xo-expression2/xo-facet

xo-facet

Codegen

To scaffold a new facet Foo we need several c++ classes

• AFoo abstract FOMO interface, with opaque data pointer
• IFoo_Any variant placeholder, all methods terminate
• IFoo_Xfer template, delegates methods to a separate implementation class
• RFoo template, inherits from a 2x-wide fat pointer (iface+data).

These classes all have parallel methods Can generate these as follows:

1. write xo-foo/idl/Foo.json5.

   Supply attributes:

   • mode :: string
   • includes :: [string]
   • namespace1 :: string
   • namespace2 :: string
   • facet :: string
   • detail_subdir :: string
   • brief :: string
   • using_doxygen :: bool
   • doc :: [string]
   • types :: [{name, doc, definition}]
   • const_methods :: [{name, doc, return_type, args, const, noexcept, attributes}]
   • nonconst_methods :: [{name, doc, return_type, args, const, noexcept, attributes}]

Example in xo-object2/idl/Sequence.json5

2. generate:

$ cd xo-foo
$ ../xo-facet/codegen/genfacet.py --input ./idl/Foo.json5 --output include/xo/foo2

Alternatively in xo-foo/CMakeLists.txt

xo_add_genfacet(
    TARGET xo-foo2-facet-foo
    FACET Foo
    INPUT idl/Foo.json5
    OUTPUT_HTTP_DIR include/xo/foo2
    OUTPUT_IMPL_SUBDIR detail
    OUTPUT_CPP_DIR src/foo2)

then generate with:

cmake --build path/to/build -- xo-foo2-facet-foo