How to define a rule to match with a pattern multiple times in PEG.js?

Question

I'm trying to parse a file where the pattern might be seen multiple times:

G04 hello world*
G04 foo bar*

The corresponding PEG.js grammar is:

Comment
  = "G04" _ content:String* _ EOL
  {
    return content
  }

_ "whitespace"
  = [ \t\n\r]*

String
  = value:[a-zA-Z0-9.(): _-]+
  {
    return value.join('') 
  }

EOL
  = [*] _

However, I'm getting the following error:

Line 2, column 1: Expected end of input but "G" found.

How do I make this Comment rule to match multiple times?

score 1 · Accepted Answer · answered Jan 31 '20 at 19:15

You should just be able to add a new start rule that matches multiple Comments:

Comments
  = Comment+

Comment
  = "G04" _ content:String* _ EOL
  {
    return content
  }

_ "whitespace"
  = [ \t\n\r]*

String
  = value:[a-zA-Z0-9.(): _-]+
  {
    return value.join('') 
  }

EOL
  = [*] _

Output:

[
   [
      "hello world"
   ],
   [
      "foo bar"
   ]
]

How to define a rule to match with a pattern multiple times in PEG.js?

1 Answers1