Questions tagged [programming-languages]
Questions related to design, implementation, and analysis of programming languages. NOT for questions about how to program, which are off-topic on this site.
888
questions
0
votes
0answers
27 views
Is there a simple algorithm for generating unit tests given a function's code? [closed]
Given the abstract syntax tree (AST) of each line of a function's code, I am asked to generate code for that function's corresponding unit tests, similar to what Microsoft's IntelliTest tool does here:...
0
votes
1answer
49 views
How programming languages are capable of handling generic types
How programming languages are capable of handling generics ?
Here is some context on why I got the question.
Constructs like Lists, Dictionaries and Sets in Python can handle any type of data without ...
1
vote
1answer
52 views
What is the formal definition of precedence and associativity in programming language?
The concept of precedence and associativity seems straightforward.
The operator precedence is a collection of rules that reflect conventions about which procedures to perform first in order to ...
1
vote
3answers
60 views
Should I be a good computer scientist to become a great software developer?
As I am headed into a Computer Science major wishing to eventually become a software developer, I wonder this: should I immerse myself in computer science theory and knowledge (data structures, ...
0
votes
2answers
55 views
What is the best book on the theory of programing languages?
I want to learn programming.
I have knowledge of mathematical logic.
So, what I am searching is a book (or varios books) for learning to programming, but I think that a book like one which I imagine ...
-4
votes
1answer
52 views
Is Programming Witchcraft or Actual Magic?
I may sound stupid, but few people say that programming is witchcraft (maybe Joking) as a Christian I Must take it seriously, because I am planning to become Software Architect in the future. Honestly ...
1
vote
2answers
41 views
Loop Invariants: Can someone explain this concept?
I am reading Algorithms Unlocked By Tom Cormen and find this concept a little confusing.
Why is it that we require loop invariants and how does it help in analyzing algorithms?
1
vote
1answer
20 views
Is a constant literal an example of a built-in?
My understanding is that in a programming language, built-ins are bindings that exist without the user having to make them. (Like + to its referent, for example.)
...
4
votes
1answer
62 views
How compiler optimizations create irreducible control flow graph?
I've been looking through research papers and the internet and found many claims that "compiler optimizations can cause irreducible control flow". However, I was not able to find a single ...
1
vote
1answer
38 views
What is “invariants of the code”?
The Wikipedia page for strong and weak typing says:
"Strong typing" generally refers to use of programming language types in order to both capture invariants of the code
What is "...
19
votes
4answers
7k views
How do computers perform operations on numbers that are larger than 64 bits?
There are many reasons why numbers larger than 64 bits must be computed. For example, cryptographic algorithms usually have to perform operations on numbers that are 256 bits or even larger in some ...
1
vote
0answers
30 views
A beginner's question on programs that can search and calculate in very large sets
I am not in the computer science field and was looking for some guidance on books/papers/programs that allow me to learn how to design algorithms for problems that involve very large number of ...
2
votes
1answer
44 views
How does asynchronous operations save time in I/O
I'm reading a book CLR via C# which says how Windows does asynchronous I/O:
To read data from the file, ReadAsync internally allocates a Task object to represent the pending completion of the read ...
2
votes
1answer
58 views
Macros vs lazy evaluation in scheme inspired language
I'm writing a simple scheme inspired interpreter. I'm not calling it a scheme implementation because I don't really want to implement all the standard, only the minimal set of primitives needed to ...
1
vote
1answer
53 views
virtual machine based programming languages vs low level
I took programming lecture it was about C/java and how to build compilers, so I wanted to know.
As far I see, languages like Java/C# are developing their virtual machine CLR/JVM with good base and are ...
0
votes
0answers
28 views
Is the tidyverse a dialect of R?
Usually when I see "programming language dialect" it refers to small variations of a language, such as BASIC dialects or different versions of Lisp.
The tidyverse set of packages form their ...
14
votes
4answers
7k views
Are modern programming languages context-free?
Which language class are today's modern programming languages like Java, JavaScript, and Python in?
It appears (?) they are not context-free and not regular languages.
Are these programming languages ...
0
votes
1answer
37 views
What other implementation styles are there besides compilation, interpretation and transpilation?
Obviously there is JIT but it is basically run-time compilation. There is also implementing things in VHDL or ASIC. But my question is more towards software techniques for program building and ...
1
vote
0answers
12 views
How do bottom up parser evaluate things that need an inherited attribute?
I learned that Bottom up parsers use only synthesized attributes to evaluate semantics. Which makes sense considering that it would be very hard to evaluate an inherited attribute in bottom up ...
2
votes
1answer
81 views
Which would be better for programming using Homotopy type theory Agda or Idris
I'm looking to model data inputs for an artificially intelligent system, which is affected by its internal parts and has feedback loops. I'd like to model it mathematically, using category theory or ...
1
vote
1answer
39 views
Why does universe level restriction behave differently between inductive family and parameterized inductive type without axiom K in agda
An observation when defining List in agda with --without-K enabled:
The following parameterized inductive definition is accepted:...
0
votes
1answer
22 views
BNF syntax for a recursive function?
I'm to write a syntax that will allow for a recursive function, i.e.
f(x) = if x == 0 then x else f(x+1)
Here's one attempt at creating the grammar:
But I don't ...
2
votes
0answers
48 views
Do any industry programming languages use Martin-Löf style identity types?
Most programming languages have some kind of type systems but are there any programming languages widely used outside of academia (in consumer-oriented tech, finance etc.) that have intensional ...
0
votes
1answer
33 views
while loop for bitwise conversion program
int counter(char c){
int count = 0;
while (c!=0){
if((c & 1) !=0)
count++;
c = c >> 1;
}
}
I am trying to understand a ...
0
votes
1answer
45 views
With a list of opcodes for a virtual machine, is it possible to assign a number to every possible program of size n that can be run on that machine?
Say you have some virtual machine with < 100 numbered opcodes that fully specify its behaviour. Is there an easy way to order and enumerate all possible programs of less than n instructions, the ...
0
votes
1answer
45 views
How to do asynchronous programming with only global variables?
If a programming language only supports global variables, is it still possible to use asynchronicity, like callbacks, event-driven programming, other kinds of parallelisation?
How can it be done?
1
vote
1answer
82 views
can a machine generate truly random numbers?
I know that for most programs pseudo-random numbers are sufficient, but there are ways that machines can generate truly random numbers! There are devices that generate unpredictable processes. However,...
0
votes
0answers
21 views
If the load factor is a decimal (say 3.6), what is the length of each chain in a hash table that utilizes separate chaining?
I understand that if the load factor were 2, then the length of the chain would be 2 for each index in the array, but what happens if the load factor is a decimal? Do we round up or down?
1
vote
1answer
78 views
Resources for implementing dependent type theory
I want to implement Martin Löf's intuitionistic type theory in a functional language such as Haskell, preferably also implementing a lexer/parser for the language. How should I start approaching it? ...
3
votes
3answers
140 views
Why do programming languages use call-by-value over call-by-name?
I am reading Software Engineering 1: Abstraction and Modelling by Dines Bjørner. One of the chapters talks a little bit about call-by-value vs call-by-name. In it, the author states that most ...
1
vote
2answers
43 views
Relation between programming languages requiring declaration of variables before use and using the token class $\text{id}$ while parsing
I was going through the text Compilers: Principles, Techniques and Tools by Ullman et. al. where I came across the following excerpt.
Example 4.11. Consider the abstract language $L_1 = \text{ { $wcw$...
5
votes
2answers
828 views
Break keyword outside a loop is syntax error or semantic error?
I am designing a simple compiler for my university project. In my programming language, the break keyword is allowed.
I want to know whether break keyword occurs outside a loop should be a syntax ...
5
votes
2answers
215 views
Regarding Backus' Commentary on von Neumann-style Programming
in John Backus' 1978 FP paper "Can Programming Be Liberated from the von Neumann Style" he says
To help assemble the overall result from single words [von Neumann ie.
conventional mutation-...
1
vote
2answers
38 views
How to evaluate a Kleene's Closure through CFG and attribute grammars
For a CFG with the production rules that can represent a regular expression. How can one calculate all the set of strings that regular expression would produce.
For T = {a, b,*,(,)}
and an arbitrary ...
-1
votes
1answer
34 views
Find the most frequent alphabet appearing in the given string. In case letter with same frequency, choose the one which comes first alphabetically
This is the desired result which I want:
2
votes
1answer
37 views
Fine-grained versioning of entities in programming languages
I have a question related to design, implementation of programming languages. I hope it fits here and apologize if it doesn't.
All or most programming languages version modules (aka packages, ...
1
vote
0answers
26 views
What will be the output when using pass-by-value-result with parameters such n+1?
Let's say a function $f$ is called with parameter $n+1$. Since I use pass-by-value-result, value of formal parameter will be transmitted to the caller's actual parameter at the end of the call. Let ...
2
votes
2answers
46 views
Textbook on formal syntax (and semantics) of programming languages
I'd like to learn about formal syntax of programming languages: how do we describe the syntax of a programming language and how it should be parsed? How do we assign formal semantics to a parsed ...
1
vote
0answers
127 views
How can I simulate nested WHILE loops in a theoretical programming language to show Turing completeness?
PRE-WORK-POST is a theoretical programming language with the following structure, where P,Q and R are LOOP program:
$$\text{PRE} \ P \ \text{WORK} \ Q \ \text{POST} \ R \ \text{END}$$
First $P$ is ...
5
votes
1answer
126 views
Explain the difference between Turing Complete and Turing Equivalence
I'm not sure if I understand the difference between Turing Complete and Turing Equivalent programming languages.
A computational system that can compute every Turing-computable
function is called ...
2
votes
0answers
34 views
What would you do if the author of a published CS article does not respond to code requests? [closed]
Since reproducibility is a major principle or basic norm of scientific experiments, simulations, and computations, what would you do or what to do if the author of a published CS article does not ...
2
votes
0answers
37 views
Understanding the simulate of an IF loop program through a LOOP program
We have the following operation $\text{IF} \ x_i =0 \ \text{THEN} \ P \ \text{END}$. I want to simulate this using a $\text{LOOP}$ program. Here is what I have:
$$\text{IF} \ x_i = 0 \ \text{THEN} \ P ...
3
votes
0answers
45 views
Is there a language which enforces “no escape” of variables?
Many languages with GC perform escape analysis to reduce heap allocations. Is there a language with a "no-escape" construct that tells the programmer during compile time to not escape ...
18
votes
2answers
5k views
Paradox? Pure Prolog is Turing-complete and yet incapable of expressing list intersection?
Pure Prolog (Prolog limited to Horn clauses only) is Turing-complete. In fact, a single Horn clause is enough for Turing-completeness.
However, pure Prolog is incapable of expressing list intersection....
2
votes
1answer
92 views
What is considered being proficient in a programming language?
I am a college student looking to get into industry work soon and want to understand what employers consider 'proficient' when it comes to programming languages. Right now, I understand that to mean ...
3
votes
0answers
47 views
Is there a computer language with optional dependent types?
I'm looking for a computer langauge with "dependent types" but...
The problem with it having a full implementation is that you end up having to write formal type proofs to get even anything ...
1
vote
1answer
54 views
Is there a formalization for the trade-off between the expressiveness and the speed of a programming language?
I do not have a strong background in theoretical computer science, so the terminology I use may not be the most ideal.
Basically the "trend" across programming languages I have noticed is ...
2
votes
0answers
24 views
Coding max as an interaction net
I am reading Yves Lafont's introductory paper Interaction Nets. Early in the beginning he mentions that max cannot be coded as follows
since in this coding it is not possible to choose which argument ...
0
votes
0answers
18 views
What is the Memory Bandwidth Usage in a Program Related to?
We can use performance counter tools to check the memory bandwidth usage while a program is running. I want to ask what is this memory bandwidth related to? What parameters are involved in memory ...
2
votes
1answer
34 views
printf(“%d”,~5); prints out -6 why is that?
I was reading the book "Computer systems: A programmer's perspective" and saw that the operator, "~", is a NOT operator. When I use it to NOT positive integers, it returns the ...
