[Bug-apl] QUAD QUOTE, QUAD PR and nested arrays

[Frederick Pitts]

Hello Juergen,

    In the interest of making Gnu APL as compatible as practical with
IBM APL2, please consider the following:

    The IBM APL2 quad quote prompt replacement facility supports the
prompt being a nested array.  I make that claim based on the APL code
for the parts inventory demo presented on page 100 of the IBM 'APL2
Programming: Guide'.  Please examine the 'menu' and 'input'
functions.  The prompt created by the 'menu' function is a nested
array.

    The Gnu APL quad quote prompt replacement facility only performs
replacement on primitive character arrays and leaves nested arrays
unchanged.  I make that assertion based on the attached 'TEST.apl'
which was created by lifting the first 5 lines (including header) of
the 'input' function from the parts inventory demo above and adding
code to exercise the function.

    If you run 'TEST.apl' and type 'FILL' (without the quotes) at the
two prompts, you should see

 CHOOSE PLACE FILL OR STOCK :  FILL
 CHOOSE PLACE FILL OR STOCK :  FILL
 CHOOSE PLACE FILL OR STOCK : FILL
FILL

The first two lines result from using a prompt generated with nested
array; the second two lines from a simple character array.

Regards,

Fred

TEST.apl
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