Hi,
I was cutting and pasting some code from recent forum emails ("Interesting
Quora Problem") when I encountered a sequence that reliably crashes the
interpreter.
It goes like this:
4!:55 <'digits'
1
digits
|value error: digits
F=: {{(#~ 0=x|]);(10*y)+&.> (<>:i.9) (-. digits) &.> y}}
N1=: 1+i.9
F=: {{(#~ 0=x|]);(10*y)+&.> (<y) (-. digits) &.> y}}
9 F 8 F 7 F 6 F 5 F 4 F 3 F 2 F N1
|value error: digits
| (#~0=x|]);(10*y)+&.>(<y) (-.digits)&.>y
|F[:0]
Look at the stack:
13!:1''
|value error
* (#~0=x|]);(10*y)+&.>(<y) (-.digits)&.>y
|F[:0]
| 9 F 8 F 7 F 6 F 5 F 4 F 3 F 2 F N1
Cut back the stack:
dbr 1 [ dbr 0 NB. 13!:19''
|value error: F
| (#~0=x|]);(10*y)+&.>(<y)(-. digits)&.>y
|F[:0]
Cut back the stack again and crash:
dbr 1 [ dbr 0 NB. 13!:19''
Process shell<1> exited abnormally with code 5
This is on Windows 10 for JVERSION
Engine: j9.5.0-beta5/j64avx2/windows
Build: commercial/2023-07-31T00:44:14/clang-15-0-7/SLEEF=1
Library: 9.5.3
Platform: Win 64
Installer: j9.5 install
InstallPath: c:/pgm/j9.5
Contact: www.jsoftware.com
--
Devon McCormick, CFA
Quantitative Consultant
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