todo: add world with opening/closing fence

todo: create menu collection with these

todo: add image for each of these

Below is a list of example worlds with an ultra-brief summary of what they illustrate, together with the command you need to execute to load the world, so that you can simply copy, paste into the editor (or the REPL) and run the program. In all cases, after loading the world, you should click on World Info to see more details.

Note: if you copy the code World(...) in the Python or Javascript editor and run it, only the content of the Onload editor will be excuted when (re)loading the world. To see the effect of any code in the Pre editor, you will then need to click on the "run" button.

By contrast, if you copy the code World(...) as a line in the Python REPL, both the content of the Onload editor and that of the Pre editor will be executed. The reason for this is that there would be otherwise no reasonable way for you to execute the content of the Pre editor.

add_remove_is_get.json

This world shows how to add and remove different type of "things", and use assert statements to show what the output from
is_X and get_Y would be, for various values of X and Y.

World("worlds/examples/add_remove_is_get.json", "Artefacts")

You might want to add a pause() instruction in the editor prior to running the code, so that you can see more clearly what happens, or simply step through the program while reading the code in the World Info window.

animated_all.json

This world shows the 5 different ways one can animate an image (background tile, object, etc., but not robots). This example is written using Javascript, but can easily be reproduced in Python.

World("worlds/examples/animated_all.json", "Animated")

colors.json

This world shows the different syntax that can be used to indicate a color (name, rgb, rgba, hsl, hsla, #-notation). It also illustrates the use of simpler commands like paint_square() and color_here() which could be useful in end-user's programs.

World("worlds/examples/colors.json", "Colors")

protection_bridge.json, protection_objects.json and protection_example.json

Bridges can protect from otherwise fatal background tiles. Similarly, objects carried can sometimes protect against fatal background tiles and fatal obstacles: this is illustrated in the following two worlds.

World("worlds/examples/protection_bridge.json", "Protection: bridge")

World("worlds/examples/protection_objects.json", "Protection: objects")

For the second example, make sure to read the code in the World Info so that you can add some appropriate code in the editor to see the result.

Finally, for perhaps a more realistic example, have a look at

World("worlds/examples/protection_example.json", "Protection: example").

This last world was saved with some code in the editor which is shown in the World Info by writing INSERT_EDITOR in the description editor.

simple_path.json, simple_path_explained.json and simple_path_grid.json

simple_path.json shows a world that could be given to a student as a simple programming task; the content of World Info is limited to what is needed by the student.

By contrast, the content of World Info simple_path_explained.json includes the code explaining

1. how move is redefined to keep track of the path followed,
2. how done is redefined to prevent the user from ending a program before the code in the Post editor is run and
3. how a custom test is added in the Post editor to verify that the desired path has been followed.

World("worlds/examples/simple_path.json", "Simple path")

World("worlds/examples/simple_path_explained.json", "Simple path explained")

Finally, beginners may find it difficult not to see the grid which is hidden by the background tiles. We can change a settings to show the grid as illustrated in simple_path_grid.json.

World("worlds/examples/simple_path_grid.json", "Simple path with grid")

boring_path.json and nice_path.json

boring_path.json shows a basic world with the "look and feel" of a traditional "Karel the robot" presentation. nice_path.json shows a world that is functionally identical, but that looks very different.

World("worlds/examples/boring_path.json", "Boring path")

World("worlds/examples/nice_path.json", "Nice path")

Like was done for simple_path_grid.json, with nice_path.jsonone could set RUR.state.visible_grid to True to show the grid.

river.json and river_demo.json

These two worlds show how one can create a seemingly unpassable river by using water as a decorative object instead of a background tile. The first one shows how I would present this task to students (but without showing them the code included in the description).

World("worlds/examples/river_demo.json", "Crossing the river")

In the second version, I do not draw the safe river passage in the Onload editor, but do so in the Pre editor instead. This way, one can see before running the program where the passage will be.

World("worlds/examples/river.json", "River")