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我寫在斯卡拉解析器和被困在這一點上: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}
我的問題是,當涉及到一個「表達」的分析器不始終以正確的方式。就像它的funk(x,y)
它試圖像解析一個變量螞蟻一樣不像函數。
有什麼想法?
更改'表達式'中的順序。嘗試功能放在變量前面。 – Rumoku
我覺得|||操作能解決嗎? – mstranne
這與[tag:java]有什麼關係? –