Getting Started with Clojure in .net

Admin — Wed, 04 Nov 2009 08:00:00 GMT

Before getting started here is the pre-requisites for installing ClojureCLR

Microsoft .NET Framework Version 3.5 SP1
Visual Studio 2008 SP1
Dynamic Language Runtime
NUnit
RhinoMocks

These are the steps followed by me for the new installation

Created a folder called ClojureCLR
Downloaded the Dynamic Language Runtime and extracted the DLR_Main folder into the above folder
Compiled the DLR by opening the visual studio solution file inside DLR_Main
Downloaded the ClojureCLR by using the git (Windows version can be downloaded here) and Opened the ClojureCLR.sln file
Added references for NUnit and Rhinomocks (with castle dependencies download from here) Clojure.Tests project
Set Clojure.Main as startup project and then Crl + F5 or F5 will start the interactive Clojure section

Clojure is dynamic i.e,

Clojure can be embedded in .net applications and can be interacted with
Can be used as a scripting language inside .net
Can be interacted with the primary programming interface called Read-Eval-Print (REPL) loop
Supports dynamic compilation

Part of clojure called Reader will read the clojure program in chunks called forms and translates them in to clojure data structures. when run for the first time, the clojure REPL will display the following prompt.


Clojure 1.1.0-alpha-SNAPSHOT
user=>

Prompt displays the default namespace and is ready to evaluate the clojure programs. Let's feed it with a number.


Clojure 1.1.0-alpha-SNAPSHOT
user=> 42 1
42

user=> (+ 2 3)2
5

Number literal 1 is a Form in clojure and evaluates to itself. Let's feed the REPL with a function that calculates the sum of two numbers 2. Several deviations from the imperative programming languages are evident from this single expression.

All program codes are written in parenthesized lists
A function call is written as a list with the function or operator's name (+ in the above code) first, and the arguments following (2 and 3 in above code)
White space is the commas in Clojure (2 3 in the above code as arguments instead of 2, 3)


Clojure 1.1.0-alpha-SNAPSHOT
user=> (+ 4 6) 3
10
user=> (- 5 4) 4
1
user=> (/ 2.0 3) 5
0.666666666666667
user=> (* 5 6) 6
30
user=> (inc 4) 7
5
user=> (dec 4) 8
3
user=> (quot 12 5) 9
2
user=> (rem 12 5) 10
2
user=> (min 2 3 4 1) 11
1
user=> (max 2 3 4 1) 12
4

Add, Subtract, Multiply, Divide, Increment, Decrement, quot[ient] of dividing numerator by denominator, remainder of dividing numerator by denominator, least of the nums and the greatest of the nums are the computations supported by the clojure on Numbers. In addition to the bitwise operations the numbers support the following comparison operations.


Clojure 1.1.0-alpha-SNAPSHOT
user=> (== 1 1)
True
user=> (< 1 2)
True
user=> (<= 3 4)
True
user=> (> 3 2)
True
user=> (>= 4 3)
True
user=> (zero? 4)
False
user=> (pos? -2)
False
user=> (neg? -2)
True

Other data structures will be covered in future posts.

clojureclr - on code

Getting Started with Clojure in .net