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Implement field shorthands in struct literal expressions.

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This commit is contained in:
Eduard Burtescu 2016-10-27 03:15:13 +03:00
parent a5b6a9fa8a
commit 9908711e5e
15 changed files with 179 additions and 18 deletions
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29
src/libsyntax/parse/parser.rs
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@ -2007,17 +2007,30 @@ impl<'a> Parser<'a> {
}
}
/// Parse ident COLON expr
/// Parse ident (COLON expr)?
pub fn parse_field(&mut self) -> PResult<'a, Field> {
let lo = self.span.lo;
let i = self.parse_field_name()?;
let hi = self.prev_span.hi;
self.expect(&token::Colon)?;
let e = self.parse_expr()?;
let hi;
// 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 = self.parse_field_name()?;
self.bump();
hi = self.prev_span.hi;
(fieldname, self.parse_expr()?, false)
} else {
let fieldname = self.parse_ident()?;
hi = self.prev_span.hi;
// Mimic `x: x` for the `x` field shorthand.
let path = ast::Path::from_ident(mk_sp(lo, hi), fieldname);
(fieldname, self.mk_expr(lo, hi, ExprKind::Path(None, path), ThinVec::new()), true)
};
Ok(ast::Field {
ident: spanned(lo, hi, i),
span: mk_sp(lo, e.span.hi),
expr: e,
ident: spanned(lo, hi, fieldname),
span: mk_sp(lo, expr.span.hi),
expr: expr,
is_shorthand: is_shorthand,
})
}