3.txt

Goals and Structure
I want to accomplish a couple of things with this code. First and foremost, I want to implement a block language for turtle graphics, with which you can write code to create images through simple dragging-and-dropping of blocks, using as simple a structure of HTML, CSS, and JavaScript as possible. Second, but still important, I want to show how the blocks themselves can serve as a framework for other languages besides our mini turtle language.

To do this, we encapsulate everything that is specific to the turtle language into one file (turtle.js) that we can easily swap with another file. Nothing else should be specific to the turtle language; the rest should just be about handling the blocks (blocks.js and menu.js) or be generally useful web utilities (util.js, drag.js, file.js). That is the goal, although to maintain the small size of the project, some of those utilities are less general-purpose and more specific to their use with the blocks.

One thing that struck me when writing a block language was that the language is its own IDE. You can't just code up blocks in your favourite text editor; the IDE has to be designed and developed in parallel with the block language. This has some pros and cons. On the plus side, everyone will use a consistent environment and there is no room for religious wars about what editor to use. On the downside, it can be a huge distraction from building the block language itself.