Citrine (programming language): Difference between revisions

Revision as of 22:37, 1 February 2016

Revision as of 07:18, 3 February 2016

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| name = Citrine

| logo = Citrine programming language logo.png

| paradigm = [[object Object-oriented|object programming|Object-oriented]], [[Prototype-based programming|prototype-based]]

| year = 2014

| designer = Gabor de Mooij

| developer = Gabor de Mooij

| latest release version = 0.2

| latest release date = {{startStart date and age|mf=yes|2014|df=y}}

| typing = [[dynamic typing|dynamic]]

| implementations = C

| influenced by = [[Smalltalk]] [[Self (programming language)|Self]]

| influenced =

| operating system = [[UNIXUnix]]

| license = [[BSD licenses|BSD]]

| website = http://{{URL|citrine-lang.org}}

| file ext = ctr

}}

'''Citrine''' is a general purpose [[programming language]] for UNIX[[Unix-like]] operating systems. The languageIt focuses on readability and maintainability.

Readability is achieved by syntacticalsyntactic and conceptual minimalism. The Citrine programming language is heavily inspired by [[Smalltalk]] and [[Self (programming language)|Self]] but has some very distinctive

features. Like Smalltalk, the Citrine language treats everything as an object and focuses on sending messages to these objects. However unlike Smalltalk, Citrine lacks the concept

of a class. In this regard, Citrine is more like [[Self]] and [[JavascriptJavaScript]] because it uses [[Prototype-based programming|prototypes]]. The combination of Smalltalk like messages and prototypes is what makes Citrine unique.

Citrine unique.

== Syntax ==

Citrine has a very limited syntax and it's very closely related to Smalltalk. Everything in Citrine is an '''Object'object'', there are 5 literals:

<source lang="citrine">

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</source>

The code block literal uses a '''pipe''' symbol to separate the parameters from the logic '|', if there are no

parameters, the backslash should be used instead '\'.

Citrine only supports full line comments, comments start with a '#'.

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</source>

This is called a '''unary''' message becausbecause it doestakes not take anyno arguments. A '''binary''' message is always a single UTF-8 character; (this is differentdiffers

from Smalltalk, where there is a fixfixed set of binary messages),. hereHere is an example:

<source lang="citrine">

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Here a binary message '+' is send to number 6, the argument of this binary message is '7', this will result in a new number object '13'.

To assignAssigning the outcome of this operation to a variable one uses the assignment operator: :=.

<source lang="citrine">

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</source>

Also note that each line in a Citrine program ends with a dot, just like in Smalltalk. Besides unary and binary messages, Citrine

also offers '''keyword messages''', these messageswhich take arguments interspersed with the message itself just like Smalltalk and [[Objective-C]].

<source lang="citrine">

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</source>

The code snippet above will return a boolean object '''True'''.

== Control Flowflow ==

Just like Smalltalk, control flow in Citrine is implemented by strategic use of messages. For instance, to writewriting a conditional statement, one has torequires sendsending a block of code

to a boolean.

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</source>

To break out of a loop in Citrine one has to send the message 'break' to a boolean, this allows a conditional break from a loop without having to factor out the break conditions:

without having to factor out the break conditions:

<source lang="citrine">

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Unlike Smalltalk, Citrine has no semi-colon to send a message to the original receiver. Instead Citrine has a comma token ',' used

to chain keyword messages, this allows developerswriting to write UNIXUnix-like '''[[Pipeline (Unix)|pipelines']]''. The following code uses a pipeline-like syntax

to replace all the 'o' characters with zeroes, the resulting string would be something like: '1010101...'.

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</source>

OneThis object can makebe thismade objectto respond to messages by ordering the object to listen to events,. thisThis is kind of similar to

adding methods in languages like [[Java (programming language)|Java]]:

<source lang="citrine">

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</source>

As hasstated been mentioned in this articleabove, inheritance is based on prototypes.

To derive an object from another object, onethe hasnew tomessage sendmust thebe new messagesent to the object

to be extended:

one wishes to extend:

<source lang="citrine">

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== Unicode ==

Citrine uses '''UTF-8''' unicode extensively, both objects and messages can consist

of unicode symbols. All string length are calculated using UTF-8. Citrine distinguishes

string length and size in bytes:

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Citrine uses [[dynamic scoping]] instead of [[lexical scoping]], this means there is no need

for [[Dependencydependency Injection]] or global variables, but it might be harder to reason about than

lexical scope. This is similar as in programming language like

[[EMACS Lisp]] and [[BASIC]]. In code blocks the '''var''' keyword needs to be used to declare

a local variable.

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==See also==

* [[Smalltalk (programming language)|Smalltalk]] - Smalltalk programming language

==References==

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==External links==

* [http://{{Official website|citrine-lang.org Citrine homepage], Citrine homepage}}

* [https://github.com/gabordemooij/citrine source code], Source code on github