Re: def partial vs let partial

2016-12-01 Thread Timothy Baldridge 
It's because the value of the + is captured when the partial is created (or
when the var is implicitly derefed). The value of the var is implicitly
captured (via deref) at the point where it appears in the form.

It's a bit of a complex topic, but this blog post I wrote a few months ago
may help a bit:
http://blog.cognitect.com/blog/2016/9/15/works-on-my-machine-understanding-var-bindings-and-roots

On Thu, Dec 1, 2016 at 1:30 PM, Matthew Hamrick 
wrote:

> I'm confused by the following code.
> Could someone explain to me why the def-ed partial has different behavior
> to the letted one?
> This is especially confusing to me since the #() special form one works as
> I expect.
>
> (def sum-partial-def (partial reduce +))
>
> (let [sum-partial (partial reduce +)
>   sum-# #(reduce + %1)
>   nums [1 2 3 4]]
>   [(sum-partial-def nums)
>(reduce + nums)
>(sum-# nums)
>(sum-partial nums)]) ;; => [10 10 10 10]
>
> (with-redefs [+ (fn [a b]
>   (.add (.add (BigInteger. (str a))
>   (BigInteger. (str b)))
> (BigInteger/ONE)))]
>   (let [sum-partial (partial reduce +)
> sum-# #(reduce + %1)
> nums [1 2 3 4]]
> [(sum-partial-def nums)
>  (reduce + nums)
>  (sum-# nums)
>  (sum-partial nums)])) ;; => [10 13 13 13]
>
> Thanks,
> Matt
>
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Re: def partial vs let partial

2016-12-01 Thread Gary Trakhman 
Sum-partial-def gets the original + definition because it is evaluated
first, if you want late binding, try (partial reduce (var +)).

On Dec 1, 2016 4:05 PM, "Matthew Hamrick"  wrote:

> I'm confused by the following code.
> Could someone explain to me why the def-ed partial has different behavior
> to the letted one?
> This is especially confusing to me since the #() special form one works as
> I expect.
>
> (def sum-partial-def (partial reduce +))
>
> (let [sum-partial (partial reduce +)
>   sum-# #(reduce + %1)
>   nums [1 2 3 4]]
>   [(sum-partial-def nums)
>(reduce + nums)
>(sum-# nums)
>(sum-partial nums)]) ;; => [10 10 10 10]
>
> (with-redefs [+ (fn [a b]
>   (.add (.add (BigInteger. (str a))
>   (BigInteger. (str b)))
> (BigInteger/ONE)))]
>   (let [sum-partial (partial reduce +)
> sum-# #(reduce + %1)
> nums [1 2 3 4]]
> [(sum-partial-def nums)
>  (reduce + nums)
>  (sum-# nums)
>  (sum-partial nums)])) ;; => [10 13 13 13]
>
> Thanks,
> Matt
>
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def partial vs let partial

2016-12-01 Thread Matthew Hamrick 
I'm confused by the following code.
Could someone explain to me why the def-ed partial has different behavior 
to the letted one?
This is especially confusing to me since the #() special form one works as 
I expect.

(def sum-partial-def (partial reduce +))

(let [sum-partial (partial reduce +)
  sum-# #(reduce + %1)
  nums [1 2 3 4]]
  [(sum-partial-def nums)
   (reduce + nums)
   (sum-# nums)
   (sum-partial nums)]) ;; => [10 10 10 10]

(with-redefs [+ (fn [a b]
  (.add (.add (BigInteger. (str a))
  (BigInteger. (str b)))
(BigInteger/ONE)))]
  (let [sum-partial (partial reduce +)
sum-# #(reduce + %1)
nums [1 2 3 4]]
[(sum-partial-def nums)
 (reduce + nums)
 (sum-# nums)
 (sum-partial nums)])) ;; => [10 13 13 13]

Thanks,
Matt

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Re: Clojure as a first programming language?

2016-12-01 Thread Ryan Waters 
It's a question simply stated with an answer that depends on a lot of
things. And, as is often the case with the person giving an answer, without
asking other people I can only relate it to my own experiences with clojure
and programming in general.

The fun and freeing thing about clojure is the flexible ways it allows you
to program and think about programming challenges.  There's a number of
reasons that make this true.  Languages I've used in the past at times felt
like their design was limiting, usually in the form of making easy things
easy and hard things harder than necessary.  Maybe they provided too much
"help" and turned inner workings into a difficult-to-know black box, or
they provided concurrency building blocks without providing a safe
framework to prevent a novice programmer from shooting themselves in the
foot, or they were designed in such a way that locking in developer
mindshare was a primary motivator.  I don't think clojure has these
problems.

Diving into a new language requires good learning resources, particularly
in the ways you find most natural to use.  Are you self-sufficient?  Is
documentation enough or would it be faster and more useful to be able to
ask someone questions?  Do you have any higher education in programming?
Buy some clojure books and spend time with them.  The mailing list, IRC and
slack, et. al. can all be resources for specific questions but more general
questions (even this one) can be more difficult to answer.

Pick something you want to make and explore what different languages have
to offer and you'll naturally find one that resonates with you.  I love
clojure.  It's not perfect but it's still smarter than I am, which I
appreciate.  It rarely gets in my way.



On Thu, Dec 1, 2016 at 12:22 PM, Nur Azhar  wrote:

> Hi,
>
> it's almost 8 years later and I am going to ask these same question since
> it wasn't really answered
>
> Thanks for taking the time to read. I’m interested in trying out Clojure
>> for my first programming language--at least, the first programming language
>> in which I intend to commit myself to becoming proficient.
>> http://stackoverflow.com/questions/10509283/clojure-as-
>> a-first-programming-language
>>
> I hope someone replies
>
> On Tuesday, December 1, 2009 at 1:38:58 PM UTC+8, Towle wrote:
>>
>> Hi all,
>>
>> Thanks for taking the time to read my post. I'm interested to get some
>> opinions from experienced Clojure programmers on whether the language
>> would be a good first language to learn, or rather to learn in-depth.
>> I have minimal experienced with more common languages like Java, HTML,
>> and C++, but having the personality I do, felt compelled to shop
>> around a bit before choosing a first language to learn seriously on a
>> deep and intuitive level-- perhaps my odd notion of there being a
>> connection between a programmer and the first language s/he
>> understands on that high of a level. So after shopping around
>> thoroughly and picking up bits about on theoretical computer science
>> and the history of programming languages, I decided to pick up a Lisp;
>> I'm intrigued by the greater concept/idea behind the Lisp family of
>> languages.
>>
>> After a long while trying to figure out which of the Lisps would be a
>> good first choice, I stumbled across Clojure and immediately thought
>> it a brilliant idea, conceding of course that at my current level of
>> knowledge, I likely have no idea what a brilliant idea in computer
>> programming looks like. Regardless, it still feels brilliant.
>>
>> As I see it, among other features of the language, the idea of a Lisp
>> designed to be a capable choice for "real-world" code applications,
>> that is a Lisp which embodies the spirit of that family of languages
>> yet one which resolves many of the "practicality" complaints which
>> stand as hurdles on a Lisp's path to real-world use. For my situation,
>> that of a student who wants both a) to learn a first language I can
>> have a real, intellectual appreciation for and b) to begin the journey
>> to "expertise" in a language it would be practical to code web
>> applications in.
>>
>> So, Clojure programmers, am I wrong? Should I pass on Clojure in favor
>> of another langauge? Or learn Common Lisp or Scheme first, then try my
>> hand at Clojure? Am I mistaken for a different reason? Or perhaps
>> there are some criteria I should consider before diving in?
>>
>> Thanks in advance, and again for taking the time to read.
>> --Towle
>>
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Re: Clojure as a first programming language?

2016-12-01 Thread Nur Azhar 
Hi,

it's almost 8 years later and I am going to ask these same question since 
it wasn't really answered

Thanks for taking the time to read. I’m interested in trying out Clojure 
> for my first programming language--at least, the first programming language 
> in which I intend to commit myself to becoming proficient.
>
> http://stackoverflow.com/questions/10509283/clojure-as-a-first-programming-language
>
I hope someone replies

On Tuesday, December 1, 2009 at 1:38:58 PM UTC+8, Towle wrote:
>
> Hi all, 
>
> Thanks for taking the time to read my post. I'm interested to get some 
> opinions from experienced Clojure programmers on whether the language 
> would be a good first language to learn, or rather to learn in-depth. 
> I have minimal experienced with more common languages like Java, HTML, 
> and C++, but having the personality I do, felt compelled to shop 
> around a bit before choosing a first language to learn seriously on a 
> deep and intuitive level-- perhaps my odd notion of there being a 
> connection between a programmer and the first language s/he 
> understands on that high of a level. So after shopping around 
> thoroughly and picking up bits about on theoretical computer science 
> and the history of programming languages, I decided to pick up a Lisp; 
> I'm intrigued by the greater concept/idea behind the Lisp family of 
> languages. 
>
> After a long while trying to figure out which of the Lisps would be a 
> good first choice, I stumbled across Clojure and immediately thought 
> it a brilliant idea, conceding of course that at my current level of 
> knowledge, I likely have no idea what a brilliant idea in computer 
> programming looks like. Regardless, it still feels brilliant. 
>
> As I see it, among other features of the language, the idea of a Lisp 
> designed to be a capable choice for "real-world" code applications, 
> that is a Lisp which embodies the spirit of that family of languages 
> yet one which resolves many of the "practicality" complaints which 
> stand as hurdles on a Lisp's path to real-world use. For my situation, 
> that of a student who wants both a) to learn a first language I can 
> have a real, intellectual appreciation for and b) to begin the journey 
> to "expertise" in a language it would be practical to code web 
> applications in. 
>
> So, Clojure programmers, am I wrong? Should I pass on Clojure in favor 
> of another langauge? Or learn Common Lisp or Scheme first, then try my 
> hand at Clojure? Am I mistaken for a different reason? Or perhaps 
> there are some criteria I should consider before diving in? 
>
> Thanks in advance, and again for taking the time to read. 
> --Towle 
>

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