This is an a quick s-expression parser in a single file which runs correctly for the example supplied in the test. It uses recursions to tokenize and look forward for delimiters. For every token, it prints its data type (Integer, Float, Date, Atomic) and corresponding value. This is by no means a perfect implementation, but considering the amount of time given, it should be acceptable. A perfect implementation would require a Full recursive decent parser and lexical analyser for LISP syntax If I had enough time, I would use Flex & Bison to perfectly cover all the corner cases.
We rely on a simple makefile to compile the binary for the s-expression.
for your hosted compiler use : make build
- Getting an image with cross compilation tools. This will come with arm-linux-gnueabi
docker pull ev3dev/debian-stretch-cross - Giving it a tagname
docker tag ev3dev/debian-stretch-cross cross_env - Mounting the current directory project into the container
docker run --rm -it -v `pwd`:/var/ghgsat -w /var/ghgsat cross_env - Cross Compiling for arm
make build-cross will produce a an arm ELF file - In order to verify the output :
readelf -h bin/sexpr - Try the binary in Emulation with qemu :
qemu-arm bin/sexpr test/example.sexp - Try it natively :
scp bin/sexpr username@host:/your_path and run it there