| … | |
… | |
| 1133 | as UTF-8, ISO-8859-1, ASCII, KOI8-R or most about any character set and |
1133 | as UTF-8, ISO-8859-1, ASCII, KOI8-R or most about any character set and |
| 1134 | 8-bit-encoding, and still get the same data structure back. This is useful |
1134 | 8-bit-encoding, and still get the same data structure back. This is useful |
| 1135 | when your channel for JSON transfer is not 8-bit clean or the encoding |
1135 | when your channel for JSON transfer is not 8-bit clean or the encoding |
| 1136 | might be mangled in between (e.g. in mail), and works because ASCII is a |
1136 | might be mangled in between (e.g. in mail), and works because ASCII is a |
| 1137 | proper subset of most 8-bit and multibyte encodings in use in the world. |
1137 | proper subset of most 8-bit and multibyte encodings in use in the world. |
| 1138 | |
|
|
| 1139 | =back |
|
|
| 1140 | |
|
|
| 1141 | |
|
|
| 1142 | =head1 COMPARISON |
|
|
| 1143 | |
|
|
| 1144 | As already mentioned, this module was created because none of the existing |
|
|
| 1145 | JSON modules could be made to work correctly. First I will describe the |
|
|
| 1146 | problems (or pleasures) I encountered with various existing JSON modules, |
|
|
| 1147 | followed by some benchmark values. JSON::XS was designed not to suffer |
|
|
| 1148 | from any of these problems or limitations. |
|
|
| 1149 | |
|
|
| 1150 | =over 4 |
|
|
| 1151 | |
|
|
| 1152 | =item JSON 2.xx |
|
|
| 1153 | |
|
|
| 1154 | A marvellous piece of engineering, this module either uses JSON::XS |
|
|
| 1155 | directly when available (so will be 100% compatible with it, including |
|
|
| 1156 | speed), or it uses JSON::PP, which is basically JSON::XS translated to |
|
|
| 1157 | Pure Perl, which should be 100% compatible with JSON::XS, just a bit |
|
|
| 1158 | slower. |
|
|
| 1159 | |
|
|
| 1160 | You cannot really lose by using this module, especially as it tries very |
|
|
| 1161 | hard to work even with ancient Perl versions, while JSON::XS does not. |
|
|
| 1162 | |
|
|
| 1163 | =item JSON 1.07 |
|
|
| 1164 | |
|
|
| 1165 | Slow (but very portable, as it is written in pure Perl). |
|
|
| 1166 | |
|
|
| 1167 | Undocumented/buggy Unicode handling (how JSON handles Unicode values is |
|
|
| 1168 | undocumented. One can get far by feeding it Unicode strings and doing |
|
|
| 1169 | en-/decoding oneself, but Unicode escapes are not working properly). |
|
|
| 1170 | |
|
|
| 1171 | No round-tripping (strings get clobbered if they look like numbers, e.g. |
|
|
| 1172 | the string C<2.0> will encode to C<2.0> instead of C<"2.0">, and that will |
|
|
| 1173 | decode into the number 2. |
|
|
| 1174 | |
|
|
| 1175 | =item JSON::PC 0.01 |
|
|
| 1176 | |
|
|
| 1177 | Very fast. |
|
|
| 1178 | |
|
|
| 1179 | Undocumented/buggy Unicode handling. |
|
|
| 1180 | |
|
|
| 1181 | No round-tripping. |
|
|
| 1182 | |
|
|
| 1183 | Has problems handling many Perl values (e.g. regex results and other magic |
|
|
| 1184 | values will make it croak). |
|
|
| 1185 | |
|
|
| 1186 | Does not even generate valid JSON (C<{1,2}> gets converted to C<{1:2}> |
|
|
| 1187 | which is not a valid JSON text. |
|
|
| 1188 | |
|
|
| 1189 | Unmaintained (maintainer unresponsive for many months, bugs are not |
|
|
| 1190 | getting fixed). |
|
|
| 1191 | |
|
|
| 1192 | =item JSON::Syck 0.21 |
|
|
| 1193 | |
|
|
| 1194 | Very buggy (often crashes). |
|
|
| 1195 | |
|
|
| 1196 | Very inflexible (no human-readable format supported, format pretty much |
|
|
| 1197 | undocumented. I need at least a format for easy reading by humans and a |
|
|
| 1198 | single-line compact format for use in a protocol, and preferably a way to |
|
|
| 1199 | generate ASCII-only JSON texts). |
|
|
| 1200 | |
|
|
| 1201 | Completely broken (and confusingly documented) Unicode handling (Unicode |
|
|
| 1202 | escapes are not working properly, you need to set ImplicitUnicode to |
|
|
| 1203 | I<different> values on en- and decoding to get symmetric behaviour). |
|
|
| 1204 | |
|
|
| 1205 | No round-tripping (simple cases work, but this depends on whether the scalar |
|
|
| 1206 | value was used in a numeric context or not). |
|
|
| 1207 | |
|
|
| 1208 | Dumping hashes may skip hash values depending on iterator state. |
|
|
| 1209 | |
|
|
| 1210 | Unmaintained (maintainer unresponsive for many months, bugs are not |
|
|
| 1211 | getting fixed). |
|
|
| 1212 | |
|
|
| 1213 | Does not check input for validity (i.e. will accept non-JSON input and |
|
|
| 1214 | return "something" instead of raising an exception. This is a security |
|
|
| 1215 | issue: imagine two banks transferring money between each other using |
|
|
| 1216 | JSON. One bank might parse a given non-JSON request and deduct money, |
|
|
| 1217 | while the other might reject the transaction with a syntax error. While a |
|
|
| 1218 | good protocol will at least recover, that is extra unnecessary work and |
|
|
| 1219 | the transaction will still not succeed). |
|
|
| 1220 | |
|
|
| 1221 | =item JSON::DWIW 0.04 |
|
|
| 1222 | |
|
|
| 1223 | Very fast. Very natural. Very nice. |
|
|
| 1224 | |
|
|
| 1225 | Undocumented Unicode handling (but the best of the pack. Unicode escapes |
|
|
| 1226 | still don't get parsed properly). |
|
|
| 1227 | |
|
|
| 1228 | Very inflexible. |
|
|
| 1229 | |
|
|
| 1230 | No round-tripping. |
|
|
| 1231 | |
|
|
| 1232 | Does not generate valid JSON texts (key strings are often unquoted, empty keys |
|
|
| 1233 | result in nothing being output) |
|
|
| 1234 | |
|
|
| 1235 | Does not check input for validity. |
|
|
| 1236 | |
1138 | |
| 1237 | =back |
1139 | =back |
| 1238 | |
1140 | |
| 1239 | |
1141 | |
| 1240 | =head2 JSON and YAML |
1142 | =head2 JSON and YAML |
