{"id":2516,"date":"2021-09-04T18:33:50","date_gmt":"2021-09-04T13:03:50","guid":{"rendered":"https:\/\/www.rangakrish.com\/?p=2516"},"modified":"2021-09-04T18:33:50","modified_gmt":"2021-09-04T13:03:50","slug":"ring-language-dynamic-behavior-of-classes-and-objects","status":"publish","type":"post","link":"https:\/\/www.rangakrish.com\/index.php\/2021\/09\/04\/ring-language-dynamic-behavior-of-classes-and-objects\/","title":{"rendered":"Ring Language: Dynamic Behavior of Classes and Objects"},"content":{"rendered":"

We have been exploring the Ring Programming Language<\/strong><\/em><\/a>\u00a0in the last two articles.<\/strong><\/em><\/a>\u00a0Ring<\/strong><\/em> is a dynamic programming language with many interesting features. In today’s article, let us try to understand how this dynamic behavior is reflected in Classes<\/strong><\/em> and Objects<\/strong><\/em>.<\/p>\n

In Ring<\/strong><\/em>, we can define classes at runtime<\/em><\/strong>. One way to do this is to execute a “script”<\/strong><\/em>. As part of the script, we can define a class, and so when the script is executed, the class gets “defined”<\/strong><\/em>.\u00a0<\/span><\/p>\n

Look at the code fragment below:<\/p>\n

\"Dynamic<\/a>
Dynamic Class Creation<\/strong><\/figcaption><\/figure>\n

When we execute this code, this is the output:<\/p>\n

\"Output\"<\/a>
Output<\/strong><\/figcaption><\/figure>\n

Being able to define classes at runtime is definitely interesting. What happens if we redefine<\/strong><\/em> this class, say, with a different structure?<\/p>\n

\"Class<\/a>
Class Redefinition<\/strong><\/figcaption><\/figure>\n

That is not allowed! This results in an error at runtime:<\/p>\n

\"Redefinition<\/a>
Redefinition Not Allowed<\/strong><\/figcaption><\/figure>\n

Next, let us dynamically define another class that has a single method, and then invoke that method:<\/p>\n

\"Another<\/a>
Another Class Dynamically Created<\/strong><\/figcaption><\/figure>\n

Here is the output:<\/p>\n

\"Invoking<\/a>
Invoking Method Dynamically<\/strong><\/figcaption><\/figure>\n

What if we try to invoke a method that is not defined in the class?<\/p>\n

\"Invoking<\/a>
Invoking an Undefined Method<\/strong><\/figcaption><\/figure>\n

Here is the runtime error:<\/p>\n

\"Undefined<\/a>
Undefined Method Error<\/strong><\/figcaption><\/figure>\n

This is along expected lines.<\/p>\n

Reflection\u00a0<\/span><\/h3>\n

Ring<\/strong><\/em> has an interesting “Reflection”<\/strong><\/em> API. I am going to touch upon just three functions today. For more information, you can go through this article<\/strong><\/em><\/a>.<\/p>\n

The first function we will consider is “methods()”<\/strong><\/em>. Given an object as argument, this function returns a list of methods supported by the object. We can then invoke the “discovered”<\/strong><\/em> methods.<\/p>\n

\"Discovering<\/a>
Discovering Methods at Runtime<\/strong><\/figcaption><\/figure>\n

This is the output:<\/p>\n

\"Invoking<\/a>
Invoking the Discovered Method<\/strong><\/figcaption><\/figure>\n

No surprise here.<\/p>\n

Next, using the “addmethod()”<\/strong><\/em> function, we can add a new method to an object. Likewise, there is an “addattribute()”<\/strong><\/em> function to add an attribute to an object:<\/p>\n

\"Reflection<\/a>
Reflection API Example<\/strong><\/figcaption><\/figure>\n

And the output is:<\/p>\n

\"The<\/a>
The Output<\/strong><\/figcaption><\/figure>\n

What is peculiar and important to keep in mind is that\u00a0 <\/span>we are not<\/strong><\/em><\/span>\u00a0adding the method and attribute to the “DynamicClass2”<\/strong><\/em> class, but only to a single instance of that class. This implies that if we create another object of this class and try to access the method or attribute that we just now added to the other object, we will get an error!<\/p>\n

Here is a code fragment that shows this:<\/p>\n

\"Changes<\/a>
Changes are Object-Specific<\/strong><\/em><\/figcaption><\/figure>\n

Here is the corresponding output:<\/p>\n

\"This<\/a>
Error When Accessing Attribute<\/strong><\/figcaption><\/figure>\n

It is clear that Ring<\/strong><\/em> differs from other popular languages in the way Classes<\/strong><\/em> and Objects<\/strong><\/em> are handled.\u00a0<\/span><\/p>\n

We will continue to explore other features of Ring<\/strong><\/em> in future articles. Here is the code<\/strong><\/em><\/a>\u00a0used in today’s article.<\/p>\n

Have a nice weekend!<\/p>\n","protected":false},"excerpt":{"rendered":"

We have been exploring the Ring Programming Language\u00a0in the last two articles.\u00a0Ring is a dynamic programming language with many interesting features. In today’s article, let us try to understand how this dynamic behavior is reflected in Classes and Objects. In Ring, we can define classes at runtime. One way to do this is to execute […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"advanced_seo_description":"","jetpack_seo_html_title":"","jetpack_seo_noindex":false,"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[17,289],"tags":[292,291,288],"class_list":["post-2516","post","type-post","status-publish","format-standard","hentry","category-programming","category-ring-language","tag-object-orientation","tag-reflection-api","tag-ring-programming-language"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p9OLnF-EA","jetpack-related-posts":[{"id":2496,"url":"https:\/\/www.rangakrish.com\/index.php\/2021\/08\/07\/first-encounter-with-the-ring-programming-language\/","url_meta":{"origin":2516,"position":0},"title":"First Encounter with the Ring Programming Language","author":"admin","date":"August 7, 2021","format":false,"excerpt":"The Ring Programming Language, designed by Mahmoud Fayed,\u00a0 has been around since 2016. I came to know of it quite accidentally two weeks ago when I received a promotional email from Apress about their book \"Beginning Ring Programming\" by Mansour Ayouni, published in 2020. I immediately did a google search\u2026","rel":"","context":"In "C++"","block_context":{"text":"C++","link":"https:\/\/www.rangakrish.com\/index.php\/category\/c\/"},"img":{"alt_text":"Ring Installation Directory","src":"https:\/\/i0.wp.com\/www.rangakrish.com\/wp-content\/uploads\/2021\/08\/directory-300x155.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":3350,"url":"https:\/\/www.rangakrish.com\/index.php\/2024\/03\/09\/the-hy-programming-language-part-2\/","url_meta":{"origin":2516,"position":1},"title":"The Hy Programming Language – Part 2","author":"admin","date":"March 9, 2024","format":false,"excerpt":"I wrote about \u201cHy\u201d language in an earlier article. 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Today's article takes a look at the \"Loop\" command. This command is very similar to \"continue\" in many languages such as C++, Java, Python. etc. It is used to skip the\u2026","rel":"","context":"In "Programming"","block_context":{"text":"Programming","link":"https:\/\/www.rangakrish.com\/index.php\/category\/programming\/"},"img":{"alt_text":"\"Continue\" in Java","src":"https:\/\/i0.wp.com\/www.rangakrish.com\/wp-content\/uploads\/2021\/08\/javacode-300x183.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":3153,"url":"https:\/\/www.rangakrish.com\/index.php\/2023\/07\/02\/the-sum-type-in-v-programming-language\/","url_meta":{"origin":2516,"position":3},"title":"The Sum Type in V Programming Language","author":"admin","date":"July 2, 2023","format":false,"excerpt":"A Sum data type in V language gives us a convenient way to hold objects of many distinct types (at any time, just one object) and hence is a discriminated union. 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