用PEG.js忽略空格

Question

我想用我的语法忽略空格和新行,因此它们在PEG.js输出中缺失.此外,括号内的文字应该在新数组中返回.

语法

start
  = 'a'? sep+ ('cat'/'dog') sep* '(' sep* stmt_list sep* ')'

stmt_list
  = exp: [a-zA-Z]+ { return new Array(exp.join('')) }

sep
  = [' '\t\r\n]

测试用例

a dog( Harry )

产量

[
   "a",
   [
      " "
   ],
   "dog",
   [],
   "(",
   [
      " "
   ],
   [
       "Harry"
   ],
   [
      " "
   ],
   ")"
]

我想要的输出

[
   "a",
   "dog",
   [
      "Harry"
   ]
]

Answer 1

你必须更多地使用更多的"非终端"分解语法(不确定这是否是你在PEG中所称的那些):

start
  = article animal stmt_list

article
  = article:'a'? __ { return article; }

animal
  = animal:('cat'/'dog') _ { return animal; }

stmt_list
  = '(' _ exp:[a-zA-Z]+ _ ')' { return [ exp.join('') ]; }

// optional whitespace
_  = [ \t\r\n]*

// mandatory whitespace
__ = [ \t\r\n]+

谢谢你提出这个问题!

编辑: 为了提高可读性,有两个产品:_和__