Custom Rouge Themes and How to Fix the Ruby Rouge::Theme uninitialized constant problem

After the most recent changes to the Copper programming language and a switch to a newer computer, I decided to finally rebuild the documentation. I have been using the Slate static site generator creating with Ruby on Rails which uses redcarpet and rouge. Sadly, on a new machine, I had to set up everything again. As you may have discovered, rouge, despite its popularity, has really crappy documentation. Ruby itself is crappy in my opinion and I hate working with it, but there has been some nice stuff created with it. Slate is one example. However, after the headache of trying to dig up the documentation, I may switch to using Copper to generate its own documentation. Not a bad idea, no? Anyways, I decided it would be useful to share my tidbits of knowledge with others who will stumble on this problem while creating custom themes for rouge.

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are_available(builtin)

Some time ago, I decided to stop making features for the Copper interpreter engine, but I ran across a situation in coding where I came up with an idea for a very convenient built in function.

Replacing the Body of an Object Function

Suppose you have an object “a” that you have already instantiated members in.

a.b = 10

Now suppose you need to make the return of “a” equal to 9 so that:

print(a:)

… prints “9”. If you were to assign 9 to “a” directly, you would be giving “a” an entirely new object-function, thereby losing the member “b”. Fortunately, there is a way around the problem. Copper has a built-in function called “share_body” that allows two object-functions to share the same execution body. For example:

c = 9
share_body(c a)

… would allow “a” to have the body of “c”. If “c” gets destroyed from going out of scope, then “a” keeps the body. However, creating a new variable just to make a function body is unnecessary. If we create an ownerless object-function to share its body with “a”, then “a” will become the owner of the body.

share_body({9} a)

The ownerless object-function {9} is instantiated within the function-call parentheses of share_body where it dies but its body lives on. And there you have it, no copies required, no loss of object members.

Multidimensional List Solution

In a previous article, I wrote about how it was difficult to produce a 2D list in Copper due to the ownership dilemma. The solution at the time was to write a singly-linked list in Copper. It turns out, there is a better approach, one that will also allow us to create any multi-dimensional list.