Invoking return through a function?

[Rustom Mody]

On Sunday, October 29, 2017 at 9:52:01 PM UTC+5:30, Rick Johnson wrote:
> On Sunday, October 29, 2017 at 9:19:03 AM UTC-5, Alberto Riva wrote:

> > In a language like Lisp
> 
> Python is nothing like Lisp, and for good reason! Sure, we
> have a few lispers and functional fanboys who hang around
> here, and sometimes Rustom can get a little preachy about
> FP, but mostly, we tolerate the fanboyism -- so long as it's
> not rabid fanboyism.

Rick's personal comments are one of the standard entertainments of this list. Enjoy!

The comments on FP are more problematic:

- These misconceptions are more widespread than just Rick
- They are right enough to be hard to refute
- And wrong enough to cause confusion and misdirection
- And irrelevant to (threads like) this one

My super-short rejoiner to the FP-irrelevancy is:
«If there is one key takeaway from functional programming maybe it should be: "Truth is a function of time" »

In more detail:
- Lisp (1960)  was the second functional language; its predecessor was something called Formula Translator — usually shortened to Fortran (c. 1957)
- By the late 80s, many FPers had begun regard Lisp as a setback for functional programming. [Dont get me wrong: Ive enjoyed Scheme more than any other 
programming language. Its just that conflating Lisp and FP is an error (in 2017)]

More historical details at http://blog.languager.org/2015/04/cs-history-1.html and sequel

At a more conceptual level, people dont get that there are two dimensions
- the apply-lambda axis — usually called functional programming
- the eval-quote axis — which has precious little to do with FP (and is more relevant to your question)

These two dimensions of power uniquely coincide in Lisp (Scheme).

As you correctly (almost) point out
- Python is very much a lisp… its semantic under-belly
- However, syntactically its more like C/Java etc in the sense of having a rigid 
fixed-at-language-design-time syntax

More at http://blog.languager.org/2013/08/applying-si-on-sicp.html

For a question like macros (syntax-extensions) that sits between the two your
question is interesting and I am not sure I know how to do it…
I remember seeing something about this recently but my google-foo is failing me 
at the moment

However I would look at
- PEP 263 https://www.python.org/dev/peps/pep-0263/ — Source Code Encodings…
- Hooking into the codec module https://docs.python.org/3/library/codecs.html
- hooking into ast module https://docs.python.org/3/library/ast.html

An old attempt in this direction: http://code.activestate.com/recipes/546539/

You've already got the moral-hi-horse guys giving you the dope of why this is evil. Swallow if you like. My own lightweight
suggestion would be that the natural pythonic way of unstructured exit is exceptions. Not as succinct as a tailormade syntax extension. But good enough IMHO

PS I personally would be interested if you get this (syntax extension) running