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.
876
questions
1
vote
0answers
5 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
19 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
33 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
0answers
32 views
What is the future of Language Design?
What is the future design of Programming Languages?
I have heard that compilers is going to become more integrated with editors and Browsers?
Are we moving to a future with less code in Language ...
-3
votes
1answer
39 views
Why the concept of “ a C program returns a value” has been introduced, how this concept is connected to concept of mathematics
A C function returns a value always. What does it mean.
-3
votes
0answers
23 views
0
votes
1answer
21 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
42 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 ...
-3
votes
0answers
36 views
How the property of convergence or divergence of a mathematical function is used in the design of body of a program in a compiler like C [closed]
A function in C returns a value how this aspect of C Programming is concern with convergence and divergence of a function in maths.
0
votes
1answer
39 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
74 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
13 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
64 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? ...
2
votes
0answers
78 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
40 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
813 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
199 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
33 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 ...
-2
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
28 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
24 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
42 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
123 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 ...
4
votes
1answer
73 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
73 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
45 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
49 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
23 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
32 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 ...
26
votes
3answers
6k views
Is there any reason why the modulo operator is denoted as %?
I would like to know if there is any reason why many programming languages use the notation % for the modulo operator?
It is used in the most "famous" ...
0
votes
0answers
22 views
formal definition of lexical scope
I wonder if there is a formal definition of lexical scope so that people can prove things with respect to it, for example, that an interpreter implements lexical scope. You may ask what level of ...
0
votes
1answer
15 views
Subclass specification
From http://web.mit.edu/6.031/www/fa19/classes/12-interfaces-enums/#implementing_generic_interfaces
"That means B is only a subtype of A if B’s specification is at least as strong as A’s ...
1
vote
0answers
18 views
Unifying object oriented language
I'm not sure if this is off-topic but I was thinking about the following: many modern (object-oriented) programming languages are very similar at their core, i.e. they share language features like ...
0
votes
0answers
28 views
Function notation/mapping for this type of functions?
In short, what is the proper function notation/mapping for this type of functions?
From Wikipedia regarding maps:
In the communities surrounding programming languages that treat functions as first-...
2
votes
1answer
69 views
What are the most used statements in programming (ranked)?
I was wondering if there are any resources for a study/ranking of the most frequently used statements (by statements I mean assigning, invoking, instantiating etc, like in C#) in programming overall (...
-1
votes
1answer
20 views
Random numbers with condition in matlab
I need ’n’ random numbers that:
each one is bigger than ‘a’
their sum is smaller than ‘b’
How can I have that in Matlab?
0
votes
0answers
25 views
Are there any beginner-friendly courses teaching how to create a programming language?
There are many excellent step-by-step courses (free and paid) teaching you how a specific programming language works and how to use it to create applications. I've benefited a lot from these courses.
...
9
votes
1answer
870 views
Monad in Haskell programming vs. Monad in category theory
I have a question about concept of monad used in Haskell programming
and category theory in math.
Recall in Haskell a monad consists of following components:
A type constructor that defines for each ...
0
votes
1answer
50 views
I want to learn more about computer science. Where should I start?
Hello computer scientists,
I am a mathematician. I have taken some undergraduate courses in C++, Python, assembly language, boolean algebra, logic, graph theory, etc. I would like to learn more about ...
2
votes
1answer
74 views
How does the undecidability of Extensional Martin-Löf Type Theory apply to real type-checking compilers?
It is claimed in many sources (for example, here) that adding a rule like "if Id(X,Y) then X really equals ...
2
votes
1answer
26 views
How would you model Rust procedural macros?
In Rust programming language one can write a compiler extension function that works on abstract syntax tree, effectively modifying source code before it gets converted into machine instructions.
In ...
-1
votes
1answer
34 views
Java programming object terminology
Say there is a class called Person. Then in the following expression :
Person human = new Person()
Which is the "reference&...
-1
votes
1answer
48 views
doubts on cin and scanf [closed]
i spent literally 5hrs trying to figure out, why the value of n is 1 for my second test case ( which begins at line 12 ) , but i am unable to, could you help me with that?
...
0
votes
1answer
23 views
Can you use binary files to reverse engineer cpu architecture?
I wanted to know if it was possible to add code directly to a computer without an operating system or any programming language. To do that, I thought that maybe I could use the binary files to reverse ...
2
votes
1answer
74 views
Type-checking function calls with functional subtyping
I'm relatively new to the topic. Suppose that you want to type-check an expression of the form f(a), i.e. a function call. Assuming that all the declarations are ...
