[]              (sublist contains array)
{}              (sublist contains object)    
string          (string scalar)
scalar          (number, true, false, null)
"name":"string" (name:value pair)
"name":scalar   (name:value pair)
"name":{}       (value part of pair is object in sublist)
"name":[]       (value part of pair is array in sublist)

{ "store": {
    "book": [ 
      { "category": "reference",
        "author": "Nigel Rees",
        "title": "Sayings of the Century",
        "price": 8.95
      },
      { "category": "fiction",
        "author": "Evelyn Waugh",
        "title": "Sword of Honour",
        "price": 12.99
      },
      { "category": "fiction",
        "author": "Herman Melville",
        "title": "Moby Dick",
        "isbn": "0-553-21311-3",
        "price": 8.99
      },
      { "category": "fiction",
        "author": "J. R. R. Tolkien",
        "title": "The Lord of the Rings",
        "isbn": "0-395-19395-8",
        "price": 22.99
      }
    ],
    "bicycle": {
      "color": "red",
      "price": 19.95
    }
  }
}

> {}
  > "store":{}
    > "book":[]
      > {}
        > "category":"reference"
        > "author":"Nigel Rees"
        > "title":"Sayings of the Century"
        > "price":8.95
      > {}
        > "category":"fiction"
        > "author":"Evelyn Waugh"
        > "title":"Sword of Honour"
        > "price":12.99
      > {}
        > "category":"fiction"
        > "author":"Herman Melville"
        > "title":"Moby Dick"
        > "isbn":"0-553-21311-3"
        > "price":8.99
      > {}
        > "category":"fiction"
        > "author":"Evelyn Waugh"
        > "title":"Sword of Honour"
        > "price":12.99
      > {}
        > "category":"fiction"
        > "author":"Herman Melville"
        > "title":"Moby Dick"
        > "isbn":"0-553-21311-3"
        > "price":8.99
      > {}
        > "category":"fiction"
        > "author":"J. R. R. Tolkien"
        > "title":"The Lord of the Rings"
        > "isbn":"0-395-19395-8"
        > "price":22.99
    > "bicycle":{}
      > "color":"red"
      > "price":19.95

!---------------------------------------------------------------------
!Function:
!   parse a JSON array or object, up to final "]" or "}"
!Params:
!   $json()  (mlist) [ref] - parsed JSON data stored here (see notes at top)
!   endtoken$ (s) [in] - ending token to look for ("]" or "}")
!Returns:
!   >= 0 for success
!   < 0 for error
!Module vars:
!   chin, workbuf$
!Notes:
!---------------------------------------------------------------------
Function Fn'MLJ'Parse($json() as mlist(varstr), endtoken$ as s2:inputonly) as i4
    map1 locals
        map2 token$,s,0
        map2 status,i,4
        map2 bdone,BOOLEAN
        map2 subendtoken$,s,2
    
    level += 1
    do 
        ! get next [,{,],},name:{,name:[, or scalar from file
        token$ = fn'mlj'next'token$()
            
        switch token$
            case "["            ! parse a new array
            case "{"            ! parse an object
                $json(.pushback) = token$
                subendtoken$ = ifelse$(token$="[","]","}")
                status = Fn'MLJ'Parse($json(.back).sublist,subendtoken$)
                if status >= 0 then
                    $json(.back) += subendtoken$
                else 
                    $json(.back) += " !!Error: missing terminator: "+subendtoken$
                endif
                exit
            case "]"
            case "}"
                status = ifelse(token$=endtoken$,0,-1)
                bdone = .TRUE
                exit
            case ""             ! no more data (error?)
                bdone = .TRUE
                status = -1
                exit
            default
                switch token$[-1,-1]
                    case "{"            ! name:{
                    case "["            ! name:[
                        $json(.pushback) = token$
                        subendtoken$ = ifelse$(token$[-1,-1]="[","]","}")
                        status = Fn'MLJ'Parse($json(.back).sublist,subendtoken$)
                        if status >= 0 then
                            $json(.back) += subendtoken$
                        else 
                            $json(.back) += " !!Error: missing terminator: "+subendtoken$
                        endif
                        exit
                    default
                        ! add an name:value, or scalar element to our list
                        $json(.pushback) = token$
                        exit
                endswitch
                exit
        endswitch
    loop until bdone
    
    if status < 0 then
        Fn'MLJ'Parse = -1
    endif
    level -= 1
EndFunction

xcall JSON,1,handle,status,jsonstring$,$jsonmap()

/store/bicycle/color = red
/store/bicycle/price = red
/store/book[1]/author = Nigel Rees
/store/book[1]/category = reference
/store/book[1]/price = 8.95
/store/book[1]/title = Sayings of the Century
/store/book[2]/author = Evelyn Waugh
/store/book[2]/category = fiction
/store/book[2]/price = 12.99
/store/book[2]/title = Sword of Honour
/store/book[3]/author = Herman Melville
/store/book[3]/category = fiction
/store/book[3]/isbn = 0-553-21311-3
/store/book[3]/price = 8.99
/store/book[3]/title = Moby Dick
/store/book[4]/author = J. R. R. Tolkien
/store/book[4]/category = fiction
/store/book[4]/isbn = 0-395-19395-8
/store/book[4]/price = 22.99
/store/book[4]/title = The Lord of the Rings

! test limits of input line into s,0

map1 n,f
map1 pline,s,0
map1 i,f

    input "Enter # bytes to test: ",n

    ! Create file with one long line...
    open #1, "inputs0.lst", output
    for i = 1 to n
        ? #1, "a";
    next i
    close #1

    ! now try to read it
    open #1, "inputs0.lst", input
    input line #1, pline
    close #1

    ? "len(pline) = ";len(pline)
    ? pline[1,70];"..."
end