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Add support for using qualified paths with structs in expression and pattern

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This commit is contained in:
Ryan Levick
2020-12-10 13:20:07 +01:00
committed by Ryan Levick
parent c5fbcd35a8
commit 6936349233
38 changed files with 374 additions and 187 deletions
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23
compiler/rustc_parse/src/parser/pat.rs
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@@ -859,7 +859,8 @@ impl<'a> Parser<'a> {
/// Parse a struct ("record") pattern (e.g. `Foo { ... }` or `Foo::Bar { ... }`).
fn parse_pat_struct(&mut self, qself: Option<QSelf>, path: Path) -> PResult<'a, PatKind> {
if qself.is_some() {
return self.error_qpath_before_pat(&path, "{");
// Feature gate the use of qualified paths in patterns
self.sess.gated_spans.gate(sym::more_qualified_paths, path.span);
}
self.bump();
let (fields, etc) = self.parse_pat_fields().unwrap_or_else(|mut e| {
@@ -869,27 +870,17 @@ impl<'a> Parser<'a> {
(vec![], true)
});
self.bump();
Ok(PatKind::Struct(path, fields, etc))
Ok(PatKind::Struct(qself, path, fields, etc))
}
/// Parse tuple struct or tuple variant pattern (e.g. `Foo(...)` or `Foo::Bar(...)`).
fn parse_pat_tuple_struct(&mut self, qself: Option<QSelf>, path: Path) -> PResult<'a, PatKind> {
if qself.is_some() {
return self.error_qpath_before_pat(&path, "(");
}
let (fields, _) =
self.parse_paren_comma_seq(|p| p.parse_pat_allow_top_alt(None, RecoverComma::No))?;
Ok(PatKind::TupleStruct(path, fields))
}
/// Error when there's a qualified path, e.g. `<Foo as Bar>::Baz`
/// as the path of e.g., a tuple or record struct pattern.
fn error_qpath_before_pat(&mut self, path: &Path, token: &str) -> PResult<'a, PatKind> {
let msg = &format!("unexpected `{}` after qualified path", token);
let mut err = self.struct_span_err(self.token.span, msg);
err.span_label(self.token.span, msg);
err.span_label(path.span, "the qualified path");
Err(err)
if qself.is_some() {
self.sess.gated_spans.gate(sym::more_qualified_paths, path.span);
}
Ok(PatKind::TupleStruct(qself, path, fields))
}
/// Parses the fields of a struct-like pattern.