let (span, e) = self.interpolated_or_expr_span(e)?;
(lo.to(span), ExprKind::Box(e))
}
- _ => return self.parse_dot_or_call_expr(Some(attrs))
+ token::Ident(..) if self.token.is_ident_named("not") => {
+ // `not` is just an ordinary identifier in Rust-the-language,
+ // but as `rustc`-the-compiler, we can issue clever diagnostics
+ // for confused users who really want to say `!`
+ let token_cannot_continue_expr = |t: &token::Token| match *t {
+ // These tokens can start an expression after `!`, but
+ // can't continue an expression after an ident
+ token::Ident(ident, is_raw) => token::ident_can_begin_expr(ident, is_raw),
+ token::Literal(..) | token::Pound => true,
+ token::Interpolated(ref nt) => match nt.0 {
+ token::NtIdent(..) | token::NtExpr(..) |
+ token::NtBlock(..) | token::NtPath(..) => true,
+ _ => false,
+ },
+ _ => false
+ };
+ let cannot_continue_expr = self.look_ahead(1, token_cannot_continue_expr);
+ if cannot_continue_expr {
+ self.bump();
+ // Emit the error ...
+ let mut err = self.diagnostic()
+ .struct_span_err(self.span,
+ &format!("unexpected {} after identifier",
+ self.this_token_descr()));
+ // span the `not` plus trailing whitespace to avoid
+ // trailing whitespace after the `!` in our suggestion
+ let to_replace = self.sess.codemap()
+ .span_until_non_whitespace(lo.to(self.span));
+ err.span_suggestion_short(to_replace,
+ "use `!` to perform logical negation",
+ "!".to_owned());
+ err.emit();
+ // —and recover! (just as if we were in the block
+ // for the `token::Not` arm)
+ let e = self.parse_prefix_expr(None);
+ let (span, e) = self.interpolated_or_expr_span(e)?;
+ (lo.to(span), self.mk_unary(UnOp::Not, e))
+ } else {
+ return self.parse_dot_or_call_expr(Some(attrs));
+ }
+ }
+ _ => { return self.parse_dot_or_call_expr(Some(attrs)); }
};
return Ok(self.mk_expr(lo.to(hi), ex, attrs));
}
}
}
-fn ident_can_begin_expr(ident: ast::Ident, is_raw: bool) -> bool {
+pub(crate) fn ident_can_begin_expr(ident: ast::Ident, is_raw: bool) -> bool {
let ident_token: Token = Ident(ident, is_raw);
!ident_token.is_reserved_ident() ||
self.lifetime().is_some()
}
+ /// Returns `true` if the token is a identifier whose name is the given
+ /// string slice.
+ pub fn is_ident_named(&self, name: &str) -> bool {
+ match self.ident() {
+ Some((ident, _)) => ident.name.as_str() == name,
+ None => false
+ }
+ }
+
/// Returns `true` if the token is a documentation comment.
pub fn is_doc_comment(&self) -> bool {
match *self {
--- /dev/null
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn gratitude() {
+ let for_you = false;
+ if not for_you {
+ //~^ ERROR unexpected `for_you` after identifier
+ println!("I couldn't");
+ }
+}
+
+fn qualification() {
+ let the_worst = true;
+ while not the_worst {
+ //~^ ERROR unexpected `the_worst` after identifier
+ println!("still pretty bad");
+ }
+}
+
+fn should_we() {
+ let not = true;
+ if not // lack of braces is [sic]
+ println!("Then when?");
+ //~^ ERROR expected `{`, found `;
+ //~| ERROR unexpected `println` after identifier
+}
+
+fn sleepy() {
+ let resource = not 2;
+ //~^ ERROR unexpected `2` after identifier
+}
+
+fn main() {
+ let be_smothered_out_before = true;
+ let young_souls = not be_smothered_out_before;
+ //~^ ERROR unexpected `be_smothered_out_before` after identifier
+}
--- /dev/null
+error: unexpected `for_you` after identifier
+ --> $DIR/issue-46836-identifier-not-instead-of-negation.rs:13:12
+ |
+LL | if not for_you {
+ | ----^^^^^^^
+ | |
+ | help: use `!` to perform logical negation
+
+error: unexpected `the_worst` after identifier
+ --> $DIR/issue-46836-identifier-not-instead-of-negation.rs:21:15
+ |
+LL | while not the_worst {
+ | ----^^^^^^^^^
+ | |
+ | help: use `!` to perform logical negation
+
+error: unexpected `println` after identifier
+ --> $DIR/issue-46836-identifier-not-instead-of-negation.rs:30:9
+ |
+LL | if not // lack of braces is [sic]
+ | ----- help: use `!` to perform logical negation
+LL | println!("Then when?");
+ | ^^^^^^^
+
+error: expected `{`, found `;`
+ --> $DIR/issue-46836-identifier-not-instead-of-negation.rs:30:31
+ |
+LL | if not // lack of braces is [sic]
+ | -- this `if` statement has a condition, but no block
+LL | println!("Then when?");
+ | ^
+
+error: unexpected `2` after identifier
+ --> $DIR/issue-46836-identifier-not-instead-of-negation.rs:36:24
+ |
+LL | let resource = not 2;
+ | ----^
+ | |
+ | help: use `!` to perform logical negation
+
+error: unexpected `be_smothered_out_before` after identifier
+ --> $DIR/issue-46836-identifier-not-instead-of-negation.rs:42:27
+ |
+LL | let young_souls = not be_smothered_out_before;
+ | ----^^^^^^^^^^^^^^^^^^^^^^^
+ | |
+ | help: use `!` to perform logical negation
+
+error: aborting due to 6 previous errors
+
projects / rust.git / commitdiff