LibTextCodec: Add a function to convert encodings to standardized names

https://encoding.spec.whatwg.org/#names-and-labels

2 files changed, 101 insertions, 1 deletions

diff --git a/Libraries/LibTextCodec/Decoder.cpp b/Libraries/LibTextCodec/Decoder.cpp
index c4e3c94dd9..3ce651ade5 100644
--- a/Libraries/LibTextCodec/Decoder.cpp
+++ b/Libraries/LibTextCodec/Decoder.cpp
@@ -48,13 +48,111 @@ static UTF8Decoder& utf8_decoder()
 
 Decoder* decoder_for(const String& encoding)
 {
-    if (encoding.equals_ignoring_case("iso-8859-1"))
+    ASSERT(is_standardized_encoding(encoding));
+    if (encoding.equals_ignoring_case("windows-1252"))
         return &latin1_decoder();
     if (encoding.equals_ignoring_case("utf-8"))
         return &utf8_decoder();
+    dbg() << "TextCodec: No decoder implemented for encoding '" << encoding << "'";
     return nullptr;
 }
 
+// https://encoding.spec.whatwg.org/#concept-encoding-get
+String get_standardized_encoding(const String& encoding)
+{
+    String trimmed_lowercase_encoding = encoding.trim_whitespace().to_lowercase();
+
+    if (trimmed_lowercase_encoding.is_one_of("unicode-1-1-utf-8", "unicode11utf8", "unicode20utf8", "utf-8", "utf8", "x-unicode20utf8"))
+        return "UTF-8";
+    if (trimmed_lowercase_encoding.is_one_of("866", "cp866", "csibm866", "ibm666"))
+        return "IBM666";
+    if (trimmed_lowercase_encoding.is_one_of("csisolatin2", "iso-8859-2", "iso-ir-101", "iso8859-2", "iso88592", "iso_8859-2", "iso_8859-2:1987", "l2", "latin2"))
+        return "ISO-8859-2";
+    if (trimmed_lowercase_encoding.is_one_of("csisolatin3", "iso-8859-3", "iso-ir-109", "iso8859-3", "iso88593", "iso_8859-3", "iso_8859-3:1988", "l3", "latin3"))
+        return "ISO-8859-3";
+    if (trimmed_lowercase_encoding.is_one_of("csisolatin4", "iso-8859-4", "iso-ir-110", "iso8859-4", "iso88594", "iso_8859-4", "iso_8859-4:1989", "l4", "latin4"))
+        return "ISO-8859-4";
+    if (trimmed_lowercase_encoding.is_one_of("csisolatincyrillic", "cyrillic", "iso-8859-5", "iso-ir-144", "iso8859-5", "iso88595", "iso_8859-5", "iso_8859-5:1988"))
+        return "ISO-8859-5";
+    if (trimmed_lowercase_encoding.is_one_of("arabic", "asmo-708", "csiso88596e", "csiso88596i", "csisolatinarabic", "ecma-114", "iso-8859-6", "iso-8859-6-e", "iso-8859-6-i", "iso-ir-127", "iso8859-6", "iso88596", "iso_8859-6", "iso_8859-6:1987"))
+        return "ISO-8859-6";
+    if (trimmed_lowercase_encoding.is_one_of("csisolatingreek", "ecma-118", "elot_928", "greek", "greek8", "iso-8859-7", "iso-ir-126", "iso8859-7", "iso88597", "iso_8859-7", "iso_8859-7:1987", "sun_eu_greek"))
+        return "ISO-8859-7";
+    if (trimmed_lowercase_encoding.is_one_of("csiso88598e", "csisolatinhebrew", "hebrew", "iso-8859-8", "iso-8859-8-e", "iso-ir-138", "iso8859-8", "iso88598", "iso_8859-8", "iso_8859-8:1988", "visual"))
+        return "ISO-8859-8";
+    if (trimmed_lowercase_encoding.is_one_of("csiso88598i", "iso-8859-8-i", "logical"))
+        return "ISO-8859-8-I";
+    if (trimmed_lowercase_encoding.is_one_of("csisolatin6", "iso8859-10", "iso-ir-157", "iso8859-10", "iso885910", "l6", "latin6"))
+        return "ISO-8859-10";
+    if (trimmed_lowercase_encoding.is_one_of("iso-8859-13", "iso8859-13", "iso885913"))
+        return "ISO-8859-13";
+    if (trimmed_lowercase_encoding.is_one_of("iso-8859-14", "iso8859-14", "iso885914"))
+        return "ISO-8859-14";
+    if (trimmed_lowercase_encoding.is_one_of("csisolatin9", "iso-8859-15", "iso8859-15", "iso885915", "iso_8859-15", "l9"))
+        return "ISO-8859-15";
+    if (trimmed_lowercase_encoding == "iso-8859-16")
+        return "ISO-8859-16";
+    if (trimmed_lowercase_encoding.is_one_of("cskoi8r", "koi", "koi8", "koi8-r", "koi8_r"))
+        return "KOI8-R";
+    if (trimmed_lowercase_encoding.is_one_of("koi8-ru", "koi8-u"))
+        return "KOI8-U";
+    if (trimmed_lowercase_encoding.is_one_of("csmacintosh", "mac", "macintosh", "x-mac-roman"))
+        return "macintosh";
+    if (trimmed_lowercase_encoding.is_one_of("dos-874", "iso-8859-11", "iso8859-11", "iso885911", "tis-620", "windows-874"))
+        return "windows-874";
+    if (trimmed_lowercase_encoding.is_one_of("cp1250", "windows-1250", "x-cp1250"))
+        return "windows-1250";
+    if (trimmed_lowercase_encoding.is_one_of("cp1251", "windows-1251", "x-cp1251"))
+        return "windows-1251";
+    if (trimmed_lowercase_encoding.is_one_of("ansi_x3.4-1968", "ascii", "cp1252", "cp819", "csisolatin1", "ibm819", "iso-8859-1", "iso-ir-100", "iso8859-1", "iso88591", "iso_8859-1", "iso_8859-1:1987", "l1", "latin1", "us-ascii", "windows-1252", "x-cp1252"))
+        return "windows-1252";
+    if (trimmed_lowercase_encoding.is_one_of("cp1253", "windows-1253", "x-cp1253"))
+        return "windows-1253";
+    if (trimmed_lowercase_encoding.is_one_of("cp1254", "csisolatin5", "iso-8859-9", "iso-ir-148", "iso-8859-9", "iso-88599", "iso_8859-9", "iso_8859-9:1989", "l5", "latin5", "windows-1254", "x-cp1254"))
+        return "windows-1254";
+    if (trimmed_lowercase_encoding.is_one_of("cp1255", "windows-1255", "x-cp1255"))
+        return "windows-1255";
+    if (trimmed_lowercase_encoding.is_one_of("cp1256", "windows-1256", "x-cp1256"))
+        return "windows-1256";
+    if (trimmed_lowercase_encoding.is_one_of("cp1257", "windows-1257", "x-cp1257"))
+        return "windows-1257";
+    if (trimmed_lowercase_encoding.is_one_of("cp1258", "windows-1258", "x-cp1258"))
+        return "windows-1258";
+    if (trimmed_lowercase_encoding.is_one_of("x-mac-cyrillic", "x-mac-ukrainian"))
+        return "x-mac-cyrillic";
+    if (trimmed_lowercase_encoding.is_one_of("chinese", "csgb2312", "csiso58gb231280", "gb2312", "gb_2312", "gb_2312-80", "gbk", "iso-ir-58", "x-gbk"))
+        return "GBK";
+    if (trimmed_lowercase_encoding == "gb18030")
+        return "gb18030";
+    if (trimmed_lowercase_encoding.is_one_of("big5", "big5-hkscs", "cn-big5", "csbig5", "x-x-big5"))
+        return "Big5";
+    if (trimmed_lowercase_encoding.is_one_of("cseucpkdfmtjapanese", "euc-jp", "x-euc-jp"))
+        return "EUC-JP";
+    if (trimmed_lowercase_encoding.is_one_of("csiso2022jp", "iso-2022-jp"))
+        return "ISO-2022-JP";
+    if (trimmed_lowercase_encoding.is_one_of("csshiftjis", "ms932", "ms_kanji", "shift-jis", "shift_jis", "sjis", "windows-31j", "x-sjis"))
+        return "Shift_JIS";
+    if (trimmed_lowercase_encoding.is_one_of("cseuckr", "csksc56011987", "euc-kr", "iso-ir-149", "korean", "ks_c_5601-1987", "ks_c_5601-1989", "ksc5601", "ksc_5601", "windows-949"))
+        return "EUC-KR";
+    if (trimmed_lowercase_encoding.is_one_of("csiso2022kr", "hz-gb-2312", "iso-2022-cn", "iso-2022-cn-ext", "iso-2022-kr", "replacement"))
+        return "replacement";
+    if (trimmed_lowercase_encoding.is_one_of("unicodefffe", "utf-16be"))
+        return "UTF-16BE";
+    if (trimmed_lowercase_encoding.is_one_of("csunicode", "iso-10646-ucs-2", "ucs-2", "unicode", "unicodefeff", "utf-16", "utf-16le"))
+        return "UTF-16LE";
+    if (trimmed_lowercase_encoding == "x-user-defined")
+        return "x-user-defined";
+
+    dbg() << "TextCodec: Unrecognized encoding: " << encoding;
+    return {};
+}
+
+bool is_standardized_encoding(const String& encoding)
+{
+    auto lowercase_encoding = encoding.to_lowercase();
+    return lowercase_encoding.is_one_of("utf-8", "ibm666", "iso-8859-2", "iso-8859-3", "iso-8859-4", "iso-8859-5", "iso-8859-6", "iso-8859-7", "iso-8859-8", "iso-8859-8-I", "iso-8859-10", "iso-8859-13", "iso-8859-14", "iso-8859-15", "iso-8859-16", "koi8-r", "koi8-u", "macintosh", "windows-874", "windows-1250", "windows-1251", "windows-1252", "windows-1253", "windows-1254", "windows-1255", "windows-1256", "windows-1257", "windows-1258", "x-mac-cyrillic", "gbk", "gb18030", "big5", "euc-jp", "iso-2022-JP", "shift_jis", "euc-kr", "replacement", "utf-16be", "utf-16le", "x-user-defined");
+}
+
 String UTF8Decoder::to_utf8(const StringView& input)
 {
     return input;
diff --git a/Libraries/LibTextCodec/Decoder.h b/Libraries/LibTextCodec/Decoder.h
index 419617f49c..1f476c42df 100644
--- a/Libraries/LibTextCodec/Decoder.h
+++ b/Libraries/LibTextCodec/Decoder.h
@@ -46,5 +46,7 @@ public:
 };
 
 Decoder* decoder_for(const String& encoding);
+String get_standardized_encoding(const String& encoding);
+bool is_standardized_encoding(const String& encoding);
 
 }