* Cannot have an array as an input to a function
* Cannot return an array from a function
* Meta-programming or pointers are only (barely) available in gawk
* There is an `@include` statement for `gawk` that is not part of POSIX, and there is no name spacing involved.
* Functions names can only exist in the global name space
There are some reasons somebody felt an urge to create perl... Still loving awk, and using it every day for text processing jobs.
Larry Wall (creator of Perl) says something pretty close to that here[1]:
"I was too lazy to do it in awk because it would have been hard to get awk to jump through the hoops I was wanting it to jump through. I was too impatient to wait for awk to finish because it was so slow. And finally, I had the hubris to think I could do better."
http://cahighways.org/wordpress/?p=8019
http://ieeexplore.ieee.org/document/213253/
BLACKER's heavy lifting in security was done by high-assurance kernel called GEMSOS:
http://www.cse.psu.edu/~trj1/cse443-s12/docs/ch6.pdf
It was a classified work for TRW whose details took a long time to get released. Might be why he rarely mentioned the BLACKER project in its origins. Possibly trying to obfuscate it a bit to avoid breaking laws.