escape consecutive unpaired surrogates (#2576)

fixes #2569
2017-12-11 01:15:44 +08:00
parent bf000beae7
commit 93f3b2b114
3 changed files with 29 additions and 5 deletions
--- a/lib/parse.js
+++ b/lib/parse.js
@@ -132,6 +132,18 @@ function is_letter(code) {
        || (code >= 0xaa && UNICODE.letter.test(String.fromCharCode(code)));
 };

+function is_surrogate_pair_head(code) {
+    if (typeof code == "string")
+        code = code.charCodeAt(0);
+    return code >= 0xd800 && code <= 0xdbff;
+}
+
+function is_surrogate_pair_tail(code) {
+    if (typeof code == "string")
+        code = code.charCodeAt(0);
+    return code >= 0xdc00 && code <= 0xdfff;
+}
+
 function is_digit(code) {
    return code >= 48 && code <= 57;
 };