# Все вопросы: [theory]

172 вопросов

**1**

**4**ответов

### Is there a general term for a pairing of tables where one has header information and the other has detail lines?

Is there a general term for a pairing of tables where one has header information and the other has detail lines? For example, a pair of tables describing sales orders, or a pair storing bill of materials data.

**9**

**3**ответов

### Coinduction - clear, concise description

I am studying coinduction(not induction) as part of a class on static analysis. Rummaging around the internet, I am simply not finding clear, concise description of: What coinduction is How coinduction actually proves something(it seems that coinduction is like waving a magic hand in the treatm...

**8**

**11**ответов

### What is the shortest way to write parser for my language?

PS.Where to read about parsing theory?

**14**

**8**ответов

### What is the use of finite automata?

What is the use of finite automata? And all the concepts that we study in the theory of computation. I've never seen their uses yet.

**5**

**6**ответов

### Theory: Compression algorithm that makes some files smaller but none bigger?

I came across this question; "A lossless compression algorithm claims to guarantee to make some files smaller and no files larger. Is this; a) Impossible b) Possible but may run for an indeterminate amount of time, c) Possible for compression factor 2 or less, d) Possible for any compression fa...

**2**

**4**ответов

### How to handle theming of modules in a web application?

I have made a CMS that allows users to choose which modules to show where on the website. I also have templates/themes that define how the site look. The problem I have goes like this: Suppose I have placed a voting booth module on the site. When I press "View results", it will display the resul...

**3**

**9**ответов

### C++ implicitly calling a function When? and How?

I have a couple questions. Are all functions inside of a class member functions? or only the ones preceded by the declaration "friend"? The significance of member functions are that they cannot be accessed by any other classes correct? What is the difference between an implicit and explicit ca...

**7**

**4**ответов

### Secret computing: does such an animal exist?

A question in theory of Computer Science Today I can secretly store files in the cloud (say, amazon s3), by having them encrypted before I store them and decrypt them after I download. The storage provider cannot obtain any information from the stored files - everything is encrypted safely, and ...

**30**

**11**ответов

### Bootstrapping a compiler: why?

I understand how a language can bootstrap itself, but I haven't been able to find much reference on why you should consider bootstrapping. The intuitive answer is that the language you're writing offers utilities that are not found in the "base" language of the compiler, and the language's featu...

**8**

**3**ответов

### Church Numerals: how to encode zero in lambda calculus?

I am learning lambda calculus but I cant seem to understand the encoding for the number 0. how is "function that takes in a function and a second value and applies the function zero times on the argument" a zero? Is there any other way to encode zero? Could anyone here help me encode 0?

**6**

**4**ответов

### what does driver program mean?

there is a quote from Algorithms for Java (sedgwick 2003) p. 135: "we commonly use driver programs when developing or debugging adt iplementations" what is meant by driver program? google just gives me loads of info about programming drivers, clearly not related

**1**

**4**ответов

### Searching through descriptions

There's a movie which name I can't remember. It's about a carnival or amusement park with a horror house and a bunch of teens who are murdered one by one by something with a clowns mask. I've seen this movie about 20 years ago, and it's sequel, but can't remember it exactly. (And also forgot it's...

**4**

**6**ответов

### Efficiency of Sort Algorithms

I am studying up for a pretty important interview tomorrow and there is one thing that I have a great deal of trouble with: Sorting algorithms and BigO efficiencies. What number is important to know? The best, worst, or average efficiency?

**1**

**2**ответов

### OCR - most "different" or "recognizable" ASCII characters?

I am looking for a way to determine the most "different" or "recognizable" N ASCII characters... For example, if N = 10, what would be the most different N characters in the ASCII set from 0x21 to 0x7E? Obviously, the character "X" is very different than "O" (the letter), but "O" (the letter) i...

**0**

**3**ответов

### Esoteric JS Question

Is there any particular reason that this sort of construct would not work in JS? (JSLint does not accept it.) (function(function(){ }){ })() I can see this type of chaining going on forever, or at least as far as one would want/need. Does anyone have any thoughts?

**3**

**9**ответов

### Is it possible to construct a turing-complete language in which every string is a correct program?

Is it possible to construct a turing-complete language in which every string is a correct program? Any examples? Even better, any real-world examples? Precisions: by "correct" I mean "compiles", although "runs without error" and "runs without error, and finishes in finite time" would be interes...

**3**

**1**ответов

### Textual Protocol which is not a regular language?

The usual way to represent way the grammar associated with a textual network protocol is using ABNF. Just like any EBNF-related meta-syntax, ABNF enables to describe context-free grammars. These context-free grammars can represent a non-regular language, right ? The usual way to implement a n...

**3**

**3**ответов

### Combinator logic axioms

I'm carrying out some experiments in theorem proving with combinator logic, which is looking promising, but there's one stumbling block: it has been pointed out that in combinator logic it is true that e.g. I = SKK but this is not a theorem, it has to be added as an axiom. Does anyone know of a c...

**0**

**7**ответов

### What do you do when you encounter a tricky problem?

What do you do when you encounter a programming problem that is really hard for you to solve, and you have no idea yet? Usually, how do you solve it at last? NOTES: Could someone introduce something about problem solving practice?

**1**

**1**ответов

### Saving related records without saving the referenced record first

I'm not sure how to explain this so I am going to try do it as clearly as I can. We have a case logging web app. When one adds a case ticket, one can add contacts and attachments to that ticket. I am trying to find a way for the visitor to fill in the case ticket information, add n contacts an...

**1**

**2**ответов

### What are the optimization networks? Where can I find info?

So, i recently found this term related somehow to neural networks, but I don't find anymore info on this topic, and it seems interesting. Does anybody know where I can find more info for starters on this? thanks in advance

**12**

**4**ответов

### Learning garbage collection theory

I want to learn the theory behind garbage collection. How do i go about it? The obvious answer is - a compiler textbook... The question is, is it necessary to learn lexical analysis, parsing and other stuff that usually precedes garbage collection in a text? In short, what are the prerequisites...

**3**

**5**ответов

### Why do you use a random number generator/extractor?

I am dealing with some computer security issues at the school at the moment and I am interested in general programming public preferences, customs, ideas etc. If you have to use a random number generator or extractor, which one do you choose? Why do you choose it? The mathematical properties, alr...

**20**

**5**ответов

### Why is cloning (in .NET) so difficult?

In the past I had the need to clone objects, only to find that they don't implement a Clone() method, forcing me to do it by hand (create a new instance and copy all properties from the original to the new one) Why isn't cloning as easy as duplicating the memory block the object is allocated in,...

**1**

**4**ответов

### How many possible bugs are there?

A user has to complete ten steps to achieve a desired result. The ten steps can be completed in any order. If there is a bug, the bug is dependent only on the steps that have been taken, not the order in which they were taken (i.e., the bug is path independent). For example: If the user perfo...

**6**

**2**ответов

### General proof of equivalence of two FSMs in finite time?

Does a general proof exist for the equivalence of two (deterministic) finite state machines that always takes finite time? That is, given two FSMs, can you prove that given the same inputs they will always produce the same outputs without actually needing to execute the FSMs (which could be non-t...

**0**

**3**ответов

### Rollback and Preview in a CMS

I am creating a CMS and am using serialize to handle publish and rollback, which seems to work fine. Basically, The normal site tables are what gets displayed and anything not displayed is serialized in a separate table. The problem however is in making the 'Preview' functions work. Since th...

**8**

**6**ответов

### Finding prime factors to large numbers using specially-crafted CPUs

My understanding is that many public key cryptographic algorithms these days depend on large prime numbers to make up the keys, and it is the difficulty in factoring the product of two primes that makes the encryption hard to break. It is also my understanding that one of the reasons that factori...

**4**

**8**ответов

### Should FPGA design be integrated into a Computer Science curriculum?

If computer science is about algorithm development and therefore not limited to the imaginations of Processor vendors, but to the realm of all that is practically computable. Then shouldn't a FPGA, which is almost ideally suited for studying cellular automata, be considered a valid platform upon ...

**12**

**2**ответов

### Practical application of "Bananas, Lenses, Envelopes, and Barbed Wire"?

First of all, the goofy title is directly referencing this paper: http://eprints.eemcs.utwente.nl/7281/01/db-utwente-40501F46.pdf I understand the theoretical value of this, as it models most, if not all, programming semantics. What problems are most efficiently and practically solved with a p...