#596 SHOW does not show the ORIGIN of an array

[DanielAjoy]

In version 8.3.2 these two show the same thing:

show (array 3 0)
{[] [] []}
show (array 3)
{[] [] []}

was expecting

show (array 3 0)
{[] [] []}@0

Otherwise, I don't know a way to write arrays to files, while preserving their ORIGIN information

The Help concerning ARRAY mentions:

FMSLogo has a special syntax for creating arrays and specifying its members at the same time. Arrays are delimited by curly braces and the origin can be optionally specified by appending an @ character after the closing curly brace, followed by the origin. For example, {a b c}@0 creates an array with three items and an origin of 0. PRINT and friends render arrays using the same syntax.

However:

print (array 3 0)
{[] [] []}

[David Costanzo]

This looks like a doc bug to me. UCBLogo 6.2.3 has the same behavior as FMSLogo 8.3.2. The UCBLogo documentation for ARRAY has different wording

    outputs an array of "size" members (must be a positive integer),
    each of which initially is an empty list.  Array members can be
    selected with ITEM and changed with SETITEM.  The first member of
    the array is member number 1 unless an "origin" input (must be an
    integer) is given, in which case the first member of the array has
    that number as its index.  (Typically 0 is used as the origin if
    anything.)  Arrays are printed by PRINT and friends, and can be
    typed in, inside curly braces; indicate an origin with {a b c}@0.

This behavior looks intentional in the source code. The output of PRINT and SHOW are intended to be shown to people, not used for preserving a workspace, so they don't show things like backslashes. Brian must have felt that the origin was similarly unimportant, only including it if you're using a workspace printing procedure. From print.cpp

    // print the origin when printing a workspace.
    if (print_backslashes && (getarrorg(nd) != 1))
    {
        wchar_t origin[32];
        swprintf(origin, ARRAYSIZE(origin), L"@%d", getarrorg(nd));
        print_string(strm, encoding, type, origin);
    }

Daniel writes:

Otherwise, I don't know a way to write arrays to files, while preserving their ORIGIN information

SAVE, PO, PONS, and similar commands use the origin-preserving code path, so if you save a workspace with a command that's designed for saving workspaces, the origin of array variables will be preserved. If you're writing arrays to a file and you're defining your own file format, you can also include the origin when you print the array with WORD "@ FIRST :array

[DanielAjoy]

that makes sense.

[David Costanzo]

I have committed [r6152], which documents that PRINT doesn't show an array's origin, or a word's backslashes or vertical bars. The documentation for SHOW still says it mostly behaves like PRINT. This will be included in the manual for FMSLogo 8.5.0.