(!****************************************************** Mosel Example Programs ====================== file json.mos ````````````` Package providing advanced union operators for representing a JSON document (c) 2022 Fair Isaac Corporation author: Y. Colombani, Nov. 2021 *******************************************************!) package json version 0.1.0 uses 'mmxml','mmsystem','mmhttp' ! **** Package type definitions **** public declarations !@doc.descr Type definition: JSON object jobj=array(string) of any !@doc.descr Type definition: JSON array jarr=array(range) of any !@doc.descr Type definition: a null value is stored as a string jnull=string !@doc.descr Type definition: JSON value !@doc.info A 'jval' is either a scalar of type real, text, boolean, or jobj, jarr or jnull. jval=text or real or boolean or jobj or jarr or jnull end-declarations ! **** [private] Parser related data **** !@doc.ignore declarations afct:array(range) of any ! jparser callbacks public jsctx= record l:list of jval ! List of active elements end-record datafile="forjson"+newmuid ! Unique identifier for temp. filename jstxt=newmuid ! Unique identifier for temp. output filename end-declarations ! **** Public subroutines **** (!@doc. @descr Retrieve the indexing set of a 'jobj' entity @param o JSON object @return indexing set (set of labels occurring in the JSON object) !) public function getfields(o:jobj):set of string returned:=o.index(1) end-function (!@doc. @descr Retrieve the indexing (range) set of a 'jarr' entity @param o JSON array @return index range set (position count of objects within the JSON array) @info Index numbering starts with the value 1. !) public function getrange(o:jarr):range returned:=o.index(1) end-function (!@doc. @descr Load a JSON document @param fname (extended) file name of a JSON document @param doc structure for storing the JSON contents @return 0 if successful, 1 in case of parsing error. @info The entity 'doc' passed as argument is reset by this function. !) public function loadjson(fname:text,doc:jval):integer declarations ctx:jsctx end-declarations reset(doc) fopen(fname,F_INPUT) returned:=jsonparse(afct,ctx) ! Invoke the JSON parsing fclose(F_INPUT) if ctx.l.size>0 then doc:=ctx.l(1) end-if end-function (!@doc. @descr Parse a text as a JSON document @param data text containing JSON data @param doc structure for storing the JSON contents @return 0 if successful, 1 in case of parsing error. @info The entity 'doc' passed as argument is reset by this function. @related Invokes <fctRef>loadjson</fctRef> !) public function parsejson(data:text,doc:jval):integer publish(datafile,data) returned:=loadjson(text("text:")+datafile,doc) unpublish(datafile) end-function (!@doc. @descr Create a JSON representation in text form for a Mosel entity @param mosobj a Mosel entity @param flag optional format configuration (see documentation of 'jsonwrite') !) public function jsontext(mosobj:any):text publish(jstxt,returned) jsonwrite("text:"+jstxt,mosobj) unpublish(jstxt) end-function public function jsontext(mosobj:any, flag:integer):text publish(jstxt,returned) jsonwrite("text:"+jstxt,mosobj,flag) unpublish(jstxt) end-function !---------------------------Internal subroutines---------------------------- ! jparser callback: open an object function js_open_object(ctx:jsctx, name:text):integer if ctx.l.size>0 then with o=ctx.l(ctx.l.size) do if o is jobj then sname:=string(name) create(o.jobj(sname).jobj) ctx.l+=[o.jobj(sname).jobj] else ! jarr create(o.jarr(o.jarr.size+1).jobj) ctx.l+=[o.jarr(o.jarr.size).jobj] end-if end-do else ctx.l+=[(jobj)] end-if end-function ! jparser callback: close an object function js_close_object(ctx:jsctx):integer if ctx.l.size>1 then cuttail(ctx.l,1) end-if end-function ! jparser callback: open an array function js_open_array(ctx:jsctx, name:text):integer if ctx.l.size>0 then with o=ctx.l(ctx.l.size) do if o is jobj then sname:=string(name) create(o.jobj(sname).jarr) ctx.l+=[o.jobj(sname).jarr] else ! jarr create(o.jarr(o.jarr.size+1).jarr) ctx.l+=[o.jarr(o.jarr.size).jarr] end-if end-do else ctx.l+=[(jarr)] end-if end-function ! jparser callback: close an array function js_close_array(ctx:jsctx):integer if ctx.l.size>1 then cuttail(ctx.l,1) end-if end-function ! jparser callback: a textual value function js_text_val(ctx:jsctx, name:text, type:integer, val:text):integer if ctx.l.size>0 then with o=ctx.l(ctx.l.size) do if o is jobj then o.jobj(string(name)):=val else ! jarr o.jarr(o.jarr.size+1):=val end-if end-do else ctx.l+=[val] end-if end-function ! jparser callback: a numerical value function js_num_val(ctx:jsctx, name:text, val:real):integer if ctx.l.size>0 then with o=ctx.l(ctx.l.size) do if o is jobj then o.jobj(string(name)):=val else ! jarr o.jarr(o.jarr.size+1):=val end-if end-do else ctx.l+=[val] end-if end-function ! jparser callback: a Boolean value function js_bool_val(ctx:jsctx, name:text, val:boolean):integer if ctx.l.size>0 then with o=ctx.l(ctx.l.size) do if o is jobj then o.jobj(string(name)):=val else ! jarr o.jarr(o.jarr.size+1):=val end-if end-do else ctx.l+=[val] end-if end-function ! jparser callback: the 'null' value function js_null_val(ctx:jsctx, name:text):integer if ctx.l.size>0 then with o=ctx.l(ctx.l.size) do if o is jobj then o.jobj(string(name)):="null" else ! jarr o.jarr(o.jarr.size+1):="null" end-if end-do else ctx.l+=["null"] end-if end-function ! Module initialisation (definition of JSON parser callbacks) afct(JSON_FCT_OPEN_OBJ):=->js_open_object afct(JSON_FCT_CLOSE_OBJ):=->js_close_object afct(JSON_FCT_OPEN_ARR):=->js_open_array afct(JSON_FCT_CLOSE_ARR):=->js_close_array afct(JSON_FCT_TEXT):=->js_text_val afct(JSON_FCT_NUM):=->js_num_val afct(JSON_FCT_BOOL):=->js_bool_val afct(JSON_FCT_NULL):=->js_null_val end-package