Copyright 2022 Jiří Svoboda
Permission is hereby granted, free of charge, to any person obtaining copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Karlík is Karel's little brother. He can't read or write very well yet, but he'd love to learn some structured programming. Karlík's vocabulary is based on pictures, not words, making it accessible to anybody of any age and speaking any language.
Karlík lives in a city built on a square grid. Each tile contains either nothing, a wall, a tag (white, grey or black), and possibly a robot. At any time Karlík is standing on one square, facing one of the cardinal directions (Nort, South, East, West). He's carrying a backpack that holds a potentially infinite supply of white, grey and black tags.
When Karlík was born he only knew how to do four basic actions
- step forward
- turn left
- put down a tag of a specific color
- pick up a tag
Karlík is eager to learn more. Can you help him?
Karlík is still under construction and not functionally complete.
- Proper images for error dialogs
- Icon dialog to provide icon for new procedure
- List of predrawn and existing icons
- Magnified view / drawing canvas
- Palette
- Preview
- Accept button
- Delete procedure
- Animate program execution step by step
- Show procedure / statement currently being executed in program view
- Calling procedure from procedure (call stack)
- Recursion
- Conditional statement
- Loop statement
You need a working GNU toolchain (GCC, Binutils, Make) (Linux or similar OS) and development files for SDL2, the multimedia library.
To build the software simply type:
$ make
To start Karlík, just type:
# ./karlik
Karlík is very simple to understand and control. It does not use any text, only images. It is controlled using a mouse (or other pointing device) with just one button, using just clicks (no drag and drop, no doubleclick), making it suitable for children and beginners.
Karlík automatically saves its state upon exit and restores it upon start. You can exit Karlík any time by pressing Escape or closing its window. When it is started next time, Karlík will continue exactly where it stopped, everything will be preserved.
When you start Karlík up, you will see Karlík standing in his city. On the top of the screen you can see the main toolbar. It allows you to select between two main modes: Vocabulary and Map. (Karlík starts up in Vocabulary mode by default).
Vocabulary mode allows you to give the robot orders, to teach it new commands and examine existing commands. The second toolbar contains the Work, Learn and Examine icons. On the bottom of the screen you can see a number of commands that you can give to the robot and it will execute them.
Map mode allows you to modify the city's map. The second toolbar allows you to select what you would like to place in the square: Wall, White tag, Grey tag, Black tag, Robot or Delete. Then click on the map to place or delete an object. The delete tool deletes all objects on a square. (A square can contain a robot and a tag, but not multiple tags, nor wall and something else).
With the Work icon selected, you can give the robot commands. You do this by clicking on one of the verb icons at the bottom of the screen. If the robot cannot fulfill the command, an error dialog will be popped up containing a graphical representation of the specific error condition. There are three possible errors: (1) Robot hit a wall, (2) Robot tried to put down a tag on an already occupied square, (3) Robot tried to pick up a tag from an empty square. Clicking the error dialog will dismiss it.
With the Learn icon selected, you can teach the robot a new command. Any new command consists of one or more pre-existing commands. You can append a new command by clicking one of the verb icons at the bottom of the screen. The robot does not executed the command, it just remembers it. The commands being entered are displayed on the right-hand side of the screen.
Once done, click the Bell verb to finish entering the commands.
With the Examine icon selected, you can examine existing complex commands. To examine a command, click on the corresponding verb icon at the bottom of the screen. The details of the command are now displayed on the right-hand side of the screen.
I'd like to thank Richard E. Pattis for creating our beloved friend Karel the Robot.
I'd like to give a nod to the best book on programming ever written anywhere in the multiverse
- Markéta Synovcová: Martina si hraje spočítačem, 107 programů pro robota Karla, 1989 (Martina plays with the computer, 107 programs for Karel the Robot)
To check ccstyle type
$ make ccheck
This requires the ccheck tool from the Sycek project. Ccheck should
not report any warnings.
To run Clang analyzer type:
$ make clean && scan-build make
The analyzer should produce no warnings or errors.