C++ code generation with Python

Question

Can anyone point me to some documentation on how to write scripts in Python (or Perl or any other Linux friendly script language) that generate C++ code from XML or py files from the command line. I'd like to be able to write up some xml files and then run a shell command that reads these files and generates .h files with fully inlined functions, e.g. streaming operators, constructors, etc.

Answer 1

If you want to do this simply with just standard Python stuff you might try making template files that use the Python 3 style string formatting. For example, a class template might look something like this:

{className}::{className}()
{{
}}

{className}::~{className}()
{{
}}

{className}::{className}(const {className}& other)
{{
}}

{className}& {className}::operator=(const {className}& other)
{{
    return *this;
}}

Then your Python code is super simple:

d = {}
d['className'] = 'MyCPlusPlusClassName'
with open(yourTemplateFile, 'r') as ftemp:
    templateString = ftemp.read()
with open(generatedFile, 'w') as f:
    f.write(templateString.format(**d))

Of course you can add lots of other fields alongside 'className' using the same trick. If you don't need stuff like conditional code generation you can get a lot of mileage out of something this simple.

Answer 2

I'm afraid you will not find an already-built in solution that takes your particular xml or python files and transforms them onto your required output "out of the box".

You will have to implement the parsing, the data treatment and output yourself. Not all by yourself, though; here are some pointers regarding the parsing and output.

Python comes with 2 different XML parsers (SAX and DOM -scroll down to see some examples). You will have to use one of them in order to read the source files.

For generating the output more easily, you can probably use a templating library, such as StringTemplate, or just generate the code manually, if it's small.

Answer 3

You could take a look at Shedskin, a project that generates C++ code from Python code.

Depending on what your reasons are, it may be a little pointless as Satanicpuppy pointed out.