LAMBDA IS IT USELESS?

[Suchandra Thapa]

EricIDLE <grayson-wilson at home.com> wrote:
>Ok well I dont quite grasp the Lambda concept heres an example.
[...]
>
>Isnt that easier??
>
>Or do I not get lambda?
>
>*NOTE ... I think its just a way to complicate things OR just a way to avoid
>typing the function name beacuse.... I dont know they are scared of the
>names they give them.

    The lambda can be  a way  to avoid the need to define and name trivial
functions that get used in only one place.  However, the lambda function
is a also a way to dynamically create functions as well as a way of
composing two functions together.  For example, suppose you need to
apply a scaling factor to a list but the scaling factor depends on 
user input.  In this case, with lambda you can do a with 
lambda x: x * s where the value of s depends on the user input.  Also, 
suppose you have two image filters and you want to create a new filter
that applies the first filter then the second one.  Then using lambda, 
you can just use lambda x: filter2(filter1(x)).  
    Incidentally, you can use lambda to do a bunch of different things including
reducing the number of parameters a function takes (currying).  E.g. 
suppose foo takes x, y, and z then lambda x, y:foo(x, y, 4) returns a function
that takes only two paramters.  
    Basically, think of lambda as a way of applying mathematical operations
like +, /, * as well as a few others to functions.

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	   		              |
Suchandra Thapa                       | "There are only two kinds of math . 
s-thapa-11 at NOSPAMalumni.uchicago.edu  | books. Those you cannot read beyond 
			              | the first sentence, and those you 
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			              |                     -C.N. Yang
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