Array Confusion [was: Re: Does 'exists' work on arrays?]

Mike Bonner bonnmike at gmail.com
Sun Mar 15 15:38:06 EDT 2015 

try " put the keys of gGeneralArray["gpx"] and you'll get the next level of
keys.

On Sun, Mar 15, 2015 at 1:27 PM, Graham Samuel <livfoss at mac.com> wrote:

> Thanks Peter, it seems to work very well. I tried it on my XML-derived
> test file, which I put (as an array) into a global, gGeneralArray.
>
> Hoping you’ll excuse the bandwidth, I’ll show you the first few lines of
> text from your function's output, as I would like to ask a question about
> it:
>
>  gpx
>    @attributes
>       creator: Geolives
>       schemaLocation: http://www.topografix.com/GPX/1/1
> http://www.topografix.com/GPX/1/1/gpx.xsd
>       version: 1.1
>       xmlns: http://www.topografix.com/GPX/1/1
>    metadata:
>    trk
>       trkseg
>          trkpt[1000]
>             @attributes
>                lat: 43.099438
>                lon: 2.075522
>             ele: 392.6022
>             time: 2015-03-12T10:34:43Z
>          trkpt[1001]
>             @attributes
>                lat: 43.099384
>                lon: 2.0755
>             ele: 392.6022
>             time: 2015-03-12T10:34:47Z
>          trkpt[1002]
>             @attributes
>                lat: 43.099335
>                lon: 2.075483
>             ele: 393.96625
>             time: 2015-03-12T10:34:51Z
>
> This seems to me to show a multidimensional array, but perhaps it doesn’t,
> because when I do this in the Message Box
>
>  put the keys of gGeneralArray
>
> I just get
>
>   gpx
>
> But I can see all the other keys (can’t I?) in above display and in the
> IDE - they derive from different levels of angle brackets in the XML.
> Perhaps I’m simply going crazy.
>
> Just going back to my model of LC arrays - can someone tell me if this is
> reasonable:
>
> An array is a kind of group, or a physical analogy would be a box. This
> group (box) contains elements which can be actual objects (numbers for
> example) or other groups (boxes). This nesting can go on as deep as you
> like. So a reference like
>
>  myArray[“aa”][“bb”]
>
> means ‘get me out the box or object labelled “bb” from the box labelled
> “aa”. We only find out if it’s a box (i.e. another array) or a real object
> when we go to fetch it.
>
> I’m using this model to get as far away as possible from the numerically
> indexed arrays I was brought up with. Is it wrong?
>
> TIA
>
> Graham
> > On 15 Mar 2015, at 19:32, Peter M. Brigham <pmbrig at gmail.com> wrote:
> >
> > Not a utility, but here's a way of displaying a multilevel array so you
> can see its structure.
> >
> > -- Peter
> >
> > Peter M. Brigham
> > pmbrig at gmail.com
> > http://home.comcast.net/~pmbrig
> >
> > -------
> >
> > function displayArray @pArray, pFullData, _pDimension
> >   -- by Peter M. Brigham, pmbrig at gmail.com — freeware
> >   -- adapted from a handler by Trevor DeVore
> >   -- displays an array as an outline-style list
> >   -- most useful for multidimensional arrays, to see the structure
> >   -- if an element of the array contains more than one line,
> >   --    the first line only will be displayed (less confusing to look at)
> >   -- if you want to see the full data then pass pFullData = true
> >   -- _pDimension is an internally used parameter
> >   -- pArray is referenced to avoid duplicating large arrays in memory,
> >   --    but the array is not altered by this function
> >
> >   -- call it like this: put displayArray(tArray) into fld "peruse"
> >
> >   -- requires makestring()
> >
> >   if _pDimension is empty then put 0 into _pDimension
> >   if pFullData = empty then put false into pFullData
> >   put ": " into divString
> >   put the keys of pArray into theKeys
> >   if line 1 of theKeys is a number then
> >      sort theKeys numeric
> >   else
> >      sort theKeys
> >   end if
> >   repeat for each line theKey in theKeys
> >      if pArray[theKey] is an array then
> >         put makeString(space,_pDimension*3) & theKey & cr after theText
> >         put pArray[theKey] into theTempArray
> >         put displayArray(theTempArray, pFullData, _pDimension + 1) after
> theText
> >      else
> >         if pFullData then
> >            put makeString(space,_pDimension*3) & theKey & ":" \
> >                  && pArray[theKey] & cr after theText
> >         else
> >            put pArray[theKey] into tElement
> >            put empty into tTrailer
> >            if the number of lines of tElement > 1 then
> >               put " ..." into tTrailer
> >            end if
> >            put makeString(space,_pDimension*3) & theKey & divString \
> >                  & (line 1 of tElement) & tTrailer & cr after theText
> >         end if
> >      end if
> >   end repeat
> >   return theText
> > end displayArray
> >
> > function makeString pChar, n
> >   -- returns a string of n characters (pChar)
> >   -- no repeat loop!
> >   -- by Peter M. Brigham, pmbrig at gmail.com — freeware
> >   -- improved by Richard Gaskin
> >   set the linedel to pChar
> >   put pChar into line n of temp
> >   return temp
> > end makeString
> >
> >
> > On Mar 15, 2015, at 2:19 PM, Mike Bonner wrote:
> >
> >> If you are just trying to get a handle on the structure, and how to pull
> >> out specific chunks, you can declare it global, and use the message box
> to
> >> poke around.
> >>
> >> If its global, in the multiline msg box declare it too, and "put the
> keys
> >> of... "
> >> Then adjust it to look at subkey contents, poking around till you figure
> >> out where things are.
> >>
> >> And now i'm wondering if anyone has built an array browser utility?
> >>
> >> On Sun, Mar 15, 2015 at 11:56 AM, Scott Rossi <scott at tactilemedia.com>
> >> wrote:
> >>
> >>> Try:  if myArray is an array
> >>>
> >>>
> >>> Regards,
> >>>
> >>> Scott Rossi
> >>> Creative Director
> >>> Tactile Media, UX/UI Design
> >>>
> >>>
> >>>
> >>>
> >>> On 3/15/15, 9:50 AM, "Graham Samuel" <livfoss at mac.com> wrote:
> >>>
> >>>> Still struggling with arrays: no results, no error messages,  no dataŠ
> >>>> will get there no doubt. While trying to get there, I tried
> >>>>
> >>>> put exists(myArray[³gpx²])
> >>>>
> >>>> I got Œfalse¹, but the IDE seems to say that the top key in this
> >>>> multidimensional array is ³gpx², so why isn¹t it true?
> >>>>
> >>>> Puzzled on a wet Sunday afternoonŠ
> >>>>
> >>>> Graham
> >>>>
> >>>>
> >>>>
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