Questions tagged [language-design]
Questions involving the design and structure of programming languages.
445
questions
0
votes
4answers
136 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 ...
38
votes
5answers
6k 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
50 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 ...
28
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.
...
51
votes
7answers
10k 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 ...
11
votes
1answer
581 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
162 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
140 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
111 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
114 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
74 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
1k 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 ...
2
votes
2answers
250 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
165 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 ...
0
votes
3answers
239 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
201 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
288 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
108 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 ...
3
votes
3answers
259 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
351 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
129 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
580 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
102 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
237 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
312 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 ...
2
votes
3answers
553 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
357 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
292 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, ...
-2
votes
1answer
138 views
What is the minimum set of operations a language implementation must provide for it to be usable for all applications?
As a fun hobby project, I'm writing a simple bytecode VM and a compiler from a basic high-level language to the said bytecode.
(Offtopic: the compiler is inspired by Jack Crenshaw's awesome tutorial -...
-1
votes
1answer
188 views
The Principle of Allowing One Way to accomplish a Task
What is the official name of the principle, in language design, where the language tries to offer one way of accomplishing a particular task (as opposed to have multiple ways of accomplishing the ...
2
votes
1answer
259 views
I'm moving away from using global variables after 7 years, I need help figuring out the basics
Until recently I was a huge fan of global variables because they are simple and allow building solutions to problems quickly.
At one point I had to make a slight change to my application: it needed ...
2
votes
2answers
274 views
The dilemma of implementing virtual inheritance
I am working on a program language, and I came to the dilemma whether it should support virtual inheritance or not.
As a designer and implementer of the language, including that feature represents ...
9
votes
1answer
252 views
Name of technique for inferring type arguments of a type parameter?
Setup: Let's assume we have a type called Iterator which has a type parameter Element:
interface Iterator<Element> {}
Then we have an interface Iterable which has one method which will return ...
0
votes
1answer
254 views
Do any programming languages let you use other languages without restriction within them?
This may be a stupid question, and it would certainly take one Hell of a lexer, but do any extant programming languages allow you to do something like:
c# (1.2) {
// c# code
}
Perl (5) {
# ...
8
votes
2answers
547 views
Only one number type in language design
I am currently learning about compiler construction and language design and I am thinking about what native datatypes I want to support in my language. Now there is a whole lot of languages that make ...
1
vote
1answer
171 views
How do languages ensure 'interior immutability'?
In C#, i can declare an immutable field on a class using readonly. This works for value types, but if its a reference type, there is nothing stopping me calling methods on the object to change its ...
6
votes
0answers
137 views
Why does GHC represent recursion in Haskell with recursive binders instead of a fixpoint operator?
GHC's Core data type represents recursion with recursive binders in the Let constructor; as I understand it, all let expressions in Haskell are effectively let rec expressions. Why does GHC use this ...
2
votes
1answer
133 views
Mark&sweep GC with automatic freeing resources
Note: I use term "resource" in opposition to memory here, resource here is file, socket, etc.
Is there a language implementation that uses M&S GC (but not necessarily only that kind ¹) that is ...
5
votes
2answers
853 views
Type-based memory safety without manual memory manage or runtime garbage collection? [closed]
Let's say we wanted a typeful, pure functional programming language, like Haskell or Idris, that is aimed at systems programming without garbage collection and has no runtime (or at least not more ...
0
votes
2answers
136 views
How to validate reference use?
I use "reference" term here like in C++ world, not like in C# (for example). I use non-C++ syntax on purpose -- this is general question, not about this particular implementation.
Starting something ...
9
votes
4answers
1k views
Is having a generator language facility such as `yield` a good idea?
PHP, C#, Python and likely a few other languages have a yield keyword that is used to create generator functions.
In PHP: http://php.net/manual/en/language.generators.syntax.php
In Python: https://...
5
votes
2answers
176 views
How to support inheritance when designing an OO language without classes
I'm designing a programming language for a game, to be used as the main way of interacting with the game, as opposed to using other methods of control, such as the arrow keys or mouse. My plan is to ...
4
votes
1answer
128 views
Tool for validation of new code syntax in existing language
Does a programming language team have any tool to validate their new ideas about new code syntax?
As an example, let's assume the Java language team starts developing new feature, which requires new ...
8
votes
8answers
683 views
Is there a compelling reason why columns in SQL are nullable by default?
As a CS student, I've learned a decent number of programming languages over the years, most of which have had some concept of a "nullable" or "optional" type. Note that I'm not talking about null ...
8
votes
2answers
10k views
Why C allows multiple global declarations of the same variable but NOT multiple local declarations?
I noticed that if I declare a global variable multiple times the compiler does not even output a warning.
However if I declare a local variable in a function multiple times, for example, the gcc ...
2
votes
1answer
94 views
Why do the column expressions come before the table references in SELECT queries?
It strikes me as weird that the column expressions (everything between SELECT and FROM) in an SQL SELECT statement come before the table references, when the column expressions depend directly on the ...
30
votes
3answers
4k views
Why is there no static keyword in Kotlin?
Kotlin is known primarily as a drop-in replacement for Java, but it gets rid of a well-known Java construct: the static keyword. Instead, that class-level functionality is offered mainly by companion ...
11
votes
8answers
3k views
Unifying programming and database query [closed]
Consider a common tutorial for object-oriented programming languages like C++ or Java: create a simple order processing system with objects representing accounts, orders, items etc (or something more ...
2
votes
1answer
1k views
What is the motivation for Go lang syntax? [closed]
Since the Go lang is getting popular, I started to play with it. I do derive from Java language so when I saw the Go syntax it has been a bit strange to me.
sample code from go lang project site:
...
2
votes
2answers
308 views
Is implementing operator overloading with variable arity possible?
Implementing operator overloading for e.g. + (plus) isn't terribly difficult if you know it's a binary operator. One can just parse expression + expression
But what if the programmer can choose ...
