Clojure is a general-purpose language supporting interactive development that encourages a functional programming style, and simplifies multithreaded programming.

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7answers
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C# Dev - I've tried Lisps, but I don't get it

After a few months of learning about and playing with Lisp, both CL and a bit of Clojure, I'm still not seeing a compelling reason to write anything in it instead of C#. I would really like some ...
33
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4answers
3k views

What did Rich Hickey mean when he said, “All that specificity [of interfaces/classes/types] kills your reuse!”

In Rich Hickey's thought-provoking goto conference keynote "The Value of Values" at 29 minutes he's talking about the overhead of a language like Java and makes a statement like, "All those interfaces ...
33
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6answers
2k views

Why is “tight coupling between functions and data” bad?

I found this quote in "The Joy of Clojure" on p. 32, but someone said the same thing to me over dinner last week and I've heard it other places as well: [A] downside to object-oriented programming ...
31
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13answers
2k views

Problems (such as maintenance) in development with unpopular language

I'm developing some application with clojure(lisp) alone in my team. It starts as small application. No problem. But as it's having features and extending the area, it's becoming important program. I ...
25
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4answers
4k views

What limitations does the JVM impose on tail-call optimization

Clojure does not perform tail call optimization on its own: when you have a tail recursive function and you want to have it optimized, you have to use the special form recur. Similarly, if you have ...
22
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3answers
1k views

Why do some functional languages need software transactional memory?

Functional languages, by definition, should not maintain state variables. Why, then, do Haskell, Clojure, and others provide software transactional memory (STM) implementations? Is there a conflict ...
19
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2answers
3k views

Is Clojure, Scala and other restrained by the JVM vs CLR [closed]

The Java implementors seem slow to adopt language improvements, for example compare C# with full closures, expression trees, LINQ etc.. to Java, and even the push back of some stuff to Java 8 will ...
18
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6answers
3k views

Advantage of Learning Lisp for a Python Programmer

I am primarily a Python, Java, C++ programmer, and I've gained a recent interest in functional language. I'm thinking of picking up a LISP dialect: Clojure. Now, I've been working through tutorials ...
17
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3answers
2k views

Why does the Lisp community prefer to accumulate all the parentheses at the end of the function?

Why does the Lisp community prefer to accumulate all the parentheses at the end of the function: (defn defer-expensive [cheap expensive] (if-let [good-enough (force cheap)] good-enough ...
15
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1answer
3k views

Is shipping a Clojure desktop app realistic?

I'm currently shipping a desktop Java application. It is a plain old Java 5 Java / Swing app and so far everything worked nicely. Java 5 was targetted because some users were on OS X version / ...
14
votes
6answers
3k views

Best practices in comment writing and documentation

Commenting nowadays is easier than ever. In Java, there are some nice techniques for linking comments to classes, and Java IDEs are good at making comment shells for you. Languages like Clojure even ...
14
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3answers
11k views

What's so great about Clojure? [closed]

I've been taking a look at Clojure lately and I stumbled upon this post on Stackoverflow that indicates some projects following best practices, and overall good Clojure code. I wanted to get my head ...
14
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3answers
6k views

On the path to Enlightenment: Scheme, Common Lisp, Clojure? [closed]

A lot of people smarter than me keep writing about when you learn Lisp it makes you a better programmer because you "get it". Maybe all I hear about Lisp(s) changing your life is just a big practical ...
13
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3answers
1k views

How independent is Clojure from Java?

I am quite new to the Clojure world. I appreciate the fact that one has easy access to all Java libraries via Clojure interop features, but I was wondering how much Clojure stands on its own legs. Of ...
12
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5answers
2k views

In what programming language did “let” first appear?

I was wondering about the origins of the "let" used in Lisp, Clojure, and Haskell. Does anyone know which language it appeared in first?
12
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1answer
1k views

Does Clojure have the continuation?

I started programming with Python. When using python, concepts like coroutine, closure made me really confusing. Now I think I know them some superficial level, but I want to get the "enlightement" ...
11
votes
2answers
1k views

How will the new development of Java influence its interoperability with languages like Scala and Clojure?

As far as I understand, both Scala and Clojure have been designed as new languages that depend on the JVM, and easily integrate with Java code, in the sense that they allow to use Java classes ...
11
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3answers
1k views

Scala or Clojure Functional Programming best practices

I did a lot of self-study coding, got some experience with Parallel Programming Models: Actors, Software Transactional Memory, Data Flow. When I am trying to apply these architectures to real life - ...
10
votes
3answers
580 views

Byte code weaving vs Lisp macros

I have been reading about the libraries people have written for languages like Java and C# that make use of byte code weaving to do things like intercept function calls, insert logging code, etc. I ...
10
votes
3answers
2k views

How dependent on Rich Hickey is Clojure? [closed]

I was just asked this question by my company who is investing in a Clojure application and I did not have a good answer? Can anyone, in all seriousness tell me what would happen to Clojure if Rich ...
9
votes
4answers
770 views

Python decorators and Lisp macros

When looking Python decorators someone made the statement, that they are as powerful as Lisp macros (particularly Clojure). Looking at the examples given in PEP 318 it looks to me as if they are just ...
9
votes
3answers
396 views

Making LISPs manageable

I am trying to learn Clojure, which seems a good candidate for a successful LISP. I have no problem with the concepts, but now I would like to start actually doing something. Here it comes my ...
9
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1answer
309 views

Software Transactional Memory - Composability Example

One of the major advantages of software transactional memory that always gets mentioned is composability and modularity. Different fragments can be combined to produce larger components. In ...
8
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9answers
2k views

OS choice for functional developing

I'm mainly a .NET developer so I normaly use Windows/VisualStudio (that means: I'm spoiled) but I'm enjoying Haskell and other (mostly functional) languagues in my spare time. Now for Haskell the ...
8
votes
1answer
1k views

How to write readable Clojure Code?

I am new to Clojure. I can understand the code I write but it becomes too difficult to understand it later. It becomes difficult to match parentheses. What's the generic conventions to follow ...
8
votes
3answers
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Why can't we write nested shorthand functions in Clojure?

I tried to evaluate a Clojure expression with nested shorthand functions today, and it wouldn't let me. The expression was: (#(+ % (#(+ % (* % %)) %)) 5) ; sorry for the eye bleed The output was: ...
8
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1answer
231 views

Accessing the history of a `ref` in Clojure

The documentation for ref shows a :max-history option and states that "refs accumulate history dynamically as needed to deal with read demands." I can see that there is history at the REPL, but I ...
8
votes
1answer
723 views

What are the essential Clojure libraries to learn beyond the basics of “core”

I am teaching myself Clojure. I've started using Leiningen, I'm working on Clojure Koans, plan to do LabREPL next, and will have a look at Noir. My question is: what are the essential "must know" ...
8
votes
2answers
399 views

Where do we put “asking the world” code when we separate computation from side effects?

According to Command-Query Separation principle, as well as Thinking in Data and DDD with Clojure presentations one should separate side effects (modifying the world) from computations and decisions, ...
7
votes
2answers
1k views

Could we build a functional computer?

As mush as FP has done, in the end, all our programs are structured. That is, it doesn't matter how pure or functional we make a them - they are always translated to assembly, so what actually runs ...
7
votes
2answers
850 views

Are square brackets and curly braces in Clojure still S-expressions?

I am trying to learn Lisp and looking at all the Lisps out there and their differences. I see that in some implementations of Scheme, you can use square brackets interchangeably with round brackets ...
7
votes
2answers
423 views

When would I require a Macro instead of a function?

I am new to Clojure, I am new to Macros and I have no prior background in Lisp. I went on to create my own switch case like form and ended up with this: (defmacro switch-case [v cases default] (if ...
6
votes
5answers
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Is Clojure's syntax really simpler than Scala's? [closed]

Argument which is always made in favour of Clojure is that. The syntax is simpler and there is only one way of expressing code with no complicated rules. However Scala has loads of different types ...
6
votes
2answers
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Is Haskell/Clojure actually unsuited for dynamic systems such as particle simulation?

I've been told in previous questions that functional programming languages are unsuited for dynamic systems such as a physics engine, mainly because it's costly to mutate objects. How realistic is ...
6
votes
2answers
584 views

What is a dotted pair's analogy in other Lisp implementations?

What is Scheme's dotted pair construct analogous to in other Lisp implementations? I can make a vector or list quite easily, and understand those in Clojure, even though the syntax is a little ...
6
votes
2answers
634 views

How do people get rid of conditional branches in Functional Programming?

Long running switch cases or if-else-if constructs are avoided in OOP using polymorphism wherever it is applicable. instead of branching by matching a value, branching is done at class-level itself. ...
6
votes
5answers
2k views

Clojure Web Application: EC2 or GAE?

I am developing a web application written in Clojure using the Compojure framework. My question is, should I deploy to Amazon EC2 or Google App Engine? I've read this article on running Clojure code ...
6
votes
1answer
686 views

Pattern matching in Clojure vs Scala

What are the key differences between pattern matching in these two languages? I am not referring to syntax, but capability, implementation details, range of use cases and necessity. Scala ...
6
votes
1answer
212 views

Is it fair to say that “macros don't compose”?

On this blog post aphyr (who is a brilliant programmer) states: Clojure macros come with some important restrictions. Because they’re expanded prior to evaluation, macros are invisible to ...
6
votes
2answers
227 views

Language that can statically ensure a map's fields are present

If data is simple and objects are complex, I'm curious if there are any existing statically typed languages that would be able to augment(?) a map type into a type with guaranteed fields. I realize ...
5
votes
1answer
510 views

How to refactor a Java singleton to Clojure?

I'm writing a simple game in Java and I want to learn Clojure, so I've decided to refactor my current Java code to Clojure. The problem is that I've coded so much in object-oriented languages that I ...
5
votes
2answers
218 views

Can the Clojure set and maps syntax be added to other Lisp dialects?

In addition to create list using parentheses, Clojure allows to create vectors using [ ], maps using { } and sets using #{ }. Lisp is always said to be a very extensible language in which you can ...
5
votes
2answers
938 views

Can Clojure's thread-based agents handle c10k performance?

I'm writing a c10k-style service and am trying to evaluate Clojure's performance. Can Clojure agents handle this scale of concurrency with its thread-based agents? Other high performance systems ...
5
votes
1answer
345 views

Setting up Clojure Project And Sub Projects

This is primarily a lein question about setting up a major project and its sub-projects, and is not intended to be a discussion question. Instead, I am interested in either a pointer to documentation ...
4
votes
2answers
208 views

Evaluation order of expressions in Clojure?

I'm currently learning Clojure (my first functional programming language), and I'm curious as to its order of evaluation. Here is an example: (take 10 (cycle [1 2 3])) If the cycle expression was ...
4
votes
4answers
3k views

Using Clojure instead of Python for scalability (multi core) reasons, good idea?

After reading http://clojure.org/rationale and other performance comparisons between Clojure and many languages, I started to think that apart from ease of use, I shouldn't be coding in Python ...
4
votes
1answer
1k views

Clojure: vars, atoms, and refs (oh my)

also: defs, java fields, agents The clojure website has documentation for these concepts: Vars Atoms Refs Agents I understand the words, but I don't conceptually get the purpose / meaning of ...
4
votes
2answers
226 views

Determinism of functions using PRNG in Clojure and functional languages

I'm a bit surprised by a sentence found in the book "Clojure Programming" (1st [and only as I write this!?] edition), page 78: It should be obvious that it's impossible to deterministically test a ...
4
votes
1answer
329 views

Is re-defing idiomatic in clojure?

Simple example: (def ticks 0) (defn run-iteration [] (def ticks (inc ticks))) Though the usual case involves things that don't change more than once every several hundred ms. How to do this ...
4
votes
2answers
606 views

Alternate method to dependent, nested if statements to check multiple states

Is there an easier way to process multiple true/false states than using nested if statements? I think there is, and it would be to create a sequence of states, and then use a function like when to ...