• Announcements

    • khawk

      Download the Game Design and Indie Game Marketing Freebook   07/19/17

      GameDev.net and CRC Press have teamed up to bring a free ebook of content curated from top titles published by CRC Press. The freebook, Practices of Game Design & Indie Game Marketing, includes chapters from The Art of Game Design: A Book of Lenses, A Practical Guide to Indie Game Marketing, and An Architectural Approach to Level Design. The GameDev.net FreeBook is relevant to game designers, developers, and those interested in learning more about the challenges in game development. We know game development can be a tough discipline and business, so we picked several chapters from CRC Press titles that we thought would be of interest to you, the GameDev.net audience, in your journey to design, develop, and market your next game. The free ebook is available through CRC Press by clicking here. The Curated Books The Art of Game Design: A Book of Lenses, Second Edition, by Jesse Schell Presents 100+ sets of questions, or different lenses, for viewing a game’s design, encompassing diverse fields such as psychology, architecture, music, film, software engineering, theme park design, mathematics, anthropology, and more. Written by one of the world's top game designers, this book describes the deepest and most fundamental principles of game design, demonstrating how tactics used in board, card, and athletic games also work in video games. It provides practical instruction on creating world-class games that will be played again and again. View it here. A Practical Guide to Indie Game Marketing, by Joel Dreskin Marketing is an essential but too frequently overlooked or minimized component of the release plan for indie games. A Practical Guide to Indie Game Marketing provides you with the tools needed to build visibility and sell your indie games. With special focus on those developers with small budgets and limited staff and resources, this book is packed with tangible recommendations and techniques that you can put to use immediately. As a seasoned professional of the indie game arena, author Joel Dreskin gives you insight into practical, real-world experiences of marketing numerous successful games and also provides stories of the failures. View it here. An Architectural Approach to Level Design This is one of the first books to integrate architectural and spatial design theory with the field of level design. The book presents architectural techniques and theories for level designers to use in their own work. It connects architecture and level design in different ways that address the practical elements of how designers construct space and the experiential elements of how and why humans interact with this space. Throughout the text, readers learn skills for spatial layout, evoking emotion through gamespaces, and creating better levels through architectural theory. View it here. Learn more and download the ebook by clicking here. Did you know? GameDev.net and CRC Press also recently teamed up to bring GDNet+ Members up to a 20% discount on all CRC Press books. Learn more about this and other benefits here.
Sign in to follow this  
Followers 0
Bacterius

Name of a particular property

13 posts in this topic

Hello,

in my library I'm working on, I have a few functions which take (among other parameters) a data buffer, with the property that calling such a function twice in succession, with two data buffers, is equivalent to calling it once with the ordered concatenation of both data buffers. In other words:

F("hello")
F(" ")
F("world")

Is strictly equivalent to:

F("hello world")

Is there a name for such a property? For instance a function such that F(F(x)) = F(x) is called idempotent. I'm asking because I'm tired of describing this property in such a long-winded manner in my documentation, and it would be nice if there was a word I could use to sum it all up efficiently.

 

Thanks!

0

Share this post


Link to post
Share on other sites

Linear?

 

f(x + y) = f(x) + f(y)

 

(although linearity also means f(a*x) = a * f(x)).

 

This seems ok to me

 

print("A"+"B")=print("A")+print("B")

print(5*"A")=print("A"+"A"+"A"+"A"+"A")+print("AAAAA")

0

Share this post


Link to post
Share on other sites

Linear?

 

f(x + y) = f(x) + f(y)

 

(although linearity also means f(a*x) = a * f(x)).

 

That would be fine for a couple of them but many of them do not actually return an output of the same size as the input (or at all) so in those instances "linear" would be meaningless, unfortunately.

 


I don't know of a name, but I can make one up: "concatenation invariant".

 

I like it smile.png

0

Share this post


Link to post
Share on other sites


I have a few functions which take (among other parameters) a data buffer, with the property that calling such a function twice in succession, with two data buffers, is equivalent to calling it once with the ordered concatenation of both data buffers.

I don't think that is a very good idea.

 

When it comes to building a language, make it apply in ALL cases.  Something that applies in only SOME cases is usually a bug.

 

For example, your example

Print("Hello"); Print(" "); Print("World!);

might just happen to be functionally equivalent to Print("Hello World!");

 

But it is not universally true of all string functions.  It is very different from:

PrintLine("Hello"); PrintLine(" "); PrintLine("World!");

The result should be three distinct entries.  It would be functionally equivalent to Print("Hello\n \nWorld!\n");

 

Or consider:

ShowDialog("Hello"); ShowDialog(" "); ShowDialog("World!");

I expect three distinct dialog boxes, not one single dialog box with the strings concatenated.

 

 

 

It is one thing to allow adjacent string literals to be concatenated.  It is quite another thing to not call adjacent functions because their parameters happen to be the same type.

0

Share this post


Link to post
Share on other sites

 


I have a few functions which take (among other parameters) a data buffer, with the property that calling such a function twice in succession, with two data buffers, is equivalent to calling it once with the ordered concatenation of both data buffers.

I don't think that is a very good idea.

 

[...]

 

I don't understand your objection. Perhaps you misread something? He is not saying that this property is universal, only that he has several functions with that property and he wants to know of a short way to describe it. It sounds very reasonable to me...

0

Share this post


Link to post
Share on other sites

Yes, I am not building a language. But some of my library's functions simply behave that way to allow for arbitrary amounts of data to be provided and at any rate, not limited by the amount of data that can be physically present on one invocation of the function (think about a network socket, for instance, you don't know how much data you are going to receive next, you could receive it all in one shot, or one byte each time you check, so you need a way to make it work the same regardless of how much you've got every time you poll the socket - there are other examples of course). Actually everything is quite consistent overall.

 

 

 

How does the documentation for std::cin describe it?

 

It doesn't really say anything, actually. The std::cout version says it "inserts" into the stream. I think the notion of stream might help me describe it, though.

Edited by Bacterius
0

Share this post


Link to post
Share on other sites

Hello,

in my library I'm working on, I have a few functions which take (among other parameters) a data buffer, with the property that calling such a function twice in succession, with two data buffers, is equivalent to calling it once with the ordered concatenation of both data buffers. In other words:

F("hello")
F(" ")
F("world")

Is strictly equivalent to:

F("hello world")

Is there a name for such a property? For instance a function such that F(F(x)) = F(x) is called idempotent. I'm asking because I'm tired of describing this property in such a long-winded manner in my documentation, and it would be nice if there was a word I could use to sum it all up efficiently.

 

Thanks!

 

 

I don't know of a name, but I can make one up: "concatenation invariant". smile.png

 

Buffered concatenation........?

0

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0