[Bug-apl] Deal (?) reports assertion error rather than APL error message

[Frederick Pitts]

Hello Jürgen,

        Should GNU APL report an APL error message, say "DOMAIN ERROR",
rather then an assertion diagnostic for `¯1 ? 5'?  The reason I ask is
`3 ? ¯1' produces "DOMAIN ERROR".

        Details follow:

address@hidden $ apl -v
BUILDTAG:
---------
    Project:        GNU APL
    Version / SVN:  1.7 / 1022M
    Build Date:     2017-11-23 18:07:12 UTC
    Build OS:       Linux 4.13.13-300.fc27.x86_64 x86_64
    config.status:  'RATIONAL_NUMBERS_WANTED=yes'
'CORE_COUNT_WANTED=syl'
    Archive SVN:    989

address@hidden $ apl
      ¯1 ? 5

=======================================================================
=======
Assertion failed: items
in Function:      at
in file:          Simple_string.hh:286

Call stack:

----------------------------------------
-- Stack trace at Simple_string.hh:286
----------------------------------------
0x7F40C62DD03A __libc_start_main
0x448C25  main
0x5BB01D   Workspace::immediate_execution(bool)
0x49A424    Command::process_line()
0x49ABDD     Command::do_APL_expression(UCS_string&)
0x49A48F      Command::finish_context()
0x4A5658       Executable::execute_body() const
0x557350        StateIndicator::run()
0x4E9494         Prefix::reduce_statements()
0x4E6BAD          Prefix::reduce_END_B__()
0x557CAF           StateIndicator::statement_result(Token&, bool)
0x5B6D85            Value::print(std::ostream&) const
0x50A7DD             PrintBuffer::PrintBuffer(Value const&,
PrintContext const&, std::ostream*)
0x45B5E8              do_Assert(char const*, char const*, char const*,
int)
========================================

SI stack:

Depth:      0
Exec:       0xc3a1a0
Safe exec:  0
Pmode:      ◊  ¯1 ? 5
PC:         4 (5) RETURN_STATS
Stat:       ¯1 ? 5
err_code:   0x0


=======================================================================
=======


Regards,

Fred