使用https://github.com/JetBrains/Grammar-Kit如何在没有左递归的情况下重写语法?
grammar ::= exprs
exprs::= (sum_expr (';')?)*
private sum_expr::= sum_expr_infix | sum_expr_prefix
sum_expr_infix ::= number sum_expr_prefix
left sum_expr_prefix::= op_plus number
private op_plus ::= '+'
number ::= float | integer
float ::= digit+ '.' digit*
integer ::= digit+
private digit ::=('0'|'1'|'2'|'3'|'4'|'5'|'6'|'7'|'8'|'9')
样本输入:
10+20+30.0;
10+20+30.0
答案应维护节点包含 2/3 个子节点的解析树属性: