Method apply2

core/src/parser.rs:219–231

(
            exprs: &mut Vec<Expr>,
            pos: LineCol,
            f: fn(Box<BinaryOpSpan>) -> Expr,
        )

        }

        fn apply2(
            exprs: &mut Vec<Expr>,
            pos: LineCol,
            f: fn(Box<BinaryOpSpan>) -> Expr,
        ) -> Result<()> {
            if exprs.len() < 2 {
                return Err(Error::Bad(pos, "Not enough values to apply operator".to_owned()));
            }
            let rhs = exprs.pop().unwrap();
            let lhs = exprs.pop().unwrap();
            exprs.push(f(Box::from(BinaryOpSpan { lhs, rhs, pos })));
            Ok(())
        }

        match self.op {
            ExprOp::Add => apply2(exprs, self.pos, Expr::Add),