[ViewVC] Diff of: cvs/JSON-XS/README

Comparing JSON-XS/README (file contents):
Revision 1.16 by root, Thu Jul 26 11:33:35 2007 UTC vs.
Revision 1.20 by root, Tue Nov 13 22:59:08 2007 UTC

 NAME
     JSON::XS - JSON serialising/deserialising, done correctly and fast
+    JSON::XS - 正しくて高速な JSON
+    シリアライザ/デシリアライザ
+    (http://fleur.hio.jp/perldoc/mix/lib/JSON/XS.html)
 SYNOPSIS
      use JSON::XS;
      # exported functions, they croak on error
     See MAPPING, below, on how JSON::XS maps perl values to JSON values and
     vice versa.
   FEATURES
-    * correct unicode handling
+    * correct Unicode handling
         This module knows how to handle Unicode, and even documents how and
         when it does so.
     * round-trip integrity
         When you serialise a perl data structure using only datatypes
     * simple to use
         This module has both a simple functional interface as well as an OO
         interface.
     * reasonably versatile output formats
-        You can choose between the most compact guarenteed single-line
+        You can choose between the most compact guaranteed single-line
         format possible (nice for simple line-based protocols), a pure-ascii
         format (for when your transport is not 8-bit clean, still supports
-        the whole unicode range), or a pretty-printed format (for when you
+        the whole Unicode range), or a pretty-printed format (for when you
         want to read that stuff). Or you can combine those features in
         whatever way you like.
 FUNCTIONAL INTERFACE
-    The following convinience methods are provided by this module. They are
+    The following convenience methods are provided by this module. They are
     exported by default:
     $json_text = to_json $perl_scalar
-        Converts the given Perl data structure (a simple scalar or a
+        Converts the given Perl data structure to a UTF-8 encoded, binary
-        reference to a hash or array) to a UTF-8 encoded, binary string
-        (that is, the string contains octets only). Croaks on error.
+        string (that is, the string contains octets only). Croaks on error.
         This function call is functionally identical to:
            $json_text = JSON::XS->new->utf8->encode ($perl_scalar)
         except being faster.
     $perl_scalar = from_json $json_text
         The opposite of "to_json": expects an UTF-8 (binary) string and
         tries to parse that as an UTF-8 encoded JSON text, returning the
-        resulting simple scalar or reference. Croaks on error.
+        resulting reference. Croaks on error.
         This function call is functionally identical to:
            $perl_scalar = JSON::XS->new->utf8->decode ($json_text)
         values in Perl.
         See MAPPING, below, for more information on how JSON values are
         mapped to Perl.
+A FEW NOTES ON UNICODE AND PERL
+    Since this often leads to confusion, here are a few very clear words on
+    how Unicode works in Perl, modulo bugs.
+    1. Perl strings can store characters with ordinal values > 255.
+        This enables you to store Unicode characters as single characters in
+        a Perl string - very natural.
+    2. Perl does *not* associate an encoding with your strings.
+        Unless you force it to, e.g. when matching it against a regex, or
+        printing the scalar to a file, in which case Perl either interprets
+        your string as locale-encoded text, octets/binary, or as Unicode,
+        depending on various settings. In no case is an encoding stored
+        together with your data, it is *use* that decides encoding, not any
+        magical metadata.
+    3. The internal utf-8 flag has no meaning with regards to the encoding
+    of your string.
+        Just ignore that flag unless you debug a Perl bug, a module written
+        in XS or want to dive into the internals of perl. Otherwise it will
+        only confuse you, as, despite the name, it says nothing about how
+        your string is encoded. You can have Unicode strings with that flag
+        set, with that flag clear, and you can have binary data with that
+        flag set and that flag clear. Other possibilities exist, too.
+        If you didn't know about that flag, just the better, pretend it
+        doesn't exist.
+    4. A "Unicode String" is simply a string where each character can be
+    validly interpreted as a Unicode codepoint.
+        If you have UTF-8 encoded data, it is no longer a Unicode string,
+        but a Unicode string encoded in UTF-8, giving you a binary string.
+    5. A string containing "high" (> 255) character values is *not* a UTF-8
+    string.
+        It's a fact. Learn to live with it.
+    I hope this helps :)
 OBJECT-ORIENTED INTERFACE
     The object oriented interface lets you configure your own encoding or
     decoding style, within the limits of supported formats.
     $json = new JSON::XS
            => {"a": [1, 2]}
     $json = $json->ascii ([$enable])
         If $enable is true (or missing), then the "encode" method will not
         generate characters outside the code range 0..127 (which is ASCII).
-        Any unicode characters outside that range will be escaped using
+        Any Unicode characters outside that range will be escaped using
         either a single \uXXXX (BMP characters) or a double \uHHHH\uLLLLL
         escape sequence, as per RFC4627. The resulting encoded JSON text can
-        be treated as a native unicode string, an ascii-encoded,
+        be treated as a native Unicode string, an ascii-encoded,
         latin1-encoded or UTF-8 encoded string, or any other superset of
         ASCII.
         If $enable is false, then the "encode" method will not escape
         Unicode characters unless required by the JSON syntax or other
     $json = $json->latin1 ([$enable])
         If $enable is true (or missing), then the "encode" method will
         encode the resulting JSON text as latin1 (or iso-8859-1), escaping
         any characters outside the code range 0..255. The resulting string
-        can be treated as a latin1-encoded JSON text or a native unicode
+        can be treated as a latin1-encoded JSON text or a native Unicode
         string. The "decode" method will not be affected in any way by this
-        flag, as "decode" by default expects unicode, which is a strict
+        flag, as "decode" by default expects Unicode, which is a strict
         superset of latin1.
         If $enable is false, then the "encode" method will not escape
         Unicode characters unless required by the JSON syntax or other
         flags.
         The main use for this flag is efficiently encoding binary data as
         JSON text, as most octets will not be escaped, resulting in a
         smaller encoded size. The disadvantage is that the resulting JSON
         text is encoded in latin1 (and must correctly be treated as such
-        when storing and transfering), a rare encoding for JSON. It is
+        when storing and transferring), a rare encoding for JSON. It is
         therefore most useful when you want to store data structures known
         to contain binary data efficiently in files or databases, not when
         talking to other JSON encoders/decoders.
           JSON::XS->new->latin1->encode (["\x{89}\x{abc}"]
         bytewise/binary I/O. In future versions, enabling this option might
         enable autodetection of the UTF-16 and UTF-32 encoding families, as
         described in RFC4627.
         If $enable is false, then the "encode" method will return the JSON
-        string as a (non-encoded) unicode string, while "decode" expects
+        string as a (non-encoded) Unicode string, while "decode" expects
-        thus a unicode string. Any decoding or encoding (e.g. to UTF-8 or
+        thus a Unicode string. Any decoding or encoding (e.g. to UTF-8 or
         UTF-16) needs to be done yourself, e.g. using the Encode module.
         Example, output UTF-16BE-encoded JSON:
           use Encode;
            }
     $json = $json->indent ([$enable])
         If $enable is true (or missing), then the "encode" method will use a
         multiline format as output, putting every array member or
-        object/hash key-value pair into its own line, identing them
+        object/hash key-value pair into its own line, indenting them
         properly.
         If $enable is false, no newlines or indenting will be produced, and
-        the resulting JSON text is guarenteed not to contain any "newlines".
+        the resulting JSON text is guaranteed not to contain any "newlines".
         This setting has no effect when decoding JSON texts.
     $json = $json->space_before ([$enable])
         If $enable is true (or missing), then the "encode" method will add
         Example, space_before and indent disabled, space_after enabled:
            {"key": "value"}
+    $json = $json->relaxed ([$enable])
+        If $enable is true (or missing), then "decode" will accept some
+        extensions to normal JSON syntax (see below). "encode" will not be
+        affected in anyway. *Be aware that this option makes you accept
+        invalid JSON texts as if they were valid!*. I suggest only to use
+        this option to parse application-specific files written by humans
+        (configuration files, resource files etc.)
+        If $enable is false (the default), then "decode" will only accept
+        valid JSON texts.
+        Currently accepted extensions are:
+        * list items can have an end-comma
+            JSON *separates* array elements and key-value pairs with commas.
+            This can be annoying if you write JSON texts manually and want
+            to be able to quickly append elements, so this extension accepts
+            comma at the end of such items not just between them:
+               [
+                  1,
+                  2, <- this comma not normally allowed
+               ]
+               {
+                  "k1": "v1",
+                  "k2": "v2", <- this comma not normally allowed
+               }
+        * shell-style '#'-comments
+            Whenever JSON allows whitespace, shell-style comments are
+            additionally allowed. They are terminated by the first
+            carriage-return or line-feed character, after which more
+            white-space and comments are allowed.
+              [
+                 1, # this comment not allowed in JSON
+                    # neither this one...
+              ]
     $json = $json->canonical ([$enable])
         If $enable is true (or missing), then the "encode" method will
         output JSON objects by sorting their keys. This is adding a
         comparatively high overhead.
         pairs in the order Perl stores them (which will likely change
         between runs of the same script).
         This option is useful if you want the same data structure to be
         encoded as the same JSON text (given the same overall settings). If
-        it is disabled, the same hash migh be encoded differently even if
+        it is disabled, the same hash might be encoded differently even if
         contains the same data, as key-value pairs have no inherent ordering
         in Perl.
         This setting has no effect when decoding JSON texts.
            => "Hello, World!"
     $json = $json->allow_blessed ([$enable])
         If $enable is true (or missing), then the "encode" method will not
         barf when it encounters a blessed reference. Instead, the value of
-        the convert_blessed option will decide wether "null"
+        the convert_blessed option will decide whether "null"
         ("convert_blessed" disabled or no "to_json" method found) or a
         representation of the object ("convert_blessed" enabled and
         "to_json" method found) is being encoded. Has no effect on "decode".
         If $enable is false (the default), then "encode" will throw an
         As this callback gets called less often then the
         "filter_json_object" one, decoding speed will not usually suffer as
         much. Therefore, single-key objects make excellent targets to
         serialise Perl objects into, especially as single-key JSON objects
-        are as close to the type-tagged value concept as JSON gets (its
+        are as close to the type-tagged value concept as JSON gets (it's
         basically an ID/VALUE tuple). Of course, JSON does not support this
         in any way, so you need to make sure your data never looks like a
         serialised Perl hash.
         Typical names for the single object key are "__class_whatever__", or
     vice versa. These mappings are designed to "do the right thing" in most
     circumstances automatically, preserving round-tripping characteristics
     (what you put in comes out as something equivalent).
     For the more enlightened: note that in the following descriptions,
-    lowercase *perl* refers to the Perl interpreter, while uppcercase *Perl*
+    lowercase *perl* refers to the Perl interpreter, while uppercase *Perl*
     refers to the abstract Perl language itself.
   JSON -> PERL
     object
         A JSON object becomes a reference to a hash in Perl. No ordering of
-        object keys is preserved (JSON does not preserver object key
+        object keys is preserved (JSON does not preserve object key ordering
-        ordering itself).
+        itself).
     array
         A JSON array becomes a reference to an array in Perl.
     string
         strings, but as Perl is typeless there is no other way to do it.
     true, false
         These JSON atoms become "JSON::XS::true" and "JSON::XS::false",
         respectively. They are overloaded to act almost exactly like the
-        numbers 1 and 0. You can check wether a scalar is a JSON boolean by
+        numbers 1 and 0. You can check whether a scalar is a JSON boolean by
         using the "JSON::XS::is_bool" function.
     null
         A JSON null atom becomes "undef" in Perl.
            to_json [\0,JSON::XS::true]      # yields [false,true]
     JSON::XS::true, JSON::XS::false
         These special values become JSON true and JSON false values,
-        respectively. You cna alos use "\1" and "\0" directly if you want.
+        respectively. You can also use "\1" and "\0" directly if you want.
     blessed objects
         Blessed objects are not allowed. JSON::XS currently tries to encode
         their underlying representation (hash- or arrayref), but this
         behaviour might change in future versions.
            to_json [$value]                 # yields ["5"]
            # undef becomes null
            to_json [undef]                  # yields [null]
-        You can force the type to be a string by stringifying it:
+        You can force the type to be a JSON string by stringifying it:
            my $x = 3.1; # some variable containing a number
            "$x";        # stringified
            $x .= "";    # another, more awkward way to stringify
            print $x;    # perl does it for you, too, quite often
-        You can force the type to be a number by numifying it:
+        You can force the type to be a JSON number by numifying it:
            my $x = "3"; # some variable containing a string
            $x += 0;     # numify it, ensuring it will be dumped as a number
-           $x *= 1;     # same thing, the choise is yours.
+           $x *= 1;     # same thing, the choice is yours.
-        You can not currently output JSON booleans or force the type in
+        You can not currently force the type in other, less obscure, ways.
-        other, less obscure, ways. Tell me if you need this capability.
+        Tell me if you need this capability.
 COMPARISON
     As already mentioned, this module was created because none of the
     existing JSON modules could be made to work correctly. First I will
     describe the problems (or pleasures) I encountered with various existing
     not to suffer from any of these problems or limitations.
     JSON 1.07
         Slow (but very portable, as it is written in pure Perl).
-        Undocumented/buggy Unicode handling (how JSON handles unicode values
+        Undocumented/buggy Unicode handling (how JSON handles Unicode values
-        is undocumented. One can get far by feeding it unicode strings and
+        is undocumented. One can get far by feeding it Unicode strings and
-        doing en-/decoding oneself, but unicode escapes are not working
+        doing en-/decoding oneself, but Unicode escapes are not working
         properly).
-        No roundtripping (strings get clobbered if they look like numbers,
+        No round-tripping (strings get clobbered if they look like numbers,
         e.g. the string 2.0 will encode to 2.0 instead of "2.0", and that
         will decode into the number 2.
     JSON::PC 0.01
         Very fast.
         Undocumented/buggy Unicode handling.
-        No roundtripping.
+        No round-tripping.
         Has problems handling many Perl values (e.g. regex results and other
         magic values will make it croak).
         Does not even generate valid JSON ("{1,2}" gets converted to "{1:2}"
         much undocumented. I need at least a format for easy reading by
         humans and a single-line compact format for use in a protocol, and
         preferably a way to generate ASCII-only JSON texts).
         Completely broken (and confusingly documented) Unicode handling
-        (unicode escapes are not working properly, you need to set
+        (Unicode escapes are not working properly, you need to set
         ImplicitUnicode to *different* values on en- and decoding to get
         symmetric behaviour).
-        No roundtripping (simple cases work, but this depends on wether the
+        No round-tripping (simple cases work, but this depends on whether
-        scalar value was used in a numeric context or not).
+        the scalar value was used in a numeric context or not).
         Dumping hashes may skip hash values depending on iterator state.
         Unmaintained (maintainer unresponsive for many months, bugs are not
         getting fixed).
         Does not check input for validity (i.e. will accept non-JSON input
         and return "something" instead of raising an exception. This is a
-        security issue: imagine two banks transfering money between each
+        security issue: imagine two banks transferring money between each
         other using JSON. One bank might parse a given non-JSON request and
         deduct money, while the other might reject the transaction with a
         syntax error. While a good protocol will at least recover, that is
         extra unnecessary work and the transaction will still not succeed).
     JSON::DWIW 0.04
         Very fast. Very natural. Very nice.
-        Undocumented unicode handling (but the best of the pack. Unicode
+        Undocumented Unicode handling (but the best of the pack. Unicode
         escapes still don't get parsed properly).
         Very inflexible.
-        No roundtripping.
+        No round-tripping.
         Does not generate valid JSON texts (key strings are often unquoted,
         empty keys result in nothing being output)
         Does not check input for validity.
        my $yaml = $to_yaml->encode ($ref) . "\n";
     This will usually generate JSON texts that also parse as valid YAML.
     Please note that YAML has hardcoded limits on (simple) object key
     lengths that JSON doesn't have, so you should make sure that your hash
-    keys are noticably shorter than the 1024 characters YAML allows.
+    keys are noticeably shorter than the 1024 characters YAML allows.
     There might be other incompatibilities that I am not aware of. In
     general you should not try to generate YAML with a JSON generator or
     vice versa, or try to parse JSON with a YAML parser or vice versa:
     chances are high that you will run into severe interoperability
        JSON::XS/3 | 338250.323 | 218453.333 |
        Storable   |  16500.016 | 135300.129 |
        -----------+------------+------------+
     That is, JSON::XS is about five times faster than JSON::DWIW on
-    encoding, about three times faster on decoding, and over fourty times
+    encoding, about three times faster on decoding, and over forty times
     faster than JSON, even with pretty-printing and key sorting. It also
     compares favourably to Storable for small amounts of data.
     Using a longer test string (roughly 18KB, generated from Yahoo! Locals
     search API (http://nanoref.com/yahooapis/mgPdGg):
        -----------+------------+------------+
     Again, JSON::XS leads by far (except for Storable which non-surprisingly
     decodes faster).
-    On large strings containing lots of high unicode characters, some
+    On large strings containing lots of high Unicode characters, some
     modules (such as JSON::PC) seem to decode faster than JSON::XS, but the
-    result will be broken due to missing (or wrong) unicode handling. Others
+    result will be broken due to missing (or wrong) Unicode handling. Others
     refuse to decode or encode properly, so it was impossible to prepare a
     fair comparison table for that case.
 SECURITY CONSIDERATIONS
     When you are using JSON in a protocol, talking to untrusted potentially
     have any buffer overflows. Obviously, this module should ensure that and
     I am trying hard on making that true, but you never know.
     Second, you need to avoid resource-starving attacks. That means you
     should limit the size of JSON texts you accept, or make sure then when
-    your resources run out, thats just fine (e.g. by using a separate
+    your resources run out, that's just fine (e.g. by using a separate
     process that can crash safely). The size of a JSON text in octets or
     characters is usually a good indication of the size of the resources
     required to decode it into a Perl structure. While JSON::XS can check
     the size of the JSON text, it might be too late when you already have it
     in memory, so you might want to check the size before you accept the
     And last but least, something else could bomb you that I forgot to think
     of. In that case, you get to keep the pieces. I am always open for
     hints, though...
-    If you are using JSON::XS to return packets to consumption by javascript
+    If you are using JSON::XS to return packets to consumption by JavaScript
     scripts in a browser you should have a look at
-    <http://jpsykes.com/47/practical-csrf-and-json-security> to see wether
+    <http://jpsykes.com/47/practical-csrf-and-json-security> to see whether
     you are vulnerable to some common attack vectors (which really are
     browser design bugs, but it is still you who will have to deal with it,
     as major browser developers care only for features, not about doing
     security right).
+THREADS
+    This module is *not* guaranteed to be thread safe and there are no plans
+    to change this until Perl gets thread support (as opposed to the
+    horribly slow so-called "threads" which are simply slow and bloated
+    process simulations - use fork, its *much* faster, cheaper, better).
+    (It might actually work, but you have been warned).
 BUGS
     While the goal of this module is to be correct, that unfortunately does
     not mean its bug-free, only that I think its design is bug-free. It is
     still relatively early in its development. If you keep reporting bugs
     they will be fixed swiftly, though.
+    Please refrain from using rt.cpan.org or any other bug reporting
+    service. I put the contact address into my modules for a reason.
 AUTHOR
      Marc Lehmann <schmorp@schmorp.de>
      http://home.schmorp.de/

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Comparing JSON-XS/README (file contents): Revision 1.16 by root, Thu Jul 26 11:33:35 2007 UTC vs. Revision 1.20 by root, Tue Nov 13 22:59:08 2007 UTC

Diff Legend

Comparing JSON-XS/README (file contents):
Revision 1.16 by root, Thu Jul 26 11:33:35 2007 UTC vs.
Revision 1.20 by root, Tue Nov 13 22:59:08 2007 UTC