[Python-ideas] Python-ideas Digest, Vol 129, Issue 44

[王宣 赵]

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发件人: python-ideas-request at python.org
发送时间: 8月14日星期一 03:14
主题: Python-ideas Digest, Vol 129, Issue 44
收件人: python-ideas at python.org


Send Python-ideas mailing list submissions to python-ideas at python.org To subscribe or unsubscribe via the World Wide Web, visit https://mail.python.org/mailman/listinfo/python-ideas or, via email, send a message with subject or body 'help' to python-ideas-request at python.org You can reach the person managing the list at python-ideas-owner at python.org When replying, please edit your Subject line so it is more specific than "Re: Contents of Python-ideas digest..." Today's Topics: 1. How do you think about these language extensions? (?? ?) 2. Re: New PEP 550: Execution Context (Yury Selivanov) 3. Re: New PEP 550: Execution Context (Nathaniel Smith) ---------------------------------------------------------------------- Message: 1 Date: Sun, 13 Aug 2017 12:49:45 +0000 From: ?? ? To: "python-ideas at python.org" Subject: [Python-ideas] How do you think about these language extensions? Message-ID: Content-Type: text/plain; charset="iso-2022-jp" Hi all, I've just finished a language extension for CPython 3.6.x to support some additional grammars like Pattern Matching. And It's compatible with CPython. I'm looking for constructive advice, and I wonder if you will be interested in this one. ? the project address is https://github.com/thautwarm/flowpython) [https://avatars1.githubusercontent.com/u/22536460?v=4&s=400] thautwarm/flowpython github.com flowpython - tasty feature extensions for python(python3). Some examples here: # where syntax from math import pi r = 1 # the radius h = 10 # the height S = (2*S_top + S_side) where: S_top = pi*r**2 S_side = C * h where: C = 2*pi*r # lambda&curry : lambda x: lambda y: lambda z: ret where: ret = x+y ret -= z .x -> .y -> .z -> ret where: ret = x+y ret -= z as-with x def as y def as z def ret where: ret = x+y ret -= z # arrow transform (to avoid endless parentheses and try to be more readable. >> range(5) -> map(.x->x+2, _) -> list(_) >> [2,3,4,5,6] # pattern matching # use "condic" as keyword is for avoiding the conflictions against the standard libraries and packages from third party. "switch" and "match" both lead to conflictions. condic+(type) 1: case a:int => assert a == 1 and type(a) == 1 [>] case 0 => assert 1 > 0 [is not] case 1 => assert 1 is not 1 otherwise => print("nothing") condic+() [1,2,3]: case (a,*b)->b:list => sum(b) +[] case [] => print('empty list') +[==] case (a,b):(1,2) => print("the list is [1,2]") The grammars with more details and examples can be found in https://github.com/thautwarm/flowpython/wiki Does it interest you? If so, you can try it if you have CPython 3.6.x. pip install flowpython python -m flowpython -m enable/disable Here is an example to use flowpython, which gives the permutations of a sequence. from copy import deepcopy permutations = .seq -> seq_seq where: condic+[] seq: case (a, ) => seq_seq = [a,] case (a, b) => seq_seq = [[a,b],[b,a]] case (a,*b) => seq_seq = permutations(b) -> map(.x -> insertAll(x, a), _) -> sum(_, []) where: insertAll = . x, a -> ret where: ret = [ deepcopy(x) -> _.insert(i, a) or _ for i in (len(x) -> range(_+1)) ] If the object permutations are defined, try these codes in console: >> range(3) -> permutations(_) >> [[0, 1, 2], [1, 0, 2], [1, 2, 0], [0, 2, 1], [2, 0, 1], [2, 1, 0]] Does it seem to be interesting? Thanks, Thautwarm -------------- next part -------------- An HTML attachment was scrubbed... URL: ------------------------------ Message: 2 Date: Sun, 13 Aug 2017 14:44:24 -0400 From: Yury Selivanov To: Nick Coghlan Cc: Nathaniel Smith , "python-ideas at python.org" Subject: Re: [Python-ideas] New PEP 550: Execution Context Message-ID: Content-Type: text/plain; charset="UTF-8" I'll start a new thread to discuss is we want this specific semantics change soon (with some updates). Yury ------------------------------ Message: 3 Date: Sun, 13 Aug 2017 12:14:07 -0700 From: Nathaniel Smith To: Yury Selivanov Cc: Nick Coghlan , Python-Ideas Subject: Re: [Python-ideas] New PEP 550: Execution Context Message-ID: Content-Type: text/plain; charset="UTF-8" On Sun, Aug 13, 2017 at 9:57 AM, Yury Selivanov wrote: > 2. ContextItem.has(), ContextItem.get(), ContextItem.set(), > ContextItem.delete() -- pretty self-explanatory. It might make sense to simplify even further and declare that context items are initialized to None to start, and the only operations are set() and get(). And then get() can't fail, b/c there is no "value missing" state. -n -- Nathaniel J. Smith -- https://vorpus.org ------------------------------ Subject: Digest Footer _______________________________________________ Python-ideas mailing list Python-ideas at python.org https://mail.python.org/mailman/listinfo/python-ideas ------------------------------ End of Python-ideas Digest, Vol 129, Issue 44 *********************************************

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