This is a generic framework for generating output from a Cap'n proto schema file.
Based a little on how Clang's ASTVisitor works, except it uses virtual methods because I was too lazy to do the 'curiously repeating template' trick to save a vtable, since schemas tend not to be so big or so often parsed that performance of vtables in the visitor class would make much difference to anybody.
Basically, given a schema file, the header will load it into a schemaLoader instance. Every traversal method calls a pre_visit and a post_visit method and traverses into any known internal data. Returning true from pre_visit and some post_visit methods will skip the current data.
Traversal starts off like so:
traverse_file(Schema fileSchema)
pre_visit_file
traverse_nested_decls(fileSchema)
pre_visit_nested_decls
for (decl : schema.getProto().getNestedNodes())
pre_visit_decl
switch (schema::Node)
STRUCT: traverse_struct_decl(schema, decl)
ENUM: traverse_enum_decl(schema, decl)
...
post_visit_decl
post_visit_nested_decls
post_visit_fileLook in generic.h for the listing of methods and the parameters they take, as well as the traversal tree.
One thing to note is that the nested declarations are always traversed first, so they don't conflict with anything stored for the post_visit methods.
Included is a reference implementation of dealing with JSON. It uses rapidjson to handle outputting with commas in the right place, and it helped in development when DeathHandler gave stack traces for where the JSON would have been malformed, but instead raised exceptions.
- capnproto: https://github.com/kentonv/capnproto
- ./configure --prefix=$PWD/build && make -j8 && make install
- DeathHandler: https://github.com/vmarkovtsev/DeathHandler
- rapidjson: https://github.com/miloyip/rapidjson
- For the json reference implementation only.
- For using doit and/or cog:
- pip install -r requirements.txt