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我写在斯卡拉解析器和被困在这一点上:解析斯卡拉/ Java的
private def expression : Parser[Expression] = cond | variable | integer | liste | function
private def cond : Parser[Expression] = "if" ~ predicate ~ "then" ~ expression ~ "else" ~ expression ^^ {case _~i~_~t~_~el => Cond(i,t,el)}
private def predicate: Parser[Predicate] = identifier ~ "?" ~ "(" ~ repsep(expression, ",") ~ ")" ^^{case n~_~_~el~_ => Predicate(n,el)}
private def function: Parser[Expression] = identifier ~ "(" ~ repsep(expression, ",") ~ ")" ^^{case n~_~el~_ => Function(n,el)}
private def liste: Parser[Expression] = "[" ~ repsep(expression, ",") ~ "]" ^^ {case _~ls~_ => Liste(ls)}
private def variable: Parser[Expression] = identifier ^^ {case v => Variable(v)}
def identifier: Parser[String] = """[a-zA-Z0-9]+""".r ^^ { _.toString }
def integer: Parser[Integer] = num ^^ { case i => Integer(i)}
def num: Parser[String] = """(-?\d*)""".r ^^ {_.toString}
我的问题是,当涉及到一个“表达”的分析器不始终以正确的方式。就像它的funk(x,y)
它试图像解析一个变量蚂蚁一样不像函数。
有什么想法?
更改'表达式'中的顺序。尝试功能放在变量前面。 – Rumoku
我觉得|||操作能解决吗? – mstranne
这与[tag:java]有什么关系? –