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Clang Plays Tetris -- Tetris As a C++ Template Metaprogram
New submitter mjvzb writes: Ever wish compiling was more fun? Well, I recently implemented Tetris as a C++ template metaprogram (code at Github). The game is played by recompiling its source, taking player input by compiler flag. The runtime program is only needed to print the game screen to the console and save the game state across compiler runs.
Implementing Tetris in templates is not as horrific as you may imagine, and I've put together a post covering the details. Once you get over the syntax, C++ metaprogramming is just like functional programming.
Implementing Tetris in templates is not as horrific as you may imagine, and I've put together a post covering the details. Once you get over the syntax, C++ metaprogramming is just like functional programming.
About semi-complex programs ending up re-implementing aspects of lisp or smalltalk-- just less elegantly.
I think you've done it!
Who are you to judge that? Maybe he was lost in the depths of suicidal depression, and this project gave him a reason to drag himself out of it. Maybe an alien race will visit the earth and think that this is just so goddamn clever that there's no reason not to share their hyperdrive tech with us. Or whatever. But basically, fuck you and don't worry about what other people choose to do or not do.
Once you get over the syntax, C++ metaprogramming is just like functional programming.
No, the syntax is the entire thing wrong with C++ metaprogramming. It clearly wasn't designed for things like this. To clear up any doubt about the syntax, check out this file. In addition the inscrutable error messages (although those have improved over the past decade). If anyone likes template metaprogramming, I suggest they just use LISP.
That said, this project is really cool. Nice hack mattbierner.
"First they came for the slanderers and i said nothing."
metaprogramming is like functional programming in these senses:
1) Uses lots of recusion
2) Has no variables, only constants. Nothing is mutable.
3) Has functions
Because of 1 and 2, it helps to think in terms of functional programming if you want to do anything substantial.
"First they came for the slanderers and i said nothing."
If only the people who want to take on challenges like this put their skills to something actually useful....... There has GOT to be a better use of your knowledge and skills.
Sometimes people do things for fun........not because they want to please internet critics.
"First they came for the slanderers and i said nothing."
I am mystified how people can read this and not realize it was just a little fun thing to do in his spare time. Or do you spend every waking minute of your life doing serious things with your knowledge and skills?
"Old man yells at systemd"
Say what?
Template metaprogramming is exactly functional programming.
Not only that, C++98 style was completely 100% pure with no mutabe state. You got recuursion and pattern matching (called [partial] specialisation). A class is essentially a function returning a type (well, multiple types) as internal typedefs. And as such functions are very much first class objects.
C++11 added some local mutable state. constexpr functions can now be evaluated at compile time. Those yielding an int can be used as template arguments.
SJW n. One who posts facts.
Go fuck yourself. Really. If you don't realize that this is a toy and a very clever one at that, I'm not sure what to tell you. Sometimes some things are done to scratch an itch, or for fun or something. You can learn an awful lot about how to do things/not do things by playing around with projects like this. Oh right, you are a "serious professional programmer" with ZERO passion for the work you do.
Also you seriously have zero sense of humor. You must be great fun at parties.
Has no variables, only constants. Nothing is mutable.
And... this is the definition of functional programming (referential transparency). So yes - it actually really *just like* functional programming, because it *is* functional programming.
I've done that sort of metaprogramming. Years ago I wrote a compile-time Lisp interpreter. It's a HORRIBLE language.
Look, say you have some advanced feature. You could write a library in scheme - it will take you 1 day to a week.
You could write it in C++ templates. It will have a worse feature set than the scheme version, it will be much less readable (not that scheme is readable) and much harder to use. It will have unusable error messages. And a mockup version will take you months to write.
Getting your mockup embedded in Boost and working well with it will take the help of a bunch of experts and a two or three times as much work.
If you want it included in the Boost libraries, you'll need a couple years of work integrating it and getting it approved.
Horrible.
The title of this article is a little misleading, as this program works fine with the latest release of gcc (5.1) as well...
[No changes, either to the program or the command-line are required, just use "g++" instead of "clang++".]
Presumably it will also work with any compiler that supports a recent-enough version of the C++ standard and its proposed updates (with the command-line options updated accordingly).
We live, as we dream -- alone....
This is the most terrifying and ridiculous thing I've seen in my entire life.
Americans have spent more than a trillion hours watching reality TV. That is far more terrifying and ridiculous than someone playing with a Turing-complete compiler meta-language.
No one should ever have to work with C++ metaprogramming in their work.
He wasn't working.
He was playing.
Then why would they blog about it... and then submit an article to Slashdot describing and linking to their own god dam blog.
Because other people like to see it, and it's really cool. Specifically, if you don't like this kind of thing, you shouldn't be on Slashdot. See also this.
"First they came for the slanderers and i said nothing."
This is the most terrifying and ridiculous thing I've seen in my entire life.
If only the people who want to take on challenges like this put their skills to something actually useful....... There has GOT to be a better use of your knowledge and skills.
It is one of the first things people do in programming - building games. My son is on the verge of learning computing, and he wishes to build a few games. Once these simpler things are achieved, more complex things are easier to do by more people.