I hope reading this book will be fun. Of all the languages I know, I like Lisp the best, simply because it’s the most beautiful. This book is about Lisp at its lispiest. I had fun writing it, and I hope that comes through in the text.
— Paul Graham
2011.07.01 Friday ACHK
Asperti and Longo [1]: “The basic premise of category theory is that every kind of mathematically structured object comes equipped with a notion of [ : : : ] transformation, called `morphism’, that preserves the structure of the object.”
— A Gentle Introduction to Category Theory
— Maarten M. Fokkinga
2011.06.23 Thursday ACHK
Google had become a big company by thinking like a small company.
— In The Plex: How Google Thinks, Works, and Shapes Our Lives, p.272
2011.06.22 Wednesday ACHK
The Haskell Platform is a collection of software-packages, tools and libraries, which is to create a common platform for using and developing applications in Haskell. With the Haskell Platform, Haskell follows the same principle as Python: “Batteries included”.
— Wikipedia on Haskell Platform
The quality of a programming language itself is only one component in the ability of application writers to get the job done. Programming languages can succeed or fail based on the breadth and quality of their library collection.
— Haskell: Batteries Included
— Duncan Coutts, Isaac Potoczny-Jones and Don Stewart
2011.06.20 Monday ACHK
… it wouldn’t surprise me if much of the category theoretic ‘metaphysics’ gets done by computer science people and physicists.
— David Corfield
2011.06.14 Tuesday ACHK
diff 4
The version history is paired with the use of delta encoding technology. To conserve bandwidth and time, if a file in a user’s Dropbox folder is changed, Dropbox only uploads the pieces of the file that are changed when syncing.
— Wikipedia on Dropbox (service)
2011.06.07 Tuesday ACHK
If you wanted to have the perfect life, the thing to do would be to go to grad school, secretly write your dissertation in the first year or two, and then just enjoy yourself for the next three years, dribbling out a chapter at a time. This prospect will make grad students’ mouths water, but I know of no one who’s had the discipline to pull it off.
— Paul Graham
2011.05.29 Sunday ACHK
Google is the “next Google”.
— Me@2011.05.26
— inspired by Seth Godin
2011.05.26 Thursday ACHK
DDJ: In the presentation before the awarding of the Japan Prize today, you were quoted on the distinction between research and development. [The former, Thompson stated, was directionless, whereas development had a specific goal in mind.] So in that context, is Go experimental?
— Interview with Ken Thompson
— By Andrew Binstock, May 18, 2011
2011.05.24 Tuesday ACHK
…, he described his concept of how compressing data was equivalent in many ways to understanding it.
— In The Plex: How Google Thinks, Works, and Shapes Our Lives, p.100
2011.05.24 Tuesday ACHK
Haskellers never use loops – Instead, they either use recursion to do looping, or they use functions like map that take other functions as parameters.
— Conrad Barski, M.D.
2011.05.22 Sunday ACHK
David A. Wheeler has proposed a counter to this attack using an approach he calls “diverse double-compiling”, which uses techniques adapted from compiler bootstrapping. This involves re-compiling the source of the compiler through another independently-written and generated “trusted” compiler, and then using the binary generated from this to recompile the original compiler again, and then comparing the binary generated from this second compilation with that generated from using the original compiler to recompile itself directly.
— Wikipedia on Backdoor (computing)
2011.05.16 Monday ACHK
Programming languages should be designed not by piling feature on top of feature, but by removing the weaknesses and restrictions that make additional features appear necessary.
— The Scheme standard
2011.05.08 Sunday ACHK
So you end up with a world in which high school students think they need to get good grades to get into elite colleges, and college students think they need to get good grades to impress employers, within which the employees waste most of their time in political battles, and from which consumers have to buy anyway because there are so few choices.
Imagine if that sequence became a big, straight pipe. Then the effects of being measured by performance would propagate all the way back to high school, flushing out all the arbitrary stuff people are measured by now. That is the future of web startups.
— Paul Graham
2011.04.29 Friday ACHK
MapReduce is a framework for processing huge datasets on certain kinds of distributable problems using a large number of computers (nodes), collectively referred to as a cluster (if all nodes use the same hardware) or as a grid (if the nodes use different hardware). Computational processing can occur on data stored either in a filesystem (unstructured) or within a database (structured).
“Map” step: The master node takes the input, partitions it up into smaller sub-problems, and distributes those to worker nodes. A worker node may do this again in turn, leading to a multi-level tree structure. The worker node processes that smaller problem, and passes the answer back to its master node.
“Reduce” step: The master node then takes the answers to all the sub-problems and combines them in some way to get the output — the answer to the problem it was originally trying to solve.
— Wikipedia on MapReduce
2011.04.27 Wednesday ACHK
By abstracting away the very concept of looping, you can implement looping any way you want, including implementing it in a way that scales nicely with extra hardware.
Without understanding functional programming, you can’t invent MapReduce, the algorithm that makes Google so massively scalable. The terms Map and Reduce come from Lisp and functional programming. MapReduce is, in retrospect, obvious to anyone who remembers from their 6.001-equivalent programming class that purely functional programs have no side effects and are thus trivially parallelizable.
The very fact that Google invented MapReduce, and Microsoft didn’t, says something about why Microsoft is still playing catch up trying to get basic search features to work, while Google has moved on to the next problem: building Skynet^H^H^H^H^H^H the world’s largest massively parallel supercomputer. I don’t think Microsoft completely understands just how far behind they are on that wave.
— Can Your Programming Language Do This?
— Joel Spolsky
2011.04.22 Friday ACHK
No one cares what operating system you run as long as it stays up.
— Bruce Perens
That’s why the best choice of software is often no software — and barring that, as little software as you can possibly get away with, and even then, only from the most reputable and reliable sources.
— Coding Horror
— by Jeff Atwood
The greatest of rulers hardly dwells upon the minds of his subjects,
Lesser than this they forever draw near and laud him with great praise,
Lesser than this the people are held in his frightening awe and fear,
Lesser than this the people revile and curse him.
太上，下知有之；
其次，親而譽之；
其次畏之；
其次侮之。
— Laozi (Wikisource translation)
2011.04.16 Saturday ACHK
People strongly tend to think probability is evenly distributed across as many unknowns as are present, whether it is or not (Fox and Levav, 2004:637).
— Wikipedia on Monty Hall problem
2011.04.11 Monday ACHK
When you think about it, love is just another search problem. And we’ve thought about it. A lot. Google Romance is our solution.
— Google Romance
.
.
2011.04.03 Sunday ACHK
Peirce’s law in logic is named after the philosopher and logician Charles Sanders Peirce. It was taken as an axiom in his first axiomatisation of propositional logic.
In propositional calculus, Peirce’s law says that ((P→Q)→P)→P. Written out, this means that P must be true if there is a proposition Q such that the truth of P follows from the truth of if P then Q. In particular, when Q is taken to be a false formula, the law says that if P must be true whenever it implies the false, then P is true. In this way Peirce’s law implies the law of excluded middle.
Peirce’s law does not hold in intuitionistic logic or intermediate logics and cannot be deduced from the deduction theorem alone.
Under the Curry-Howard isomorphism, Peirce’s law is the type of continuation operators, e.g. call/cc in Scheme.
— Wikipedia on Peirce’s law
2011.04.02 Saturday ACHK
Physics Town 
You must be logged in to post a comment.