A package that is a port of SwissEducs Kara (Page in German). Kara is a concept for an easy access into the world of programming. Kara is a tiny ladybug living in a forest with mushrooms, trees and leafs. Kara can move a single mushroom, place and remove leafs, cannot move trees and is entirely controlled using julia code. In comparison to the original Kara the interaction manly focuses on using the REPL.
Install within Julia in the Pkg REPL-mode using
or in Julia 0.6 in REPL-mode using
Start using JuliaKara by opening Julia and entering
using JuliaKara into the REPL.
Next create a new world of size 10x10 with function bindings in global scope by entering
You can now use
move(kara)to make a step into the direction Kara is facing,
turnLeft(kara)to turn Kara left,
turnRight(kara)to turn Kara right,
putLeaf(kara)to place a leaf beneath Kara and
removeLeaf(kara)to remove a leaf from beneath Kara
treeFront(kara)to check if Kara stands in front of a tree,
treeLeft(kara)to check if there is a tree left of Kara,
treeRight(kara)to check if there is a tree right of Kara,
onLeaf(kara)to check if there is a leaf beneath Kara and
mushroomFront(kara)to check if Kara stands in front of a mushroom.
Alternative methods of creating/loading a world
JuliaKara is aware of the xml syntax the original Kara uses for storing worlds in files.
It's possible to load a world through the GUI or with the command
In contrast to the GUI version
@World [path] opens a new window and registers
kara in global scope as references.
@World "file1.world" move(kara) # moves Kara in world from file1.world @World "file2.world" # kara and world referencing elements from file1.world # are now overwritten with references to elements from file2.world move(kara) # moves Kara in world from file2.world # Create additional references to world and kara world_save = world kara_save = kara @World "file3.world" # kara and world referencing elements from file2.world # are now overwritten with references to elements from file3.world move(kara) # moves Kara in world from file3.world # Access stored references move(world_save,kara_save) # moves Kara in world from file2.world
In case one loads a world through the GUI and wants the above behaviour, the reference to Kara must be restored by:
kara = get_kara(world)
JuliaKara supports multiple worlds and multiple Karas. In case you want to reproduce the example run it from within the test directory of JuliaKara e.g
# Load the world contained in example.world. # This also creates a macro @w1 in global scope to interact with # the world @World w1 "example.world" # Create an empty world w2 @World w2 (10,2) # Place kara in the empty world. # place_kara() returns a reference to the placed kara. # @w2 place_kara(1,1) is just syntactic sugar for place_kara(w2,1,1) kara = @w2 place_kara(1,1) # Kara is already placed in world w1, therefore we fetch it with get_kara() # Since we can't create two kara references we use lara instead. lara = @w1 get_kara() # Move lara a step in world w1 @w1 move(lara) # Alternatively: move(w1,lara) # Move kara a step in world w2 @w2 move(kara) # It's even possible to allow kara from world w2 to # place something in world w1 @w1 putLeaf(kara)
Other useful methods
worldto the state after loading or the last call to
store!(world): Stores the current state of
place_kara(world,X,Y,orientation): Places Kara in
orientation. Valid orientations are
orientationis optional and defaults to
place_mushroom(world,X,Y): Places a mushroom in
place_tree(world,X,Y): Places a tree in
place_leaf(world,X,Y): Places a leaf in
The above used macro for interaction e.g.
@w1 basically translate
@w1 f(args...) to
Thus as all the above methods have
world as their first argument they can also be called using the world macro.
This also works for custom methods:
function turnAround(wo,ka) turnLeft(wo,ka) turnLeft(wo,ka) end @w1 turnAround(lara)
The examples page for JuliaKara contains further material showing the usage of JuliaKara.