NQuads Parser is not working properly

[sumutcan]

rdflib-js produces blank nodes with underscore after : character. When the jsonld.js library tries to parse it with rdf-canonize the QUAD regex does not match with such a blank node and throws an error.

following snippet in NQuads.js does not parse the blank node: _:_g_L15C515

      // parse quad

      const match = line.match(REGEX.quad);

      if(match === null) {
        throw new Error('N-Quads parse error on line ' + lineNumber + '.');
      }

Quoting from NQuads specification:

RDF blank nodes in N-Quads are expressed as _: followed by a blank node label which is a series of name characters. The characters in the label are built upon PN_CHARS_BASE, liberalized as follows:
The characters _ and digits may appear anywhere in a blank node label.
The character . may appear anywhere except the first or last character.
The characters -, U+00B7, U+0300 to U+036F and U+203F to U+2040 are permitted anywhere except the first character.

Changing the regex in NQuads.js to (_:(?:[A-Za-z0-9_]+)) should solve the issue.

[davidlehn]

This was reported before but apparently hasn't yet been addressed:
digitalbazaar/jsonld.js#158

[davidlehn]

New regex should (mostly) match the blank node grammer from the turtle spec now:
90455df