Questions tagged [language-design]
Questions involving the design and structure of programming languages.
468
questions
3
votes
4answers
146 views
Is there a cancel after certain amount of time try catch type of block?
I'm going through a beginner programming learning guides and the teacher brings up the try catch block paradigm.
The code you put in the try block is run and if an error happens the code in the catch ...
8
votes
1answer
315 views
What type of syntax notation is this?
SQL Server documentation uses this notation, which is very easy to understand and consume. Is this a BNF Syntax Diagram? Or is this a different type of notation?
Source: SQL server documentation page ...
9
votes
6answers
853 views
Do any programming languages use types as values? Would there be any point?
The standard way that types are handled in programming languages that have such a concept, is that they are:
removed entirely at compile time and are just used to determine memory layout, function ...
-1
votes
1answer
58 views
Appropriate base type for simply typed lambda calculus
Given the following hypothetical programming language:
Intended for practical programming
A simply typed lambda calculus (STLC)
All objects are functions, based on Church encodings
I am aware that ...
4
votes
5answers
596 views
Why don't languages like C have NAND operators?
I know that some golfing languages like APL have a dedicated NAND operator, but I'm thinking about languages like C, C++, Java, Rust, Go, Swift, Kotlin, even instruction sets, etc. since these are the ...
-1
votes
3answers
277 views
Why are constants declared with `let`?
A few weeks ago, I went on Udemy course on Swift, the instructor mentioned that constants are called let in Swift because it's standard in OOP (JavaScript uses it for example).
I know this may seem ...
58
votes
9answers
7k views
Why do “checked exceptions”, i.e., “value-or-error return values”, work well in Rust and Go but not in Java?
Java has "checked exceptions", which force the caller of the method to either handle an exception or to rethrow it, e.g.
// requires ParseException to be handled or rethrown
int i = ...
-1
votes
1answer
157 views
What advantage is gained by continuing to not provide an UPSERT statement in T-SQL (or any given major SQL dialect)?
This question is asking about a generally applicable engineering principle. It is using T-SQL as a specific example, but the question is about the engineering principles behind major SQL dialects in ...
3
votes
0answers
64 views
Choosing the design of a scientific DSL: purely or impurely functional?
My aim is to create a language specific to the scientific field (which would be used mainly in the field of machine learning and physics) which would be based on the functional paradigm, a paradigm ...
5
votes
5answers
307 views
Reasons to use (and not to use) a repeated delimiter to escape that delimiter?
For the designer of a language syntax, what are some reasons to choose a repeated delimiter to escape that delimiter, instead of having a separate escape character to escape that delimiter. A common ...
1
vote
1answer
66 views
How do covariant parameterized types nested inside invariant parameterized types act?
Here is a concrete example of what I'm asking about:
MutableList[ImmutableList[Object]]
Where ImmutableList is covariant wrt its first parameter, but MutableList is invariant wrt its first parameter. ...
0
votes
4answers
376 views
Why have separate keywords for 'extends' and 'implements' in Java? [closed]
Short answer that I've come to accept:
Firstly, it helps with readability, being able to see which is the superclass apart from interfaces. Secondly, though 'extends' and 'implements' do the same ...
5
votes
1answer
179 views
Real-world scenarios for protected inheritance
C++ supports protected inheritance: A class can derive from a base class B in a way that the "outside" world doesn't see that class "as a B" but the class itself and it's derived ...
1
vote
2answers
193 views
Is there a statically typed programming language that implements Polymorphism without using a superclass or an interface?
Is there a statically typed programming language that implements Polymorphism without using a superclass or an interface (if such implementation is even possible)?
0
votes
1answer
119 views
How to deal with metaclasses in strong-typed language : is it ok to mix classes and metaclasses?
I'm working on a programming language design ans I'm struggling with how I should type the concept of Class.
Let me show you some code to illustrate my problem :
class MyClass
{
}
function ...
2
votes
4answers
190 views
A language design with variable qualifier
I am planning to design a programming language. One challenge I face with is whether it is a good idea to have const as a variable qualifier instead of a type qualifier.
For example in C++:
const int ...
8
votes
4answers
655 views
Why does C++ have classes?
The title is deceptive; the question is really "why does C++ have classes and not only structs?"
Often, people ask why C++ has structs if they are functionally equivalent to classes. The answer is (...
1
vote
1answer
213 views
Can syntactic `await` always be elided?
(This question isn't a duplicate of Why do we need the async keyword? - it's more of the opposite: I'm not questioning the async keyword - I'm asking if compilers could elide the use of await ...
84
votes
11answers
17k views
Why F#, Rust and others use Option type instead of nullable types like C# 8 or TypeScript?
AFAIK, Option type will have runtime overhead, while nullable types won't, because Option time is an enum (consuming memory).
Why not just mark optional references as optional, then the compiler can ...
0
votes
2answers
414 views
In C++, Why do bitwise operators convert 8 or 16 bit integers to 32 bit?
Is there a logical reason why the integer is upgraded to 32+ bits?
I was trying to make an 8bit mask, and found myself a bit disappointed that the upgrade will corrupt my equations.
sizeof( quint8(0)...
4
votes
1answer
306 views
Design decisions behind access modifiers in C#
I'm currently writing a small language of my own, and have been considering the difference between the C++ style, where the access modifier applies to a block of members, and the C#/Java style, where ...
2
votes
1answer
253 views
Why did C++11 add find_if() instead of overloading find()?
Why did c++11 add a separate find_if() instead of simply overloading the existing find()?
Wouldn't overloading the function be sufficient?
0
votes
4answers
186 views
Language design : use equals symbol = both for affectation and comparison, like in MySQL
I'm currently designing a database query language and I came to wonder what should be the best syntax for the comparison operator.
Most modern languages use ==, but amongst the database languages ...
40
votes
5answers
8k views
What makes a scripting language “embeddable”?
According to my experience, Wikipedia and prior answers, a scripting language is vague category of languages which are high-level (no manual memory management) and interpreted. Popular examples are ...
-4
votes
1answer
158 views
Is it a good idea to use a Parser Combinator to parse unstructured input?
I'm writing a parser that needs to accept unstructured input. By that I mean it needs to take in a raw signal (text, in this case) and look for significant character sequences while accumulating the ...
29
votes
9answers
9k views
In OOP, isn't the 'protected' keyword required?
Some modern languages (e.g. Swift, Dart) do not support the protected access modifier keyword. Swift is a protocol-oriented language, but I've heard that Dart is a completely object-oriented language.
...
52
votes
7answers
11k views
Is it a bad design for a programming language to allow spaces in identifiers? [closed]
Some (link 1, link 2) programming languages allow spaces in their identifiers (e.g. variables, procedures) but most of them don't and instead programmers usually use camel case, snake case and other ...
12
votes
1answer
726 views
Why was “self” chosen over “this” for the name of the first parameter of python methods?
What was the rationale for choosing the name self instead of this when defining class methods in Python?
Yes, of course, you can name it whatever you want - but the widely agreed-upon name for the ...
-3
votes
3answers
205 views
Ideas for a more compact for loop? [closed]
A for loop is quite an important part of a programming language so you don't want to spend a lot of time typing it out every time for prototyping. An example of a quite ugly syntax is:
for(int x=0;x&...
0
votes
2answers
166 views
What is the reason python uses range in for loops?
Is there some philosophical reasoning behind why python uses this syntax:
for x in range(1,11,3):
instead of, for example, the BASIC syntax:
for x = 1 to 10 step 3
If Python is supposed to be more ...
0
votes
1answer
148 views
Are parser generators useful for parsing a shell language?
From my understanding, parser generators accept as input some form of context-free grammar description. The context-sensitive features are handled during semantic rather than syntactic analysis (...
1
vote
1answer
1k views
Storage of global variables
In C, global variables are stored with the program code. I.e. the space to hold them is part of the object file (either in the data or bss section), instead of being allocated during execution (to ...
1
vote
1answer
140 views
What is the BNF (or BNF-like) syntax for a specific number of repetitions?
I would like to write something like
<byte> ::= <bit>*8
to mean that a <byte> is a sequence of exactly 8 <bit>'s.
Is there a way to do this in BNF[1][2] or a widely used ...
14
votes
5answers
3k views
Can every language be categorized as either compiled or interpreted? [duplicate]
As per Wikipedia: A compiled language is a programming language whose implementations are typically compilers (translators that generate machine code from source code). And an interpreted language is ...
3
votes
3answers
392 views
Language design : How to type higher order functions parameters?
I'm trying to design a theoretical programming language and I'm facing a problem with high order functions.
The language is strong-typed, so the way to define a standard function is like so :
...
1
vote
2answers
217 views
Is it possible to bootstrap a transpiled language?
There're multiple topics about bootstrapping a compiled language, languages that are compiled into machine code directly; However, I can't find good explanation about bootstrapping a transpiled ...
2
votes
3answers
317 views
Why are Lisp programs a sequence of S-expressions and not a single list?
This is quite basic question that started puzzling me recently while studying Lisp (and derivatives). I have read some Lisp books and web sites and this subject is somewhat obscured by other Lisp ...
1
vote
3answers
281 views
What motivates the design of the root Object type in Java and C#?
In Java and C#, all classes derive from the root class Object (java.lang.Object and System.Object respectively).
In both languages/libraries this class comes with a set of methods that are inherited ...
2
votes
2answers
339 views
Why does C# type pattern matching use a different variable scoping behavior than traditional switch blocks?
Traditional switch blocks have one scope, so the following throws a compiler error "A local variable or function named 'message' is already defined in this scope":
switch(value)
{
case 1:
...
1
vote
1answer
148 views
Question about Backus-NaurForm (BNF)
To write the grammar for Whole Numbers (0,1,2...) in BNF, we may write:
Number ::⇒ Digit MoreDigits
MoreDigits ::⇒
MoreDigits ::⇒ Number
Digit ::⇒ 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9
For a ...
4
votes
3answers
372 views
Why datatypes are marked as thread-safe instead of procedures?
In Rust, Send (or Sync) marker traits are used to indicate whether a value of a type (or a reference to that) can be worked on within threaded context.
However, it is an attribute of a function or a ...
1
vote
2answers
1k views
What does the colon before the name mean in this JSON like string?
I encountered this string that looks like JSON syntax but I've never seen a property with a colon before it and not with a backwards greater than or equals sign:
Badge {
:id=>36,
:name=&...
-2
votes
1answer
155 views
Are there languages/syntaxes for representing graphs? [closed]
S-expressions are a well-known way of describing trees in high-level code.
Is there something similar for describing graphs?
The two closest things I've found are DOT and Ko. Both aren't quite what ...
10
votes
2answers
882 views
How could thread safety be provided by a programming language similar to the way memory safety is provided by Java and C#?
Java and C# provide memory safety by checking array bounds and pointer dereferences.
What mechanisms could be implemented into a programming language to prevent the possibility of race conditions and ...
2
votes
2answers
327 views
Definition of intrinsic in language design
I just started looking into programming language design and came across the term intrinsic but could not find any good definition of this anywhere.
I hope that someone here can help me with a good ...
1
vote
2answers
448 views
Why do malloc and calloc have different signatures?
malloc and calloc have these signatures:
void* malloc( size_t size );
void* calloc( size_t num, size_t size );
They do basically the same thing. Both allocate a chunk of memory of the specified size ...
-1
votes
4answers
315 views
Is simplifying overloading always a good thing?
In comments on In C++ do you need to overload operator== in both directions? Story teller waxes enthusistic about the simplified oveloading provided in c++20 with the <=> operator.
That's why ...
3
votes
3answers
832 views
From a language design perspective, is the reference type in C++ mis-designed
Besides the fact that all primitive types of C++ are copy assignable except the reference type, it also doesn't play well with containers or any other parts of the language where copy-assignable ...
2
votes
0answers
1k views
Division by zero Java [closed]
The behavior of Java is explained in this topic.
But, is Infinity useful for something?
Float:
public class DivisionByZeroFloat{
public static void main(String[] args) {
System.out....
3
votes
1answer
387 views
Java - What is the “schism” between interfaces and classes that James Gosling talked about? [closed]
Recently, I've stumbled upon an old interview with Dennis Ritchie, Bjarne Stroustrup and James Gosling, published back in 2000. Each of them talked about the language they were most involved with, ...
