that's an often repeated misconception about lisps.
lisps are pretty good at low-level programming, but then you'll need to make some compromises like abandoning the reliance on the GC and managing memory manually (which is still a lot easier than in other languages due to the metaprogramming capabilities).
there are lisps that can compile themselves to machine code in 2-4000 LoC altogether (i.e. compiler and assembler included; https://github.com/attila-lendvai/maru).
i'm not saying that there are lisp-based solutions that are ready for use in the industry. what i'm saying is that the lisp langauge is not at all an obstacle for memory-limited and/or real-time programs. it's just that few people use them, especially in those fields.
and there are interesting experiments for direct compilation, too:
BIT: A Very Compact #Scheme System for #Microcontrollers (#lisp #embedded)
http://www.iro.umontreal.ca/~feeley/papers/DubeFeeleyHOSC05....
"We demonstrate that with this system it is clearly possible to run realistic Scheme programs on a microcontroller with as little as 3 to 4 KB of RAM. Programs that access the whole Scheme library require only 13 KB of ROM."
"Many of the techniques [...] are part of the Scheme and Lisp implementation folklore. [...] We cite relevant previous work for the less well known implementation techniques."
People always point out this as a failure, when it is the contrary.
A programming language being managed doesn't mean we need to close the door to any other kind of resource management.
Unless it is something hard real time, and there are options there as well, we get to enjoy the productivity of high level programming, while at the same time having the tools at our disposal to do low level systems stuff, without having to mix languages.
lisps are pretty good at low-level programming, but then you'll need to make some compromises like abandoning the reliance on the GC and managing memory manually (which is still a lot easier than in other languages due to the metaprogramming capabilities).
there are lisps that can compile themselves to machine code in 2-4000 LoC altogether (i.e. compiler and assembler included; https://github.com/attila-lendvai/maru).
i'm not saying that there are lisp-based solutions that are ready for use in the industry. what i'm saying is that the lisp langauge is not at all an obstacle for memory-limited and/or real-time programs. it's just that few people use them, especially in those fields.
e.g. i'd easily prefer a lisp to put together a specialized byte-code interpreter to shrink firmware size for small embedded devices (e.g. for a radio https://github.com/armel/uv-k5-firmware-custom/discussions/4...).
and there are interesting experiments for direct compilation, too:
BIT: A Very Compact #Scheme System for #Microcontrollers (#lisp #embedded) http://www.iro.umontreal.ca/~feeley/papers/DubeFeeleyHOSC05.... "We demonstrate that with this system it is clearly possible to run realistic Scheme programs on a microcontroller with as little as 3 to 4 KB of RAM. Programs that access the whole Scheme library require only 13 KB of ROM." "Many of the techniques [...] are part of the Scheme and Lisp implementation folklore. [...] We cite relevant previous work for the less well known implementation techniques."
BIT inspired PICOBIT (last changed in 2015): https://github.com/stamourv/picobit racket (only a .so into an already running VM): http://download.racket-lang.org/docs/5.1.3/html/raco/ext.htm... scheme: gambit, chicken