Hi Colin,
thanks, see below...
Best Regards,
Jürgen
On 5/3/20 2:13 AM, Colin Verrilli
wrote:
I was playing around with using empty arguments with
functions to see what happens.
This one seems to make sense
↑ (0↑(1 2)(3 4)),¨(0↑(1 2 3)(4 5 6))
0 0 0 0 0
Yes. The prototype (0 0) of (1 2)(3 4)) and the prototype (0 0 0) of
(1 2 3)(4 5 6) are
being concatenated to form the result.
This next one I'm not sure about. Theoretically, it should give
the same result as above, but maybe the behavior is different
for defined functions.
↑ (0↑(1 2)(3 4))f¨(0↑(1 2 3)(4 5 6))
0 0 0
⎕cr 'f'
z←l f r
z←l,r
The APL2 LRM makes a big deal about each function having a
corresponding "fill function" that is used when the arguments
are empty. It's not clear about what happens with defined
functions.
defined functions (and also non-scalar primitives) handle empty
arguments different
from scalar functions. They have to because otherwise you could not
write a defined
function that handles empty arguments
This one should probably be a length error or something, but I
get a failure.
↑ (0↑(1 2)(3 4))=¨(0↑(1 2 3)(4 5 6))
Correct. You now get a length error (
SVN 1278).
==============================================================================
Assertion failed: A->same_shape(*B)
in Function: eval_fill_AB
in file: ScalarFunction.cc:707
Call stack:
----------------------------------------
-- Stack trace at ScalarFunction.cc:707
----------------------------------------
0x43195865 __libc_start_main
0x80973E0 main
0x8200B65 Workspace::immediate_execution(bool)
0x80F1A4D Command::process_line()
0x80F149E Command::do_APL_expression(UCS_string&)
0x80F0C25 Command::finish_context()
0x80FAB54 Executable::execute_body() const
0x81B10DD StateIndicator::run()
0x812CD9C Prefix::reduce_statements()
0x812C31E Prefix::reduce_A_F_B_()
0x8101FCC DerivedFunction::eval_AB(Value_P, Value_P)
0x80C5B26 Bif_OPER1_EACH::eval_ALB(Value_P,
Token&, Value_P)
0x81A2ACC ScalarFunction::eval_fill_AB(Value_P,
Value_P)
0x80AC487 do_Assert(char const*, char const*, char
const*, int)
========================================
Colin