1. but what about ( t * s + t / s )? temp var always keep in memory. (should not reduce ( t + s ) to ( 2 * x ) since x, y may not a number. any operator here should be conside as independent function. )

2. try convert this to the lambda form: (x+y as t, x-y as s)(t * s as u, t/s as v)(u << v as p, u>>v as q) p ** q sorry, here should be :

在 2011年7月26日 上午2:56，海韵 <lyricconch@gmail.com> 写道： try convert this to the lambda form: R = lamba x, y: (x+y as t, x-y as s)(t * s as u, t/s as v)(u << v as p, u>>v as q) p ** q using "as" can make lambda expression more graceful.

In runtime: lambda = MAKE_FUNCTION/MAKE_CLOSURE = PyFunction_New lambda call = CALL_FUNCTION = PyFrame_New + PyEval_EvalFrameEx all of them are heavy, (you can check the source code)

but: as = PyCell_New as enter = SETUP_FINALLY = PyFrame_BlockSetup as leave = END_FINALLY = PyFrame_BlockPop which is much much much more more more cheaper than above.

2011/7/26 Bruce Leban <bruce@leapyear.org>:

...

On Mon, Jul 25, 2011 at 9:50 AM, 海韵 <lyricconch@gmail.com> wrote:

...

Dupilcate K is used only for describe the scope rule. Advantage:

1. the same grammer, the same behave "t" of """(x+y as t, x-y as s) t * s + s + t""" is only valid in the expression which require just as "e" of """except ... as e""" only live in the suite which it belongs

2. readability includes laconic a = (x+y as t, x-y as s) t * s + s + t it doesnt break thinking. from left to right, people finish thinking inplace. temp var will not keep in memory, people can forget them since they are not valid outside the expression. everything is clean. t, s = x+y, x-y a = t * s + s + t in this case, thinking is break and temp var keep in memory, people should take some care about it (for example, in nested loop)

(x + y) * (x - y) + 2 * x is IMHO more readable - especially note the absence of y in the third term.

...

3. this enchant the "lambda" syntax list.sort(key = lambda p: (sqrt(p.x**2+p.y**2) as r) r**2+ A*r + B)

I don't know what "enchant" means here, but you can do this if you want: list.sort(key = lambda p: (lambda r: r**2 + A*r + B) (sqrt(p.x**2+p.y**2))) I'm not recommending that as I think it would be more readable to name that function so that it would be more clear why you're using that function as the sort key. But, to me, this example does not justify new syntax. --- Bruce

1. but what about ( t * s + t / s )? temp var always keep in memory. (should not reduce ( t + s ) to ( 2 * x ) since x, y may not a number. any operator here should be conside as independent function. )

2. try convert this to the lambda form: (x+y as t, x-y as s)(t * s as u, t/s as v)(u << v as p, u>>v as q) p ** q sorry, here should be :

在 2011年7月26日 上午2:56，海韵 <lyricconch@gmail.com> 写道： try convert this to the lambda form: R = lamba x, y: (x+y as t, x-y as s)(t * s as u, t/s as v)(u << v as p, u>>v as q) p ** q using "as" can make lambda expression more graceful.

In runtime: lambda = MAKE_FUNCTION/MAKE_CLOSURE = PyFunction_New lambda call = CALL_FUNCTION = PyFrame_New + PyEval_EvalFrameEx all of them are heavy, (you can check the source code)

but: as = PyCell_New as enter = SETUP_FINALLY = PyFrame_BlockSetup as leave = END_FINALLY = PyFrame_BlockPop which is much much much more more more cheaper than above.

2011/7/26 Bruce Leban <bruce@leapyear.org>:

...

On Mon, Jul 25, 2011 at 9:50 AM, 海韵 <lyricconch@gmail.com> wrote:

...

Dupilcate K is used only for describe the scope rule. Advantage:

1. the same grammer, the same behave "t" of """(x+y as t, x-y as s) t * s + s + t""" is only valid in the expression which require just as "e" of """except ... as e""" only live in the suite which it belongs

2. readability includes laconic a = (x+y as t, x-y as s) t * s + s + t it doesnt break thinking. from left to right, people finish thinking inplace. temp var will not keep in memory, people can forget them since they are not valid outside the expression. everything is clean. t, s = x+y, x-y a = t * s + s + t in this case, thinking is break and temp var keep in memory, people should take some care about it (for example, in nested loop)

(x + y) * (x - y) + 2 * x is IMHO more readable - especially note the absence of y in the third term.

...

3. this enchant the "lambda" syntax list.sort(key = lambda p: (sqrt(p.x**2+p.y**2) as r) r**2+ A*r + B)

I don't know what "enchant" means here, but you can do this if you want: list.sort(key = lambda p: (lambda r: r**2 + A*r + B) (sqrt(p.x**2+p.y**2))) I'm not recommending that as I think it would be more readable to name that function so that it would be more clear why you're using that function as the sort key. But, to me, this example does not justify new syntax. --- Bruce