Konrad Komorowski - Creating A Scrabble-playing Application

Personal Project  Creating a Scrabble‐playing application  created by:

Konrad Komorowski supervised by:

Anita Pawłowska

02.03.2007 Gdynia Bilingual High School No 3 and International Baccalaureate School No 0704

Table of Contents  Introduction ............................................................................................................................................. 3 Description of Process ............................................................................................................................. 4 Inspiration............................................................................................................................................ 4 Planning ............................................................................................................................................... 4 Choosing the tools ........................................................................................................................... 4 Learning Java .................................................................................................................................. 6 Development of the program ............................................................................................................... 7 General idea..................................................................................................................................... 7 Word list .......................................................................................................................................... 7 Construction of the program............................................................................................................ 7 Future prospects .................................................................................................................................. 9 Licensing the work .......................................................................................................................... 9 Propagating the work..................................................................................................................... 10 Further development...................................................................................................................... 10 Analysis of the inspiration, research and influences guiding the work ................................................. 12 Conclusion ............................................................................................................................................. 13 Bibliography .......................................................................................................................................... 14 Appendices ............................................................................................................................................ 15

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Introduction  The purpose of my Personal Project is to create a Scrabble-playing application,1 i.e. a program with which one would be able to play Scrabble. I decided to choose this subject firstly just because of the fact that it is a demanding goal and I simply like challenges. Secondly, it can still be something of real use, because there are a lot of people who like playing Scrabble and sometimes do not have the opportunity to do so if it is impossible to contact other people with the same interest. Last but not least, designing and algorithm playing a game requires a lot of skills in the area of logic, which is one of my interests. The exact topic however didn’t derive from those three outlined reasons. It was more like an idea that popped into my head quite of its own accord and was accepted because it perfectly fulfilled the requirements I had towards my Personal Project goal. The goal of my Personal Project is to create an application. Usually, this process of creation should be the one guiding my work. Consequently, Man Creator – the Homo Faber Area of Interaction could be considered the one giving shape to my whole project. However, a very important factor is the fact that I do not know yet any computer programming language, which is absolutely indispensable in my work. As a result, my project gains a second task – the learning of programming. Thus, it will not only check my abilities of making a program, but also firstly learning how to do it. Approaches to Learning will be the key factor determining the success or failure of my work. To conduct it smoothly, and simply without any unnecessary problems, I will have to find a reasonable consensus between the creation of the program as such and gaining skills essential in carrying out this task. Should I succeed in it, it could prove a product profitable not only for me, by giving the useful experience, but also for the community, by providing a free, and hopefully convenient, way of playing Scrabble with the computer. The goal of my Personal Project is clearly stated, so are the actions I have to take in order to achieve it. The first thing I will have to do is to work out a general idea of how the program is going to look like and work. Being able to consult original Scrabble manual would be a very useful aid in it. Then I will have to choose a specific programming language in which to program my work. At the beginning of my work I didn’t know any of those, so after choosing one the next step would be mastering its basic usage. Finally, after all the preparation I would have to simply code my program and make it somehow available to wider public, preferably by publishing on the Internet.

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Scrabble – a popular word game and board game in which 2 to 4 players score points by forming words from individual lettered tiles on a 15-by-15 game board. The words are formed across and down in crossword fashion, and must appear in a standard dictionary. From http://en.wikipedia.org/wiki/Scrabble.

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Description of Process  Inspiration  I first came to the idea of producing a Scrabble-playing application on 30 April, 2006. While talking to my parents’ friend I learned about various computer programs that provide an aid in playing Scrabble. The application I was told about showed possible words that fitted a provided regular expression2. I had just finished coding a very simple Java program then – a school assignment. Therefore, I thought about extending the possibilities of such a program by coding an application that would be capable of analysing the whole gameboard and showing the player all the possible moves they can make (of course given the player’s tiles). Then I realised that coding such and application would virtually mean doing the majority of work needed to produce a fully functional Scrabble-playing application. By that time I had been already informed about the need to choose a Personal Project topic. As a result I chose to code a Scrabble-playing application for my Personal Project. I started to think about the engine of the game right away. I came up with quite a lot of ideas, but looking from a wider time perspective, I eventually didn’t use majority of them, if any.

Planning  Choosing the tools  After the primary stage of unordered ideas about the project I had to do some more serious work. Precisely, I decided to choose the programming language and the software in which to code the program. Programming language  Generally speaking computer cannot understand human logic and vice versa. Computer processors operate in bits, which are variables that have the value of either 0 or 1. The CPU3 is capable of operating those values extremely fast. However, despite being able to make billions of calculation per second, the CPU is quite simple. It can be told what to do only using its machine code – a set of particular uncomplicated instructions perfectly understood by it. However, the machine code is not human-readable. Although it can be understood after careful study of the processor’s construction, trying to design complex actions writing them directly in the machine code would be extremely inefficient. Moreover, every type of CPU has a different structure – understands different machine code, so the programs either would have to be written separately for different architectures4 or we would have to restrict ourselves to only one type of CPU. What a terrific loss of opportunities of development and competition in the computer industry it would have been! 2

Like: show me all the accepted words that begin with W, then have any letter, then U, then either L or N and then D – “w.u[ln]d”. The application would return would and wound. 3 Central Processing Unit 4 CPUs types

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That is why more abstract computer languages like Java, Python, C++ or C# have been designed. They are completely incomprehensive for the CPU, but humans, possessing the ability of abstract thinking, can read and write in them. The code produced by humans is then translated by compilers into the machine code, which can be then executed by the CPUs. However, the machine code itself cannot be modified by human beings, as it is simply unintelligible for them. Only by being given the abstract language code of the program other people can edit it, and then compile and run by themselves. This abstract language code of the program is called the source code and the already compiled program – an executable file. Programming languages possess different levels of abstractness. The general rule is that the more abstract a language is (the higher-level language it is), the less efficient it is. The human does not directly design the processor’s actions but let them be automatically transformed into machine code by a non-intelligent compiler. Therefore the less control the programmer has over the basic parts, the fundaments of the program, the more is handled by a non-intelligent compiler, what inevitably leads to a loss of efficiency. Old and traditional low-level languages like C are not as abstract as the newer high-level ones, such as for instance Python. Consequently, low-level languages are more efficient than the high-level ones but require greater knowledge of the construction of a computer and in almost all cases require more coding to design a specific action.5 6 At the time of April the 30th I had already had some lessons on the Java programming language – quite a specific high-level language.7 I had even bought a book on Java, Praktyczny kurs Java8, which I hadn’t read yet then. After a few weeks of consideration I decided to choose Java as my programming language because: 1. It is high-level – programming in it doesn’t require that much knowledge about the work a computer. I decided to sacrifice the efficiency in return for considerably shorter and easier process of learning the language and coding the program.

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So there is a possibility that a poor low-level programmer can still do worse than a wisely designed high-level compiler. 6 This is of course a simplification. Computers’ work is much more complicated than simply writing source code and compiling it for the CPU. Many solutions are adopted in order to increase the efficiency and usability of computer systems, which are far too complicated to discuss in this work. 7 The specificity consists in the fact that it is generally practised that the Java source code is not directly translated into the machine code. Instead, it is translated into beta-code – a halfway stage between humanreadable code and machine code. Additionally, there is such a thing as Java Runtime Environment whose most important part is the Java Virtual Machine. JVM is capable of translating the beta-code into the machine code of the CPU on which it is working. JREs are produced for many operating systems and CPU architectures. As a result, the programmer doesn’t have to compile their code for different architectures – beta-code will work on any operating system, provided that there is a JRE for it. This universality makes Java multi-platform, but also negatively affects its efficiency. 8 pl. Practical Java course, listed in the bibliography

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2. It is multi-platform – I was planning a Windows to Macintosh transition at the time, so choosing Java would make the switch smooth and allow me to code on Macintosh a program that could be easily executed by anyone running the most popular Windows. I had enough knowledge to make this decision because I was already quite interested in the computerrelated topics. Development environment  Source code of a program is just a sequence of characters; usually interpreted by the compiler (other possibilities are for instance a Virtual Machine, as in Java, or an on-the-fly interpreter, as in some script languages like Python). So, theoretically, a program could be written in simple text editors like Mac OS X TextEdit or Windows Notepad. However, writing every line of code on one’s own, without the help of any additional features is tiresome and ineffective. Those features include a quick, oneshortcut compilation of the program to check for errors quickly, smart management of already produced parts of code to be able to easily refer to them later on etc. Programs that have such features, and are usually designed to work with specific programming languages, are called IDEs.9 The IDE that I was told by my computer science teacher to use was free jCreator10 (see Figure 1). I personally didn’t feel comfortable with it. This could have been caused by the fact that I virtually didn’t know how to program in Java. Nevertheless, when I visited a Polish social networking website – Spinacz11, I found out on the Java-related group’s forum that the most praised Java IDE there was Eclipse12 (see Figure 2). It was also a free product, even more – and open source13 project, that was used by many experts. It had a professional and clear look, its functions were intuitive. In simple words, I liked it from the very beginning. Additionally, because the fact that it was open source, Eclipse was ported by many individuals to work on different operating systems. That said I could code with the same program on Windows, Linux, FreeBSD and Mac OS X. Having considered it and found on the Internet many very positive opinions about Eclipse I chose it to be my IDE. Learning Java  I decided that I do not have enough time to learn Java and then start my project. Instead, I took another strategy. I quite carefully read the whole Practical Java course in about a month, which wasn’t a most demanding lecture – only an introduction to Java programming. I also bought two other materials by the same author – Java. Pocket lexicon and Java. Computer science tables. Knowing the very basics of 9

Integrated Development Environment http://www.jcreator.com/ 11 http://www.spinacz.pl/, pl. paper clip (a reference to linking people each other) 12 http://www.eclipse.org/ 13 Open Source Software is software for which the underlying programming code is available to the users so that they may read it, make changes to it, and build new versions of the software incorporating their changes. There are many types of Open Source Software, mainly differing in the licensing term under which (altered) copies of the source code may (or must be) redistributed. http://domainsmagazine.com/managearticle.asp, accessed via Google definitions search. 10

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Java I started coding my Personal Project as in fact the second Java program bigger than 50 lines of source code in my life. At the same time I ordered a very advanced book on Java – Thinking in Java by Bruce Eckel. It is more than 1200 pages long so reading through all of it in the course of my last MYP school year would be virtually impossible. I decided that I would consult the book only if I had any doubts or problems concerning my program.

Development of the program  The next step after the necessary planning and preparation was the Project itself – coding the program. I will not present designing the full engine here, as it far too complicated to present within the volume limit of the work. The whole process is described in the log book.14 General idea  The general idea I tried to follow while coding my program is the following: the application is constantly aware of every single word15 that can be put anywhere in the gameboard, in compliance with the Scrabble rules – from now on called in my work a potential input. Then, when one of the computer players turn comes, the AI16 of the application will run through all of the potential inputs and check which of them can be inserted using the tiles possessed by the AI player on whose behalf the AI is working. Then, it will assess the possible moves according to a given, mostly based on the move’s score, key. In case of a turn by a human player, the application will simply check if a given word exists in its current database, without analysing the move as such. Word list  For my application to be able to check if given words exist in the English language I had to find a dictionary whose license would allow me to use it in my program without the need to pay anyone. Using the Google search I found a webpage about Miscellaneous Shareware and Freeware,17 where some English words lists were presented. I chose the longest available – YAWL 0.3.218, containing about 264,000 American English words. Construction of the program  Possible inputs database  For the database of all the possible inputs to be constantly up-to-date I acquired the strategy of instant updates, i.e. every action affecting the gameboard – inserting new tiles – would make the program recalculate the potential word inputs in specific places of the gameboard. I had to very carefully design the algorithm for chooses places in which to look for potential inputs updates, for the program to cover all the possible updates, but under no circumstances rescan the whole 14

The frequency of entries is falling towards the end of the project due to extensive amount of school work. However, still not longer that the specified tiles per one player number limit. 16 Artificial Intelligence 17 http://personal.riverusers.com/~thegrendel/software.html 18 An abbreviation for Yet Another Word List, unfortunately it doesn’t seem to have any official website. 15

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gameboard, because such an action would lengthen the computers calculations to an unacceptable scale. I managed to write an optimal algorithm for finding such potential updates, whose exemplary work is presented in Figure 3. (The red word is the newly inserted one, green fields are fields at which begin potential new vertical words that need to be updated, blue are analogical but refer to the horizontal potential words and the red fields combine both horizontal and vertical updates. Note that for instance potential 4 letters long vertical words beginning at row 1 and column 7 do not need to be updated. Such improvements are included in my algorithm.) AI’s input choice  As planned, I coded the AI of the game so that it runs through all of the possible words, checks which inputs can be made by a given player and then assesses each of them. I design a special formula to assess the value of a given input: ·

∑

·∑

·

( – the value of an input, – score of the input, – the number of tiles used, tile of the input19,

– value of a given one

– number of occurrences in the dictionary of a given one letter of the input20,

the number of tiles left in the sack,

–

– the total number of tiles in the game)

The idea behind the formula is that score matters the most (risen to the power of 6). Then, the better tiles are used (on average!), the less valuable the input is (the multiply by ∑

·∑

part). However, this

matters less and less, as the game progresses (the fewer tiles are left in the sack the more the multiply by and add

part brings the value of ∑

·∑

to meaningless one).

User’s input validation  As in the plans (however unlike the very first plans), the approval of users’ moves also relies only on the existence of the move in question in the possible inputs database. Program­user interaction  After coding the engine of the game I had to design the system of user’s interaction with the application. I choose not to develop a Graphical User Interface because of one main reason – lack of time. If I had wanted my application to have a GUI I would have had to firstly learn how to do it, then design the interface and code it. This would take definitely too much time. So I decided that my program would be a command line application. Basically, it means that my program would communicate with the user using only text commands. (See Figure 4 for a sample application-user interaction.) I also designed a few commands non-essential in playing Scrabble that can prove useful 19 20

The higher, the more valuable. As above.

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during the game. For a list of all the commands with explanation see Figure 5 – the output of my program’s help command.

Future prospects  Licensing the work    When I had finished the product itself I had to choose an appropriate license for its source code. My primary assumption was that the program would be open source, i.e. I would make the humanreadable Java code freely available along with the end-user specific Java beta-code. As a result, anyone interested in my project would be able to check how every aspect of the application works and, if they wished to, change anything for their needs. I made it possible because I had no intention of selling the software. I considered my work an educational, not commercial project. So, as I didn’t need to protect my programming solutions from the eyes of other people (to control the development of the application and make profit out of it), I decided that in fact I didn’t need to protect my programming solutions anyhow. So I made every bit of the source code open for everyone. In the world dominated by the idea of management of the so called intellectual rights, it is an established custom to make the source code available under a given license. There are hundreds of such licenses, each of them imposing different duties and limitations upon the user of the licensed source code. In the open source community there are two dominating licenses: BSD and GPL. Berkeley Software Distribution License  Generally speaking, this license stresses that the author of the code is not responsible for any problems caused by the software. It doesn’t prohibit redistribution of the modified code without the source code, thus makes it possible to use the code in commercial products. See Figure 6 for the full text of the newest version of the BSD License. GNU Public License  The most significant difference between GPL and BSD is that every program based on a GPL code has to be redistributed under the terms of GPL. The terms hold that the program is distributed with its source code, so consequently GPL code cannot be used in any commercial work. See Figure 7 for the GPL summary. Massachusetts Institute of Technology License  The MIT license is based on the BSD license, but has most of the clauses removed, the whole text simplified and a clearly stated permission for selling and relicensing the software. See Figure 8 for its full text.  

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Final choice  I decided that the MIT License is the most appropriate one. GPL is hypocritical, with its authors claiming that intellectual property doesn’t exist and still imposing on the code users very strict clauses. On the other hand, BSD License is very liberal, what fits my views on the intellectual property. MIT License, as a further simplified BSD License is in my opinion the best license choice for a clear and just software. Propagating the work  To propagate the work I prepared a webpage about it (see Figure 9). I called the program jScrabble21 to be possible for it to be recognised by potential users. I used the Google Page Creator22 to create the layout, Google Apps for Your Domain23 to host it and my domain kundziad.net to make the official WWW address of my page – http://jscrabble.kundziad.net. The page has information on running the software, every version of the program I have produced and some contact information to me – my email and Jabber ID. Further development  My application is in the early stage of its life. Just after being produced, some features are not optimally developed yet, some are missing and some are simply obsolete. To determine what should be changed in my program I would have to make it available to the wider public, gather some feedback from the users and then decide how the program should be improved. However, even now, I can say which sections need some additional work on them: 1. The speed of the program needs improvement. I have identified the problem as associated with the regular expressions libraries. 2. The configuration of the program should be more flexible. From the point of view of the architecture of the program it is not difficult to do, as the crucial variables determining the operation of the program are located in one place. Though, the user should be able to control all of them by changing only the configuration files, not the source code. 3. The above mentioned files should be well documented, for an end-user to be able to modify them for their needs without any problems. 4. My application doesn’t allow the player (neither human, nor AI) to replace their tiles with the ones from the sack. Replacing tiles is a vital part of the Scrabble game and should be definitely implemented in my game. 5. It is not possible to check the values of specific letter from the level of the application. The user must have an access to either a physical Scrabble game or the Internet to check those values. Although theoretically they can do it by reading the configuration files, it is not a 21

j stands for Java http://pages.google.com/ 23 http://www.google.com/a/ 22

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convenient way of doing so, therefore a feature of showing the letters values should be implemented.

 

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Analysis of the inspiration, research and influences guiding the work  I managed to achieve the goal I set myself at the beginning of the project. This was possible because of the fact that I tried to follow strict procedures, which were guided by the Middle Years Programme Areas of Interaction. As I didn’t know how to program in Java before this project, the main problem met during its development was learning this programming language. The approach I took towards this task was relatively uncommon. However, deciding to actually learn the language in course of the work on the application can be now perceived to have been a good choice, which had saved me quite a considerable amount of time. Not only was my project is strictly connected with technology as such, but I had also applied it in the area of cooperation with my supervisor. A very good example may be the constantly available on the Internet logbook, which could be accessed by my supervisor at any time to check my progress on the work. An interesting remark I made during the project is that despite my profound interest in all the computer-related matters and even the nature of the project, the most reliable sources I used virtually all the time were paper books. It is a very important thing to appreciate the value of a well-checked, carefully designed source of information the Internet is not able to fully provide at this level of its development, at least still in some areas, ironically computer science being one of them. The conclusion is that firstly paying for knowledge in many cases will mean value for money and secondly that Internet is not yet an indispensable medium, despite my immense admiration for its great design and community.

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Conclusion  The most important thing concerning my Personal Project is the fact that I managed to produce it. It simply meets the demands it was appointed – it is possible to play Scrabble with my application. I must admit that finishing the whole task (and many smaller tasks set up within the frames of the Personal Project) gave me a lot of satisfaction. This feeling of achieving a very hard goal, many people assured me was too hard for me, is certainly what made the project worth doing. Basically, I can now say that I truly know what is hidden behind the idea of Homo Faber, the leading Area of Interaction present in my Personal Project. Though, the satisfaction derived from the work is not the only positive effect my project has caused. The potential social meaning of it should be considered. Starting from the basics, it is not only free but also open source, so all the code I wrote can be reused in any other non-commercial or commercial project, under the very liberal terms of the MIT License. Secondly, computers are taking over increasingly big parts of our life. As a result, traditional games are replaced by their new computersbased equivalents. Sometimes the new ones are as valuable as their predecessors, computer Role Playing Games may serve as an example, though very often the today’s generation games are simply less and less demanding or developing. Therefore, creating a Scrabble-playing application may be seen as an attempt to make traditional games once again attractive to the younger generation, of which I am obviously a part. However, the social significance of my product should not be exaggerated. It is still a not very efficient and in fact amateur piece of software. The AI is quite simple and the general performance of the application, as far as its speed is concerned, is poor on slower computers. It is obvious, because I simply am not a professional programmer. Therefore, the focus on the Community and Service aspect of my work could be considered really significant if the program had real use, i.e. was a truly good piece of computer software. Though some of friends to whom I have shown the program admitted that they really enjoyed playing the game, so some goals in the CaS area of my work have been surely achieved. Concluding, I must say that my Personal Project, although unfortunately not having much real-life use, has been a really developing task for me. It helped me in improving my logical thinking skills. Explaining the work of the game’s engine made me express my thoughts and ideas in a more comprehensive way. Finally, managing to do the work assured me that I am able of achieving the goals I set myself. This is what gave me the highest satisfaction and made my Personal Project worthwhile. Word count: 4211

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Bibliography  Eckel, Bruce. Thinking in Java. Trans. Przemyslaw Szeremiota. 4th ed. Gliwice: Helion, 2006. Lis, Marcin. Java. Leksykon Kieszonkowy. Gliwice: Helion, 2005. Lis, Marcin. Praktyczny Kurs Java. Gliwice: Helion, 2004. Lis, Marcin. Tablice Informatyczne. Java. Gliwice: Helion, 2004. Shavor, Sherry, Jim D'anjou, Scott Fairbrother, Dan Kehn, John Kellerman, and Pat McGarthy. Java Developers Guide to Eclipse. Trans. Adam Bochenek, Piotr Rajca, and Jaromir Senczyk. Gliwice: Helion, 2005.

 

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Appendices  A screenshot of the jCreator development environment working on Windows .................................... 16  A screenshot of the Eclipse development environment working on Mac OS X ................................... 16  Potential word inputs to be updated after inserting a new word on the gameboard .............................. 17  A sample user-application interaction ................................................................................................... 17  A list of commands available in the program ........................................................................................ 18  The BSD License .................................................................................................................................. 18  GNU General Public License summary from Creative Commons........................................................ 19  The MIT License ................................................................................................................................... 19  A screenshot of the application's website – jscrabble.kundziad.net ...................................................... 20  A screenshot of a sample human player turn on Mac OS X.................................................................. 21  A screenshot of one game’s results on Mac OS X ................................................................................ 22 

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Figure 1: 1 A screenshott of the jCreattor developmen nt environmen nt working on W Windows

Figure 2: 2 A screenshoot of the Eclipse developmentt environment working on M Mac OS X

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Figure 3: Potential word inputs to be updated after inserting a new word on the gameboard 0

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10 11 12 13 14

E

L

T

E

R

G

0 1 2 3 4

R

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E

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A

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C

A

N

A

C

8

C Q

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U

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13 14

Figure 4: A sample user-application interaction * * * Start of Konrad's turn. Your rack: [e, t, f, g, n, r, i] check ring wahtever 1. ring - valid 2. wahtever - invalid insert 7 7 h ring [........................] You scored 8 point(s). finish turn Your rack after drawing new tiles: [e, t, f, g, j, p, e] * * * End of Konrad's turn. (70 s) Konrad: 8 Another Player: 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

0 # . . . . . # . . . . . #

1 . ~ . . . = . . . = . . . ~ .

2 . . ~ . . . . . . . ~ . .

3 . . ~ . . . . . . ~ . . -

4 . . . . ~ . . . . . ~ . . . .

5 . = . . . = . . . = . . . = .

6 . . . . . . . . . . .

7 # . . . . . r . . . . . #

8 . . . . . i . . . . .

9 10 11 12 13 14 . . - . . # = . . . ~ . . . . ~ . . . . ~ . . . ~ . . . . = . . . = . . . . - . . n g - . . # . . . - . . = . . . = . . ~ . . . . . . ~ . . . . . ~ . . = . . . ~ . . . - . . #

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Figure 5: A list of commands available in the program insert X Y h/v WORD

finish turn finish game = ~ #

insert a sequence of tiles (X - the row of the first tile, Y - the column of the first tile, h/v describes the direction of the word, WORD - the uncapitalised word you want to insert, capitalise letters you want your blank tiles to cover), e.g.: insert 7 5 H libeRty finish your current turn (if you haven't made any input - it means you give up as for now) instantly finish the game and present results based on current points double triple double triple

letter value letter value word value word value

check WORD1 WORD2... check if the provided words are in the dictionary check REG_EXP return all valid words that satisfy the regexp, e.g.: check [degw][alqr]...[aeghrx] show rack show gameboard show results help

show show show show

your rack the gameboard the results of all players this help

set premium on set premium off

turn showing premium tiles on turn showing premium tiles off

Figure 6: The BSD License Copyright (c) , All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. Neither the name of the nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

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Figure 7: GNU General Public License summary from Creative Commons The GNU General Public License is a Free Software license. Like any Free Software license, it grants to you the four following freedoms: 1. 2. 3. 4.

The freedom to run the program for any purpose. The freedom to study how the program works and adapt it to your needs. The freedom to redistribute copies so you can help your neighbour. The freedom to improve the program and release your improvements to the public, so that the whole community benefits.

You may exercise the freedoms specified here provided that you comply with the express conditions of this license. The principal conditions are: You must conspicuously and appropriately publish on each copy distributed an appropriate copyright notice and disclaimer of warranty and keep intact all the notices that refer to this License and to the absence of any warranty; and give any other recipients of the Program a copy of the GNU General Public License along with the Program. Any translation of the GNU General Public License must be accompanied by the GNU General Public License. If you modify your copy or copies of the program or any portion of it, or develop a program based upon it, you may distribute the resulting work provided you do so under the GNU General Public License. Any translation of the GNU General Public License must be accompanied by the GNU General Public License. If you copy or distribute the program, you must accompany it with the complete corresponding machine-readable source code or with a written offer, valid for at least three years, to furnish the complete corresponding machine-readable source code. Any of the above conditions can be waived if you get permission from the copyright holder. Your fair dealing and other rights are in no way affected by the above.

Figure 8: The MIT License Copyright (c) Permission is hereby granted, free of charge, to any person obtaining a 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.

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Figure 9: A screenshot of the application's website – jscrabble.kundziad.net

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Figure 10: A screenshot of a sample huma an player turn n on Mac OS X

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Figure 11: A screenshot of one gamee’s results on Mac OS X

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