+ - identifier: "\\b(placeholder|style|alt|bgcolor|height|href|id|(aria|data)\\-.+|label|longdesc|name|on(click|focus|load|mouseover)|size|span|src|target|type|value|width|class|charset|content|rel|integrity|crossorigin|for|onsubmit|lang|role)\\b"
+ - special: "\\b(required)\\b"
+ # Match double-quote strings
+ - constant.string:
+ start: "\""
+ end: "\""
+ skip: "\\\\."
+ rules:
+ - constant.specialChar: "\\\\."
+ - constant.string.url: "((ftp(s)?|http(s)?|git|chrome)://[^\\s]+)"
+ # Match single-quote strings
+ - constant.string:
+ start: "'"
+ end: "'"
+ skip: "\\\\."
+ rules:
+ - constant.specialChar: "\\\\."
+ - constant.string.url: "((ftp(s)?|http(s)?|git|chrome)://[^\\s]+)"
+ # Highlight the equals and any colon between words
+ - symbol: "\\b(=|:\\b)"