[Web-SIG] Sketching a WSGI 2-to-1 adapter with greenlets

[Ian Bicking]

On Fri, Sep 18, 2009 at 5:07 PM, P.J. Eby <pje at telecommunity.com> wrote:
> On his blog, Graham mentioned some skepticism about skipping WSGI 1.1 and
> going straight to 2.0, due to concern that people using write() would need
> to make major code changes to go to WSGI 2.0.

I'm not entirely clear why this is such a big deal.  Here's how I'd
implement a WSGI 2 wrapper around a WSGI 1 app:

def wsgi1to2(app):
    def new_app(environ):
        written = []
        status_headers = []
        def start_response(status, headers, exc_info=None):
            if exc_info is not None:
                raise exc_info[0], exc_info[1], exc_info[2]
            status_headers[:] = [status, headers]
            return written.append
        app_iter = app(environ, start_response)
        if not status_headers:
            app_iter = iter(app_iter)
            written.append(app_iter.next())
            assert status_headers
        if written:
            app_iter = itertools.chain(written, app_iter)
        return status_headers[0], status_headers[1], app_iter


What's wrong with this simpler approach to the conversion?


-- 
Ian Bicking  |  http://blog.ianbicking.org  |  http://topplabs.org/civichacker