how I processed these files

build the ppx using dune

ran it
```
find -name \*.ml -exec ./_build/default/.ppx/1977eb4d6c4f6ad3b912f65add506a08/ppx.exe  {} > /dev/null \;
 find -name \*.str > files.txt
 tar -cf json.tar -T files.txt 
 mkdir ~/2023/12/28/ppxlib/ocaml-opam-ppxlib-json-ast/dune/
 tar -xf json.tar -C ~/2023/12/28/ppxlib/ocaml-opam-ppxlib-json-ast/dune/
```