C＃3.0和lambdas [英] C#3.0 and lambdas
问题描述
在Slashdot上有一个关于未来C＃3.0的讨论：
http://developers.slashdot.org/devel...?tid=109&tid=8
http://msdn.microsoft.com/vcsharp/future/
有许多不同之处，但它看起来更像Python：
http://download.microsoft.com/downlo...cification.doc
我非常喜欢lambda sintax。如果只有一个参数，则可以省略
括号。如果没有
参数，则需要它们。声明正文允许lambda做任何事情。
x => x + 1表达主体
x => {return x + 1;声明正文
（x，y）=> x * y多个参数
（）=> Console.WriteLine（）没有参数
语法看起来不错，但对于python，Statement body语法可以
成为一个问题。
再见，
熊宝宝
On Slashdot there is a discussion about the future C#3.0:
http://developers.slashdot.org/devel...?tid=109&tid=8
http://msdn.microsoft.com/vcsharp/future/
There are many differences, but it looks a bit more like Python:
http://download.microsoft.com/downlo...cification.doc
I like the lambda sintax enough. If there is a single parameter the
parentheses may be omitted. They are required if there aren''t
parameters. The statement body allows the lambda to do anything.
x => x + 1 Expression body
x => { return x + 1; } Statement body
(x, y) => x * y Multiple parameters
() => Console.WriteLine() No parameters
The syntax seems nice, but for python the "Statement body" syntax can
be a problem.
Bye,
bearophile
推荐答案
是*********** *@lycos.com 写道：
be************@lycos.com wrote:
在Slashdot上有一个关于未来C＃3.0的讨论：
http：//developers.slashdot.org/devel ... ？tid = 109& tid = 8
http://msdn.microsoft.com/vcsharp/future/
"扩展程序可构建组合API，
具有相同的表达能力在诸如关系数据库和XML之类的域中查询语言。
有许多不同之处，但它看起来更像Python：
http://download.microsoft.com/downlo...cification.doc
On Slashdot there is a discussion about the future C#3.0:
http://developers.slashdot.org/devel...?tid=109&tid=8
http://msdn.microsoft.com/vcsharp/future/
"The extensions enable construction of compositional APIs that
have equal expressive power of query languages in domains such
as relational databases and XML."
There are many differences, but it looks a bit more like Python:
http://download.microsoft.com/downlo...cification.doc
同时，在python-dev土地上：
是否有人真正依附于嵌套元组函数参数; ''def
fxn（（a，b））：打印a，b''？ /.../
如果他们离开，有人真的会非常适合吗？我愿意写一个PEP，以便在2.6中删除它们，如果
人为它而弃用它。
< / F>
meanwhile, over in python-dev land:
"Is anyone truly attached to nested tuple function parameters; ''def
fxn((a,b)): print a,b''? /.../
Would anyone really throw a huge fit if they went away? I am willing
to write a PEP for their removal in 2.6 with a deprecation in 2.5 if
people are up for it."
</F>
您好，
"是否有人真正依附于嵌套元组函数参数; ''def
fxn（（a，b））：打印a，b''？ /.../
如果他们离开，有人真的会非常适合吗？我愿意写一个PEP，以便在2.6中删除它们，如果有人愿意，可以弃用2.5。
"Is anyone truly attached to nested tuple function parameters; ''def
fxn((a,b)): print a,b''? /.../
Would anyone really throw a huge fit if they went away? I am willing
to write a PEP for their removal in 2.6 with a deprecation in 2.5 if
people are up for it."
首先我错过了def，并且想哦，不要删除它
有时候我会将一个元组传递给我的函数。
但是我看到了 DEF"关键字和实现我从来没有使用过这样的函数语法。
因此，在一行（我的邮件程序截断它）：
def fxn（（a，b））：打印a，b''
要删除，而不是：
''fxn（（a，b）''函数调用
我可以删除。
bye by Wolfgang
First I missed the def and thought "Oh no don''t remove it
sometimes I pass a tuple to my functions".
But the I saw the "def" keyword and realized I never
used such a function syntax.
So, in one line (my mailer truncated it):
def fxn((a,b)): print a,b''
for removal, not:
''fxn((a,b)'' function calls
I''m ok with removal.
bye by Wolfgang
Fredrik Lundh schreef：
Fredrik Lundh schreef:
同时，在python-dev土地上：
是否有人真正依附于嵌套元组函数参数;''def
fxn（（a，b））：打印a，b''？/.../
如果他们离开，有人真的会非常适合吗？我愿意
写一个PEP，在2.6中删除，如果有人愿意，可以弃用2.5。
meanwhile, over in python-dev land:
"Is anyone truly attached to nested tuple function parameters; ''def
fxn((a,b)): print a,b''? /.../
Would anyone really throw a huge fit if they went away? I am willing
to write a PEP for their removal in 2.6 with a deprecation in 2.5 if
people are up for it."
我不喜欢看到它消失了。我喜欢能够写b
，例如：
def drawline（（x1，y1），（x2，y2）） ：
＃d原始从x1，y1到x2，y2的行
foo（x1，y1）
bar（x2，y2）
而不是
def drawline（p1，p2）：
x1，y1 = p1
x2，y2 = p2
＃从x1，y1到x2画一条线，y2
foo（x1，y1）
bar（x2，y2）
或
def drawline（p1，p2）：
＃从p1 [0]画一条线，p1 [ 1]到p2 [0]，p2 [1]
foo（p1 [0]，p1 [1]）
bar（p2 [0]，p2 [1 ]）
-
如果我能够进一步看到，那只是因为我站在了巨人的肩膀上。 - Isaac Newton
Roel Schroeven
I for one would not like to see that disappear. I like being able to
write, for example:
def drawline((x1, y1), (x2, y2)):
# draw a line from x1, y1 to x2, y2
foo(x1, y1)
bar(x2, y2)
instead of
def drawline(p1, p2):
x1, y1 = p1
x2, y2 = p2
# draw a line from x1, y1 to x2, y2
foo(x1, y1)
bar(x2, y2)
or
def drawline(p1, p2):
# draw a line from p1[0], p1[1] to p2[0], p2[1]
foo(p1[0], p1[1])
bar(p2[0], p2[1])
--
If I have been able to see further, it was only because I stood
on the shoulders of giants. -- Isaac Newton
Roel Schroeven
这篇关于C＃3.0和lambdas的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
