block/lambda

iu2 israelu at elbit.co.il
Mon Jul 28 22:12:26 CEST 2008


On Jul 28, 10:06 pm, iu2 <isra... at elbit.co.il> wrote:
> Hi,
>
> Playing with imitating lambdas and ruby blocks in Python, I came up
> with a very simple construct, for example:
>
> import compiler
>
> def dotimes(i, code):
>     for i in range(i):
>         exec code
>
> dotimes(5, '''
> for j in range(i):
>         print j,
> print
> ''', '<string>', 'exec')
>
> This will print
> 0
> 0 1
> 0 1 2
> 0 1 2 3
>
> A more efficient code would probably be
>
> dotimes(5, compiler.compile('''
> for j in range(i):
>         print j,
> print
> ''', '<string>', 'exec'))
>
> which is, to my understanding, exactly what a ruby block is.
>
> But the actual "discovery" here, is that the triple quote - ''' -
> makes a syntax for block passing. Having a code editor that keeps
> colorizing what's inside the quotes like a normal code would make it
> easier to maintain.
>
> Is it possible to grant Python another syntactic mark, similar to
> triple quotes, that will actually make the enclosed code a compiled
> code, or an anonymous function?
>
> I know that anonymous functions (long lambdas...) are not on the road
> map. But I ask this because, as I understand it, the triple quote
> actually presents a syntax for it.
> Isn't it actually a matter of taking the triple-quotes a little bit
> further?
>
> Thanks

There is a mistake in my first example, the code is, of course:
dotimes(5, '''
for j in range(i):
        print j,
print
''')

Sorry...



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