| … | |
… | |
| 103 | |
103 | |
| 104 | =over 4 |
104 | =over 4 |
| 105 | |
105 | |
| 106 | =item $json_text = to_json $perl_scalar |
106 | =item $json_text = to_json $perl_scalar |
| 107 | |
107 | |
| 108 | Converts the given Perl data structure (a simple scalar or a reference to |
108 | Converts the given Perl data structure to a UTF-8 encoded, binary string |
| 109 | a hash or array) to a UTF-8 encoded, binary string (that is, the string contains |
109 | (that is, the string contains octets only). Croaks on error. |
| 110 | octets only). Croaks on error. |
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| 111 | |
110 | |
| 112 | This function call is functionally identical to: |
111 | This function call is functionally identical to: |
| 113 | |
112 | |
| 114 | $json_text = JSON::XS->new->utf8->encode ($perl_scalar) |
113 | $json_text = JSON::XS->new->utf8->encode ($perl_scalar) |
| 115 | |
114 | |
| 116 | except being faster. |
115 | except being faster. |
| 117 | |
116 | |
| 118 | =item $perl_scalar = from_json $json_text |
117 | =item $perl_scalar = from_json $json_text |
| 119 | |
118 | |
| 120 | The opposite of C<to_json>: expects an UTF-8 (binary) string and tries to |
119 | The opposite of C<to_json>: expects an UTF-8 (binary) string and tries |
| 121 | parse that as an UTF-8 encoded JSON text, returning the resulting simple |
120 | to parse that as an UTF-8 encoded JSON text, returning the resulting |
| 122 | scalar or reference. Croaks on error. |
121 | reference. Croaks on error. |
| 123 | |
122 | |
| 124 | This function call is functionally identical to: |
123 | This function call is functionally identical to: |
| 125 | |
124 | |
| 126 | $perl_scalar = JSON::XS->new->utf8->decode ($json_text) |
125 | $perl_scalar = JSON::XS->new->utf8->decode ($json_text) |
| 127 | |
126 | |
| … | |
… | |
| 135 | |
134 | |
| 136 | See MAPPING, below, for more information on how JSON values are mapped to |
135 | See MAPPING, below, for more information on how JSON values are mapped to |
| 137 | Perl. |
136 | Perl. |
| 138 | |
137 | |
| 139 | =back |
138 | =back |
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139 | |
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140 | |
|
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141 | =head1 A FEW NOTES ON UNICODE AND PERL |
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142 | |
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143 | Since this often leads to confusion, here are a few very clear words on |
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144 | how Unicode works in Perl, modulo bugs. |
|
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145 | |
|
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146 | =over 4 |
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147 | |
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148 | =item 1. Perl strings can store characters with ordinal values > 255. |
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149 | |
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150 | This enables you to store unicode characters as single characters in a |
|
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151 | Perl string - very natural. |
|
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152 | |
|
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153 | =item 2. Perl does I<not> associate an encoding with your strings. |
|
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154 | |
|
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155 | Unless you force it to, e.g. when matching it against a regex, or printing |
|
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156 | the scalar to a file, in which case Perl either interprets your string as |
|
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157 | locale-encoded text, octets/binary, or as Unicode, depending on various |
|
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158 | settings. In no case is an encoding stored together with your data, it is |
|
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159 | I<use> that decides encoding, not any magical metadata. |
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160 | |
|
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161 | =item 3. The internal utf-8 flag has no meaning with regards to the |
|
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162 | encoding of your string. |
|
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163 | |
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164 | Just ignore that flag unless you debug a Perl bug, a module written in |
|
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165 | XS or want to dive into the internals of perl. Otherwise it will only |
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166 | confuse you, as, despite the name, it says nothing about how your string |
|
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167 | is encoded. You can have unicode strings with that flag set, with that |
|
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168 | flag clear, and you can have binary data with that flag set and that flag |
|
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169 | clear. Other possibilities exist, too. |
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170 | |
|
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171 | If you didn't know about that flag, just the better, pretend it doesn't |
|
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172 | exist. |
|
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173 | |
|
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174 | =item 4. A "Unicode String" is simply a string where each character can be |
|
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175 | validly interpreted as a Unicode codepoint. |
|
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176 | |
|
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177 | If you have UTF-8 encoded data, it is no longer a Unicode string, but a |
|
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178 | Unicode string encoded in UTF-8, giving you a binary string. |
|
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179 | |
|
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180 | =item 5. A string containing "high" (> 255) character values is I<not> a UTF-8 string. |
|
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181 | |
|
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182 | Its a fact. Learn to live with it. |
|
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183 | |
|
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184 | =back |
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185 | |
|
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186 | I hope this helps :) |
| 140 | |
187 | |
| 141 | |
188 | |
| 142 | =head1 OBJECT-ORIENTED INTERFACE |
189 | =head1 OBJECT-ORIENTED INTERFACE |
| 143 | |
190 | |
| 144 | The object oriented interface lets you configure your own encoding or |
191 | The object oriented interface lets you configure your own encoding or |
