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.
836
questions
2
votes
1answer
41 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 ...
1
vote
1answer
17 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
0answers
28 views
key benefit of using container?
I'm not a guy who has computer science related background, just curious about the container technology and of course I did some googling to see what container is.
hope this is the correct site for ...
-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
39 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
21 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
68 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 ...
0
votes
0answers
20 views
How would I convert separate digits to an actual number?
In Dr. Racket, how would I combine the digits w, x, y, z to wxyz (for example 3, 7, 8, 9 to 3,789)?
I haven't gotten very far on this:
(define digits-to-numbers w x y z)
0
votes
1answer
23 views
what are the weakest preconditions of these following statements
what is the meaning of postcondition and weakest postcondition in terms of programing and what are weakest postconditons of following statements.
...
0
votes
0answers
22 views
Regular expressions accepted by programming languages but are not regular [duplicate]
The below definition of Regular Language is given in Wikipedia.
In theoretical computer science and formal language theory, a regular language (also called a rational language) is a formal language ...
19
votes
5answers
4k views
What is the formal, rigorous definition of a programming language?
In programming language theory, people study the theory behind programming languages. But I have never heard any formal definition of programming languages themselves. What is the formal definition, ...
3
votes
0answers
47 views
Semantics of “write-once” variables for complex data structures
Question
My use case for what is described below is not a language or compiler implementation, but finding a reasonable semantics for this feature in a an abstract calculus.
Ideally, you give me a ...
0
votes
2answers
56 views
Are C standard library functions considered part of C programming language
Do we consider functions like printf part of C language even if it's not a keyword in it.
0
votes
1answer
35 views
First-order mutual-recursive functions Turing-complete or incomplete?
Assume we have a C-like programming language with no pointer/heap semantics (i.e. there is no concept of memory; everything is on the stack). The only datatype supported is Integer, but suppose the ...
1
vote
1answer
42 views
Terms for different models of sum types
There seem to be at least a couple different possible ways of modeling sum types in a type system, but I haven't been able to find consistent terms for referring to them:
A sum type is formed from a ...
1
vote
1answer
40 views
In the dataflow programming paradigm programs are modeled as directed graphs. Are the edges of the graph variables? And are the vertexes functions?
As I understand it in dataflow programming, programs are structured as directed graphs, an example of which is below
Is it true to say that the arrows (or edges) represent the variables within a ...
3
votes
0answers
58 views
What's the meaning of linguistics?
In the programming language theory world, there are two important terminologies, i.e syntax, and semantics.
I can understand these two terminologies:
syntax is about sentence's structure (e.g. a valid ...
1
vote
2answers
40 views
What programming language should I use to run physics simulations of CO2 being absorbed by different materials?
I want to model the absorption of CO2 with multiple different materials such as cement, limestone, wood, etc? I know Matlab is capable of these types of physics simulation according to this research ...
2
votes
1answer
50 views
How to view Graph Reduction/Graph Representation for a Haskell program?
I know that under the hood, for a Haskell program, the GHC compiler uses graph reduction for optimization. Is there any way to view this graphical representation of the program? I haven't been able to ...
0
votes
0answers
58 views
What does it take to create a new programming language and its toolchain?
I am super novice to this topic, so my apologies if my question looks completely nonsense to you all!
Imagine you want to create a new programing language that transpiles to a more common high/low-...
0
votes
0answers
25 views
Exceptions from exceptions, does such a thing exist?
I am intrigued: In many languages there are both normal control flow and exceptions.
But I never saw "an exception from an exception" or "an exception from an exception from an ...
16
votes
5answers
7k views
Why do more powerful programming languages tend to have slower implementations?
I was reading this article. The author talks about "The Blub Paradox". He says programming languages vary in power. That makes sense to me. For example, Python is more powerful than C/C++. ...
0
votes
0answers
24 views
Question regarding definition of recursive function
According to Wikipedia, and also a very common definition of a recursive function found in several books, "functions that call themselves from within their own code". I agree that this solves the ...
6
votes
3answers
844 views
Where should I start to understand how computers work? [duplicate]
I am interested in how computers work but I have no idea how the concept of 0's and 1's converts to making possible for people to control a computer by programming. I would like to understand from ...
1
vote
2answers
101 views
Do there exist coding languages where the halting problem is solvable but not trivial
Does there exist a coding language where
1. It is always possible to determine whether a computer program will halt or run forever. And
2. The answer is not always yes. (or always no)
So languages ...
3
votes
1answer
69 views
How to prove that replacing a character in a string in both C and JavaScript is equivalent?
I would like to try some different proofs, specifically in proving equivalence of the implementation of some feature in two different programming languages (C and JS in this question).
This is about ...
2
votes
1answer
61 views
Difference between assignment, binding, and substitution?
I am trying to understand the difference of assignment, binding, and substitution. I know the three things are related, but to me it's not exactly clear what word refers to what. Example, illustration,...
3
votes
1answer
42 views
How to write a custom editor for a new programming language? [closed]
Let's say I've finished my compiler for my new language. Next step is write a custom editor with syntax highlighting (type checking and semantic can wait), is there a cookbook or any kind of guidance ...
2
votes
3answers
89 views
Uncurrying and Polymorphism
How do we uncurry functions when they are polymorphic? For example, is it possible to uncurry the following types? If so what is the uncurried type?
$\forall X. X \rightarrow int \rightarrow X$ ?
$...
1
vote
0answers
44 views
Lambda calculus and runtime inspection of the term
This is possibly related to reflection and quoting but I don't want to assume anything beforehand. Here is my requirement.
My typed lambda calculus (Curry style) is a simpler variant of Calculus of ...
3
votes
4answers
4k views
Do you ever “download” a language?
When one "downloads" a language (say, downloading the python file, or doing apt-get ruby or something), is it always the ...
0
votes
0answers
16 views
Term for language that abstracts program location?
What is the technical term that describes a programming language that abstracts (or at least largely abstracts) the machine location of programs? I’m thinking here specifically of the evolution of ...
21
votes
6answers
2k views
Halting problem theory vs. practice
It is often asserted that the halting problem is undecidable. And proving it is indeed trivial.
But that only applies to an arbitrary program.
Has there been any study regarding classes of programs ...
0
votes
0answers
36 views
What are symbols and symbol references in Scheme?
Practical Foundation of Programming Languages by Harper distinguishes concept "symbol" and concept "symbol reference" which refers to a symbol:
Chapter 31 Symbols
In this chapter, we consider ...
0
votes
0answers
29 views
How is a symbol “given meaning by a family of operations indexed by symbols”?
Practical Foundation of Programming Languages by Harper says:
Chapter 31 Symbols
A symbol is an atomic datum with no internal structure. Whereas a
variable is given meaning by substitution, ...
0
votes
0answers
16 views
What are the implementation strategies for multiple dispatch: class-based, or method-based organization, or either?
Regarding classes and methods, Practical Foundation of Programming Languages by Harper says:
Dynamic dispatch is often described in terms of a particular implementation strategy,
which we will ...
0
votes
2answers
58 views
What is the single type in a dynamic typing language?
Regarding static typing and dynamic typing, Practical Foundation of Programming Languages by Harper says:
There have been many attempts by advocates of dynamic typing to
distinguish dynamic from ...
2
votes
1answer
48 views
Do dynamic/static languages associate types or classes to values or variables?
In Practical Foundation of Programming Languages by Harper
There have been many attempts by advocates of dynamic typing to
distinguish dynamic from static languages. It is useful to consider
...
-2
votes
1answer
44 views
What is the time complexity of the following triple nested loop? Kindly solve in term of n
I want to ask that what is the time complexity of this function (triple nested loop)
.Kindly analysis completely so that I can understand.
...
1
vote
1answer
33 views
More the number of for loops greater the problems solved
This is more a formal language theory question.
Imagine a setting where you are given a very basic programming language where variable assignments etc are taken care of without any of the iteration ...
2
votes
1answer
27 views
Interactive programming language minimizing reevaluations
I'm looking for any programming language, DSL, library or pattern for live scripting but minimizing the expressions reevaluation.
Topological sorting provides non-revaluation of expressions.
...
0
votes
2answers
27 views
Error handling in a size_t hashfunction
For school I have a big assignment on hashtables etc. One of the functions is a size_t function where we calculate the hash value. (Keep in mind the structure of every function is given so we are not ...
2
votes
0answers
32 views
Compiling an impure language into a pure stack-based language
For a personal learning and fun project, I build an abstract virtual machine based on a stack. The instructions are simple and act on the top of the stack only. There are also stack operators such as <...
0
votes
0answers
11 views
FOIL system for learning PROLOG rules from facts
I'm trying to use FOIL, a system from the 1990s developed by Ross Quinlan, to learn Prolog rules from facts. However, the input file syntax is tricky for me. Could someone provide me an example input ...
1
vote
1answer
32 views
Type inference with overloading
I am working on a type system supporting overloading. I have a rough idea of how type inference is usually implemented in such a scenario, but I am wondering how - after type inference is completed - ...
0
votes
2answers
23 views
Does hiding variables work in terms of blocks or line-by-line?
Let's assume I have the following code:
declaration of a
declaration of b
..a..b
{
..a..b
declaration of a
declaration of b
..a
}
In this code {} ...
0
votes
0answers
23 views
≤ shown as £; ≥ shown as ³
I have a printed answer to a math problem which has weird symbols on it. I figured out that the symbols were just incorrect renderings of usual symbols. Do you know what might have caused this?
53
votes
1answer
11k views
What is the earliest use of the “this” keyword in any programming language?
I understand the this (or self or Me) is used to refer to the current object, and that it is ...
2
votes
0answers
28 views
Is Event Calculus applied for program verification?
Recently I've read wiki page about Robert Kowalski (Prolog author) and stumbled upon interesting concept of Event Calculus. The wiki article mentions only few applications of this logical language. I ...
1
vote
2answers
68 views
resource on translating imperative programs to functional programs
I'm not asking this question for the purpose of any particular project. Rather, I'm trying to understand how to translate non-trivial programs in imperative style to functional style. By functional ...
