/// Parses an expression enclosed in parenthesis.
Parses an expression enclosed in parenthesis.
Parses an expression enclosed in parenthesis .
fn parse_paren_expr(&mut self) -> Result<Expr, &'static str> {
        match self.current()? {
            LParen => (),
            _ => return Err("Expected '(' character at start of parenthesized expression."),
        }
        self.advance()?;
        let expr = self.parse_expr()?;
        match self.current()? {
            RParen => (),
            _ => return Err("Expected ')' character at end of parenthesized expression."),
        }
        self.advance();
        Ok(expr)
    }
fn parse_paren_expr ( & mut self ) -> Result < Expr , & ' static str > { match self . current ( ) ? { LParen => ( ) , _ => return Err ( " " ) , } self . advance ( ) ? ; let expr = self . parse_expr ( ) ? ; match self . current ( ) ? { RParen => ( ) , _ => return Err ( " " ) , } self . advance ( ) ; Ok ( expr ) }
Parses an expression enclosed in parenthesis.
Parses an expression enclosed in parenthesis .
&mut self