Sorting Arrays

[Alex Tweedly]

On 11/08/2023 23:00, J. Landman Gay via use-livecode wrote:
> On 8/10/23 2:29 PM, Alex Tweedly via use-livecode wrote:
> [ ... code from earlier posting ...]

> I couldn't get this to work until I altered it, but I was using a very 
> simple array. What type of array data did you use? I think I'm missing 
> something.
>
> I just did this:
>
>   put the weekdayNames into tDataA
>   split tDataA by cr
>   simpleSortNumberedArray tDataA, "descending,text"
>
What you're missing is that this (simpleSortNumberedArray) is only 
intended for "numbered array"s (which LC is calling "sequences" in some 
places); i.e. an array where the (top-level) keys are all consecutive 
integers, from 1 .... n

Also, the pSortkeys should be a number of comma-separated items, each of 
which consists of a key by which you want to sort the array followed 
optionally by an order and type.

So you might do something like :

> on mouseup
>    local tCounter, tDataA
>
>    repeat for each line L in the weekdayNames
>       add 1 to tCounter
>       put L into tDataA[tCounter]["dayname"]
>       put the number of chars in L into tDataA[tCounter]["charcount"]
>    end repeat
>
>    -- sorts ascending by name (i.e. F, M, Sa, Su, Th, Tu, W)
>    simpleSortNumberedArray tDataA, "dayname"
>    repeat with I = 1 to 7
>       put tDataA[I]["charcount"] && tDataA[I]["dayname"] & CR after msg
>    end repeat
>
>    put "---------" &CR after msg
>
>    -- sorts descending numeric by number of characters in name
>    --  NB within each char count value, they remain in alphabetical 
> order of name
>    simpleSortNumberedArray tDataA, "charcount numeric descending"
>    repeat with I = 1 to 7
>       put tDataA[I]["charcount"] && tDataA[I]["dayname"] & CR after msg
>    end repeat
> end mouseup
and get as output

> 6 Friday
> 6 Monday
> 8 Saturday
> 6 Sunday
> 8 Thursday
> 7 Tuesday
> 9 Wednesday
> ---------
> 9 Wednesday
> 8 Saturday
> 8 Thursday
> 7 Tuesday
> 6 Friday
> 6 Monday
> 6 Sunday

So - it would be worth adding a check that the array passed in is indeed 
a sequence, at the start of simpleSortNumberedArray:

if NOT (pArrayDataA is an array AND \
            item 2 of extents(pArrayDataA) is the number of elements in 
pArrayDataA) then \
                  return pArrayData

I'm now going to add this to my personal library, but I'll rename it to

     seqSortMultipleKeys

Alex.