From f14d007ee4f4b69cdb3880db49608b432bea8352 Mon Sep 17 00:00:00 2001 From: David Wood Date: Wed, 23 Jan 2019 16:42:23 +0100 Subject: Add suggestion for incorrect field syntax. This commit adds a suggestion when a `=` character is used when specifying the value of a field in a struct constructor incorrectly instead of a `:` character. --- src/libsyntax/parse/parser.rs | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) (limited to 'src/libsyntax/parse') diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index 09ea0995253..b9c602550e3 100644 --- a/src/libsyntax/parse/parser.rs +++ b/src/libsyntax/parse/parser.rs @@ -2263,8 +2263,24 @@ impl<'a> Parser<'a> { let lo = self.span; // Check if a colon exists one ahead. This means we're parsing a fieldname. - let (fieldname, expr, is_shorthand) = if self.look_ahead(1, |t| t == &token::Colon) { + let (fieldname, expr, is_shorthand) = if self.look_ahead(1, |t| { + t == &token::Colon || t == &token::Eq + }) { let fieldname = self.parse_field_name()?; + + // Check for an equals token. This means the source incorrectly attempts to + // initialize a field with an eq rather than a colon. + if self.token == token::Eq { + self.diagnostic() + .struct_span_err(self.span, "expected `:`, found `=`") + .span_suggestion_with_applicability( + fieldname.span.shrink_to_hi().to(self.span), + "replace equals symbol with a colon", + ":".to_string(), + Applicability::MachineApplicable, + ) + .emit(); + } self.bump(); // `:` (fieldname, self.parse_expr()?, false) } else { -- cgit 1.4.1-3-g733a5