Add support for the /u flag (RegExp.prototype.unicode)

[mathiasbynens]

https://people.mozilla.org/~jorendorff/es6-draft.html#sec-get-regexp.prototype.unicode

Contrary to #8, this does affect parsing; based on whether or not the u flag was set, different parsing logic applies.

[mathiasbynens]

Note: the current support for Unicode code point escapes should only be enabled when the u flag is set, as per the spec.

[mathiasbynens]

Bug: regjsparser.parse('\uD834\uDF06', 'u') says type: escape but it should be type: character.

[jviereck]

Just tried with the current version and now get this output:

{
    "type": "alternative",
    "body": [
        {
            "type": "value",
            "kind": "unicode",
            "codePoint": 119558,
            "range": [
                0,
                12
            ],
            "raw": "\\uD834\\uDF06"
        }
    ],
    "range": [
        0,
        12
    ],
    "raw": "\\uD834\\uDF06",
    "lastMatchIdx": 0
}

Therefore, closing this issue.

[mathiasbynens]

"kind": "unicode"

Wait, what? I thought we renamed that?

[jviereck]

You are right, I and it is renamed - I was not on the master branch when testing this. From master, the output looks (correctly) like this:

{
    "type": "alternative",
    "body": [
        {
            "type": "value",
            "kind": "unicodeCodePointEscape",
            "codePoint": 119558,
            "range": [
                0,
                12
            ],
            "raw": "\\uD834\\uDF06"
        }
    ],
    "range": [
        0,
        12
    ],
    "raw": "\\uD834\\uDF06",
    "lastMatchIdx": 0
}

[mathiasbynens]

Your example still says it’s an escape sequence (because the CLI is used and it considers the \ as a string containing a slash, i.e. \\) but you’re right in that the output is now correct in this case:

> regjsparser.parse('\uD834\uDF06', 'u')
{ type: 'alternative',
  body:
   [ { type: 'value',
       kind: 'symbol',
       codePoint: 119558,
       range: [Object],
       raw: '\uD834\uDF06' } ],
  range: [ 0, 2 ],
  raw: '\uD834\uDF06',
  lastMatchIdx: 0 }