is_closure()
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)
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self.report_arg_count_mismatch(span,
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closure_span,
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expected,
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found,
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found_trait_ty.is_closure())
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}
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}
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@ -845,94 +792,135 @@ fn suggest_borrow_on_unsized_slice(&self,
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}
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}
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fn get_fn_like_arguments(&self, node: hir::map::Node) -> (Span, Vec<ArgKind>) {
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if let hir::map::NodeExpr(&hir::Expr {
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node: hir::ExprClosure(_, ref _decl, id, span, _),
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..
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}) = node {
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(self.tcx.sess.codemap().def_span(span), self.tcx.hir.body(id).arguments.iter()
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.map(|arg| {
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if let hir::Pat {
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node: hir::PatKind::Tuple(args, _),
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span,
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..
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} = arg.pat.clone().into_inner() {
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ArgKind::Tuple(
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span,
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args.iter().map(|pat| {
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let snippet = self.tcx.sess.codemap()
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.span_to_snippet(pat.span).unwrap();
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(snippet, "_".to_owned())
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}).collect::<Vec<_>>(),
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)
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} else {
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let name = self.tcx.sess.codemap().span_to_snippet(arg.pat.span).unwrap();
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ArgKind::Arg(name, "_".to_owned())
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}
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})
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.collect::<Vec<ArgKind>>())
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} else if let hir::map::NodeItem(&hir::Item {
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span,
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node: hir::ItemFn(ref decl, ..),
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..
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}) = node {
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(self.tcx.sess.codemap().def_span(span), decl.inputs.iter()
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.map(|arg| match arg.clone().into_inner().node {
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hir::TyTup(ref tys) => ArgKind::Tuple(
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arg.span,
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tys.iter()
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.map(|_| ("_".to_owned(), "_".to_owned()))
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.collect::<Vec<_>>(),
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),
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_ => ArgKind::Arg("_".to_owned(), "_".to_owned())
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}).collect::<Vec<ArgKind>>())
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} else {
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panic!("non-FnLike node found: {:?}", node);
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}
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}
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fn report_arg_count_mismatch(
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&self,
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span: Span,
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found_span: Option<Span>,
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expected: usize,
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expected_tuple: Option<usize>,
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found: usize,
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closure_args: Option<(Vec<String>, Vec<Option<String>>)>,
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is_closure: bool
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found_span: Span,
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expected_args: Vec<ArgKind>,
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found_args: Vec<ArgKind>,
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is_closure: bool,
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) -> DiagnosticBuilder<'tcx> {
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use std::borrow::Cow;
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let kind = if is_closure { "closure" } else { "function" };
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let args_str = |n, distinct| format!(
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"{} {}argument{}",
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n,
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if distinct && n >= 2 { "distinct " } else { "" },
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if n == 1 { "" } else { "s" },
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);
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let expected_str = if let Some(n) = expected_tuple {
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assert!(expected == 1);
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if closure_args.as_ref().map(|&(ref pats, _)| pats.len()) == Some(n) {
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Cow::from("a single tuple as argument")
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} else {
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// be verbose when numbers differ
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Cow::from(format!("a single {}-tuple as argument", n))
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let args_str = |arguments: &Vec<ArgKind>, other: &Vec<ArgKind>| {
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let arg_length = arguments.len();
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let distinct = match &other[..] {
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&[ArgKind::Tuple(..)] => true,
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_ => false,
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};
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match (arg_length, arguments.get(0)) {
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(1, Some(&ArgKind::Tuple(_, ref fields))) => {
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format!("a single {}-tuple as argument", fields.len())
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}
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_ => format!("{} {}argument{}",
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arg_length,
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if distinct && arg_length > 1 { "distinct " } else { "" },
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if arg_length == 1 { "" } else { "s" }),
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}
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} else {
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Cow::from(args_str(expected, false))
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};
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let found_str = if expected_tuple.is_some() {
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args_str(found, true)
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} else {
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args_str(found, false)
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};
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let expected_str = args_str(&expected_args, &found_args);
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let found_str = args_str(&found_args, &expected_args);
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let mut err = struct_span_err!(self.tcx.sess, span, E0593,
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let mut err = struct_span_err!(
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self.tcx.sess,
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span,
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E0593,
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"{} is expected to take {}, but it takes {}",
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kind,
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expected_str,
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found_str,
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);
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err.span_label(
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span,
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format!(
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"expected {} that takes {}",
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kind,
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expected_str,
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)
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);
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err.span_label(span, format!( "expected {} that takes {}", kind, expected_str));
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err.span_label(found_span, format!("takes {}", found_str));
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if let Some(span) = found_span {
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if let (Some(expected_tuple), Some((pats, tys))) = (expected_tuple, closure_args) {
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if expected_tuple != found || pats.len() != found {
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err.span_label(span, format!("takes {}", found_str));
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} else {
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let sugg = format!(
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"|({}){}|",
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pats.join(", "),
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// add type annotations if available
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if tys.iter().any(|ty| ty.is_some()) {
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Cow::from(format!(
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": ({})",
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tys.into_iter().map(|ty| if let Some(ty) = ty {
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ty
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} else {
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"_".to_string()
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}).collect::<Vec<String>>().join(", ")
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))
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} else {
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Cow::from("")
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},
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);
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err.span_suggestion(
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span,
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"consider changing the closure to accept a tuple",
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sugg
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);
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}
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} else {
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err.span_label(span, format!("takes {}", found_str));
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if let &[ArgKind::Tuple(_, ref fields)] = &found_args[..] {
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if fields.len() == expected_args.len() {
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let sugg = fields.iter()
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.map(|(name, _)| name.to_owned())
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.collect::<Vec<String>>().join(", ");
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err.span_suggestion(found_span,
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"change the closure to take multiple arguments instead of \
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a single tuple",
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format!("|{}|", sugg));
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}
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}
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if let &[ArgKind::Tuple(_, ref fields)] = &expected_args[..] {
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if fields.len() == found_args.len() && is_closure {
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let sugg = format!(
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"|({}){}|",
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found_args.iter()
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.map(|arg| match arg {
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ArgKind::Arg(name, _) => name.to_owned(),
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_ => "_".to_owned(),
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})
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.collect::<Vec<String>>()
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.join(", "),
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// add type annotations if available
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if found_args.iter().any(|arg| match arg {
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ArgKind::Arg(_, ty) => ty != "_",
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_ => false,
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}) {
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format!(": ({})",
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fields.iter()
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.map(|(_, ty)| ty.to_owned())
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.collect::<Vec<String>>()
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.join(", "))
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} else {
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"".to_owned()
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},
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);
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err.span_suggestion(found_span,
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"change the closure to accept a tuple instead of individual \
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arguments",
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sugg);
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}
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}
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@ -1325,3 +1313,14 @@ fn suggest_new_overflow_limit(&self, err: &mut DiagnosticBuilder) {
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suggested_limit));
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}
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}
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enum ArgKind {
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Arg(String, String),
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Tuple(Span, Vec<(String, String)>),
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}
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impl ArgKind {
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fn empty() -> ArgKind {
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ArgKind::Arg("_".to_owned(), "_".to_owned())
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}
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}
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@ -18,6 +18,8 @@ fn main() {
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//~^ ERROR closure is expected to take
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[1, 2, 3].sort_by(|(tuple, tuple2)| panic!());
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//~^ ERROR closure is expected to take
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[1, 2, 3].sort_by(|(tuple, tuple2): (usize, _)| panic!());
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//~^ ERROR closure is expected to take
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f(|| panic!());
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//~^ ERROR closure is expected to take
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@ -32,6 +34,9 @@ fn main() {
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let bar = |i, x, y| i;
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let _it = vec![1, 2, 3].into_iter().enumerate().map(bar);
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//~^ ERROR closure is expected to take
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let _it = vec![1, 2, 3].into_iter().enumerate().map(qux);
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//~^ ERROR function is expected to take
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}
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fn foo() {}
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fn qux(x: usize, y: usize) {}
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@ -14,64 +14,97 @@ error[E0593]: closure is expected to take 2 arguments, but it takes 1 argument
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| |
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| expected closure that takes 2 arguments
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error[E0593]: closure is expected to take 2 arguments, but it takes 1 argument
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error[E0593]: closure is expected to take 2 distinct arguments, but it takes a single 2-tuple as argument
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--> $DIR/closure-arg-count.rs:19:15
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|
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19 | [1, 2, 3].sort_by(|(tuple, tuple2)| panic!());
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| ^^^^^^^ ----------------- takes 1 argument
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| ^^^^^^^ ----------------- takes a single 2-tuple as argument
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| |
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| expected closure that takes 2 arguments
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| expected closure that takes 2 distinct arguments
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help: change the closure to take multiple arguments instead of a single tuple
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|
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19 | [1, 2, 3].sort_by(|tuple, tuple2| panic!());
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| ^^^^^^^^^^^^^^^
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error[E0593]: closure is expected to take 2 distinct arguments, but it takes a single 2-tuple as argument
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--> $DIR/closure-arg-count.rs:21:15
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|
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21 | [1, 2, 3].sort_by(|(tuple, tuple2): (usize, _)| panic!());
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| ^^^^^^^ ----------------------------- takes a single 2-tuple as argument
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| |
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| expected closure that takes 2 distinct arguments
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help: change the closure to take multiple arguments instead of a single tuple
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|
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21 | [1, 2, 3].sort_by(|tuple, tuple2| panic!());
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| ^^^^^^^^^^^^^^^
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error[E0593]: closure is expected to take 1 argument, but it takes 0 arguments
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--> $DIR/closure-arg-count.rs:21:5
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--> $DIR/closure-arg-count.rs:23:5
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|
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21 | f(|| panic!());
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23 | f(|| panic!());
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| ^ -- takes 0 arguments
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| |
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| expected closure that takes 1 argument
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|
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= note: required by `f`
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error[E0593]: closure is expected to take a single tuple as argument, but it takes 2 distinct arguments
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--> $DIR/closure-arg-count.rs:24:53
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|
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24 | let _it = vec![1, 2, 3].into_iter().enumerate().map(|i, x| i);
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| ^^^ ------ help: consider changing the closure to accept a tuple: `|(i, x)|`
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| |
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| expected closure that takes a single tuple as argument
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error[E0593]: closure is expected to take a single tuple as argument, but it takes 2 distinct arguments
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error[E0593]: closure is expected to take a single 2-tuple as argument, but it takes 2 distinct arguments
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--> $DIR/closure-arg-count.rs:26:53
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|
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26 | let _it = vec![1, 2, 3].into_iter().enumerate().map(|i: usize, x| i);
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| ^^^ ------------- help: consider changing the closure to accept a tuple: `|(i, x): (usize, _)|`
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26 | let _it = vec![1, 2, 3].into_iter().enumerate().map(|i, x| i);
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| ^^^ ------ takes 2 distinct arguments
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| |
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| expected closure that takes a single tuple as argument
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| expected closure that takes a single 2-tuple as argument
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help: change the closure to accept a tuple instead of individual arguments
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|
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26 | let _it = vec![1, 2, 3].into_iter().enumerate().map(|(i, x)| i);
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| ^^^^^^^^
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error[E0593]: closure is expected to take a single 2-tuple as argument, but it takes 3 distinct arguments
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error[E0593]: closure is expected to take a single 2-tuple as argument, but it takes 2 distinct arguments
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--> $DIR/closure-arg-count.rs:28:53
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|
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28 | let _it = vec![1, 2, 3].into_iter().enumerate().map(|i, x, y| i);
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28 | let _it = vec![1, 2, 3].into_iter().enumerate().map(|i: usize, x| i);
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| ^^^ ------------- takes 2 distinct arguments
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| |
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| expected closure that takes a single 2-tuple as argument
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help: change the closure to accept a tuple instead of individual arguments
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|
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28 | let _it = vec![1, 2, 3].into_iter().enumerate().map(|(i, x)| i);
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| ^^^^^^^^
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error[E0593]: closure is expected to take a single 2-tuple as argument, but it takes 3 distinct arguments
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--> $DIR/closure-arg-count.rs:30:53
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|
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30 | let _it = vec![1, 2, 3].into_iter().enumerate().map(|i, x, y| i);
|
||||
| ^^^ --------- takes 3 distinct arguments
|
||||
| |
|
||||
| expected closure that takes a single 2-tuple as argument
|
||||
|
||||
error[E0593]: function is expected to take a single 2-tuple as argument, but it takes 0 arguments
|
||||
--> $DIR/closure-arg-count.rs:30:53
|
||||
--> $DIR/closure-arg-count.rs:32:53
|
||||
|
|
||||
30 | let _it = vec![1, 2, 3].into_iter().enumerate().map(foo);
|
||||
32 | let _it = vec![1, 2, 3].into_iter().enumerate().map(foo);
|
||||
| ^^^ expected function that takes a single 2-tuple as argument
|
||||
...
|
||||
37 | fn foo() {}
|
||||
41 | fn foo() {}
|
||||
| -------- takes 0 arguments
|
||||
|
||||
error[E0593]: closure is expected to take a single 2-tuple as argument, but it takes 3 distinct arguments
|
||||
--> $DIR/closure-arg-count.rs:33:53
|
||||
--> $DIR/closure-arg-count.rs:35:53
|
||||
|
|
||||
32 | let bar = |i, x, y| i;
|
||||
34 | let bar = |i, x, y| i;
|
||||
| --------- takes 3 distinct arguments
|
||||
33 | let _it = vec![1, 2, 3].into_iter().enumerate().map(bar);
|
||||
35 | let _it = vec![1, 2, 3].into_iter().enumerate().map(bar);
|
||||
| ^^^ expected closure that takes a single 2-tuple as argument
|
||||
|
||||
error: aborting due to 9 previous errors
|
||||
error[E0593]: function is expected to take a single 2-tuple as argument, but it takes 2 distinct arguments
|
||||
--> $DIR/closure-arg-count.rs:37:53
|
||||
|
|
||||
37 | let _it = vec![1, 2, 3].into_iter().enumerate().map(qux);
|
||||
| ^^^ expected function that takes a single 2-tuple as argument
|
||||
...
|
||||
42 | fn qux(x: usize, y: usize) {}
|
||||
| -------------------------- takes 2 distinct arguments
|
||||
|
||||
error: aborting due to 11 previous errors
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user