[x3d-public] uRE: summary of remaining JSON parse errors

[Roy Walmsley]

Hi,

 

In JSON you do not escape a single quote (apostrophe). However, you do escape a reverse solidus and you do escape a double quote.

 

So, if you have the XML string 

 

                                        'string [ \"proxy is\" \"any-order child\" \"of Collision\" ]' +

 

it needs to be understood as an XML string. Consider the corresponding UNICODE code points. One interesting illustrative sequence is as follows:

 

…

g              U+0067

space    U+0020

[              U+005b

space    U+0020

\              U+005c

“              U+0022

p             U+0070

…

 

Notice that the reverse solidus and the double quote are treated as separate characters. There is no escape sequence \” in  XML.

 

So, how are these code points represented in a text string in JSON? There we do have escape sequences. U+005c is \\ and U+0022 is \”. So, the full text string becomes:

 

                                        'string [ \\\"proxy is\\\" \\\"any-order child\\\" \\\"of Collision\\\" ]' +

 

Roy

 

From: John Carlson [mailto:yottzumm at gmail.com] 
Sent: 01 March 2016 17:45
To: Don Brutzman
Cc: Roy Walmsley; X3D Graphics public mailing list
Subject: Re: summary of remaining JSON parse errors

 

Results. 

 

examples//Basic/development/ProxyShapeExample.json

 

 It looks like you’re \ escaping a \ in front of a “ (double quote) which is probably bad.  This preamble in a string is bad because you’re not quoting the “:  "\t\t 'string [ \\ <file:///\\%22proxy> "proxy is\\”

 

The double quote after the tab is bad.  You should escape a \ in front of a single quote I think, to make it \\' <smb://'> , since \’ is bad. And you should escape standalone double quotes.   \” should be left alone?  I am not sure.  Sorry for any confusion.

 

examples//Basic/development/SchemaTest.json
[Error: Parse error on line 71:
... at translation <mailto:... at translation%22:[10000.e-1,50,0.5> ":[10000.e-1,50,0.5],      
-----------------------^

Expecting 'EOF', '}', ',', ']', got 'undefined’]

 

Remove decimal point.

 

These files still have issues with metadata:

 

examples//Savage/Robots/UnmannedAirVehicles/ScanEagle.json

[Error: Parse error on line 173:

...                    { "MetadataString":

-----------------------^

Expecting 'STRING', got '{']

examples//Savage/Robots/UnmannedAirVehicles/SeaScan.json

[Error: Parse error on line 144:

...                    { "MetadataString":

-----------------------^

Expecting 'STRING', got '{']

examples//Savage/Robots/UnmannedSurfaceVehicles/SeaFox.json

[Error: Parse error on line 173:

...                    { "MetadataString":

-----------------------^

Expecting 'STRING', got '{']

examples//Savage/Robots/UnmannedSurfaceVehicles/SeaFoxOriginal.json

[Error: Parse error on line 151:

...                    { "MetadataString":

-----------------------^

Expecting 'STRING', got '{']

examples//Savage/ShipsMilitary/FFG-7OliverHazardPerry-UnitedStates/OliverHazardPerryFFG.json

[Error: Parse error on line 215:

...                    { "MetadataString":

-----------------------^

Expecting 'STRING', got '{']

 

On Mar 1, 2016, at 10:06 AM, Don Brutzman <brutzman at nps.edu> wrote:

 

Last night's build went OK.

Found and amended code block (template output-reals) to insert missing 0 after decimal point, before scientific notation (e.g. 1.e2 converted to 1.0e2).

Marked ScriptSyntaxExample.x3d meta information as a test scene.

Many of your error cases in log file were test scenes or archived backups, not working scenes.  I'll keep scrutinizing and pursuing problems in the list.




On 2/26/2016 2:18 PM, John Carlson wrote:



Some number formatting issues (need digit after .)
Escaping issues
ContainerField naming or object attribute value braces missing.
‘,’ value is missing.
Bad source documents (not X3D).
-metadata should be an array or a containerField.


all the best, Don
-- 
Don Brutzman  Naval Postgraduate School, Code USW/Br       brutzman at nps.edu
Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA   +1.831.656.2149
X3D graphics, virtual worlds, navy robotics http://faculty.nps.edu/brutzman

 

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