ListOf handling newline characters

[drush]

Trying to figure out the syntax to allow lists to have support for multiple types of delimiters, ie comma and newline

one,two,three

one, two
three

one
two
three

This should fail (space is not a delimiter):

one two

Best code so far:

Table {
  Columns (a list of columns)
   = ListOf<ident, delim>
​
  delim  (an identifier)
    = "\n" | ","
    
  ident  (an identifier)
    = letter alnum*
}

But this doesn't recognize the newlines at all. Changing the ident to Ident handles the newlines properly but doesn't reject the last case - it treats both words and the space as a single ident. It should error.

[pdubroy]

Hi Darren,

If your language has significant newlines, it probably makes sense to redefine the space rule. That will change the behavior of the implicit space skipping. The built-in definition includes any character from \x00 up to and including \x20 (space). E.g., you might want to define the space rule like this:

space := ~"\n" "\x00".."\x20"

Alternatively you could use listOf rather than ListOf, which would eliminate implicit space skipping, so you'd need to do it yourself. E.g., something like this may work:

Columns = listOf<ident, delim>
delim = spaceNoNL* ("\n" | ",")
spaceNoNL = ~"\n" "\x00".."\x20"

Does that help?

[drush]

This got us on the right track. Thanks much!