[racket] Calculating cumulative sum of the list

:-) 


On Jan 22, 2015, at 9:20 PM, Neil Toronto wrote:

> Well, there is always the amazing math library. But somehow, the author of `math/base` forgot to include a `sums` function!
> 
> There *is* a `flvector-sums` in `math/flonum`, which operates only on flonums. If you can believe this, the documentation for that function even *gives example code* for computing cumulative sums!
> 
> Stupid git.
> 
> Neil ⊥
> 
> On 01/22/2015 07:35 PM, Matthias Felleisen wrote:
>> 
>> NOTE TO EVERYONE: The OP asked for "without usage of any libraries".
>> I am sure that sooner or later we will find a library so that we
>> can say (require lib/cumulative) cumulative-sum.
>> 
>> 
>> 
>> On Jan 22, 2015, at 7:16 PM, William James wrote:
>> 
>>> Here's a way using map-accum in Gauche.
>>> 
>>> (use gauche.collection)
>>> 
>>> (define (cumulative-sums xs)
>>>  (map-accum (lambda (x sum) (values (+ x sum) (+ x sum))) 0 xs))
>>> 
>>> (cumulative-sums '(1 3 5 7))
>>> ===>
>>> (1 4 9 16)
>>> 
>>> 
>>> --------------------------------------------
>>> On Thu, 1/22/15, Alexandr M <rus314 at gmail.com> wrote:
>>> 
>>> Subject: [racket] Calculating cumulative sum of the list
>>> To: users at racket-lang.org
>>> Date: Thursday, January 22, 2015, 7:53 AM
>>> 
>>> Hello,
>>> 
>>> I am trying to replicate functionality of this code in
>>> Python:
>>> 
>>> https://gist.github.com/m-blog/22b7c5d31b3839ffba50#file-cumsum-py
>>> 
>>> in Racket without usage of any libraries.
>>> 
>>> What would the most optimal / concise way to do it in
>>> Racket?
>>> 
>>> Thank you.
>>> 
>>> --
>>> Best regards,
>>> Alex
>>> 
>>> 
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