[x3d-public] renewed development of X3D JSON support

[John Carlson]

I've put the converted schema through the Ajv 8 validator. Here's what 
I've gotten so far, with HelloWorld.json.  I don't know if the problem 
stems from Ajv or the schema, or the HelloWorld.json.  One reason why I 
had to take out pattern match was the XML Schema regular expressions 
were not the same as the JavaScript regular expressions.  I'm not sure 
how portable regular expressions are between encodings, in other words.  
Any I don't really know what XMLSpy has done.  Maybe check documentation 
about regexps on Altova's website.

John


~/x3dschema$ node validatex3djson.js 
/c/x3d-code/www.web3d.org/x3d/content/examples/HelloWorld.json
Failed JSON parse 
/c/x3d-code/www.web3d.org/x3d/content/examples/HelloWorld.json 
SyntaxError: Invalid regular expression: 
/^([\d\--\.\:A-Z_a-z·À-ÖØ-öø-ͽͿ-ٟ٪-ۯۺ-޿ߊ-॥॰-৥ৰ-੥ੰ-૥૰-୥୰-௥௰-౥౰-೥೰-൥൰-෥෰-๏๚-໏໚-༟༪-ဿ၊-ႏႚ-៟៪-᠏᠚-᥅ᥐ-᧏᧚-᩿᪊-᪏᪚-᭏᭚-ᮯᮺ-᰿᱊-ᱏᱚ-῿-‿-⁀⁰-↏Ⰰ-⿯、-ꘟꘪ-꣏꣚-ꤊ-ꧏ꧚-ꧯꧺ-꩏꩚-꯯꯺-퟿豈-﷏ﷰ-／：-�𐀀-𐒟𐒪-𑁥𑁰-𑃯𑃺-𑄵𑅀-𑇏𑇚-𑋯𑋺-𑑏𑑚-𑓏𑓚-𑙏𑙚-𑚿𑛊-𑜯𑜺-𑣟𑣪-𑱏𑱚-𖩟𖩪-𖭏𖭚-𝟍𝠀-𞥏𞥚-󯿿]+)$/: 
Invalid escape
     at new RegExp (<anonymous>)
     at usePattern 
(/home/coderextreme/x3dschema/node_modules/ajv/dist/vocabularies/code.js:72:14)
     at Object.code 
(/home/coderextreme/x3dschema/node_modules/ajv/dist/vocabularies/validation/pattern.js:19:109)
     at keywordCode 
(/home/coderextreme/x3dschema/node_modules/ajv/dist/compile/validate/index.js:454:13)
     at 
/home/coderextreme/x3dschema/node_modules/ajv/dist/compile/validate/index.js:222:17
     at CodeGen.code 
(/home/coderextreme/x3dschema/node_modules/ajv/dist/compile/codegen/index.js:439:13)
     at CodeGen.block 
(/home/coderextreme/x3dschema/node_modules/ajv/dist/compile/codegen/index.js:568:18)
     at iterateKeywords 
(/home/coderextreme/x3dschema/node_modules/ajv/dist/compile/validate/index.js:219:9)
     at groupKeywords 
(/home/coderextreme/x3dschema/node_modules/ajv/dist/compile/validate/index.js:200:13)
     at 
/home/coderextreme/x3dschema/node_modules/ajv/dist/compile/validate/index.js:192:13