Questions involving the design and structure of programming languages.

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48
votes
9answers
36k views

Why use partial classes?

In my understanding, the partial keyword does nothing but allow a class to be split between several source files. Is there any reason to do this other than for code organization? I've seen it used for ...
1
vote
2answers
88 views

What is meant by “redundant, but not duplicative” in the Steelman language requirements?

The Steelman language requirements have this: The language shall require some redundant, but not duplicative, specifications in programs. I think I can see the underlying idea (that re-stating ...
0
votes
1answer
62 views

Is automatic conversion to collection types from non-collection variable a good idea? [closed]

Consider public void Do(string[] aBunchOfStrings) { } or public void Do(IReadOnlyList<string> aBunchOfStrings) { } Would it be a bad idea to allow the function call Do("woei"); resolve ...
2
votes
1answer
389 views

Is there a name for the 'break n' construct?

In a conversation earlier this week I was discussing certain language features, and I realized I don't have a good word / phrase to describe a particular feature. Some languages, such as PHP, have a ...
0
votes
0answers
25 views

Rationale behind CSS height with percentage value

I've been using CSS for a few years, but there are some "quirks" that I cannot quite fathom. One of them is the height property when specified with a percentage. To quote the CSS 2.1 Specification ...
5
votes
5answers
3k views

False friends? Keyword “static” in C compared to C++, C# and Java

To me, the use of the keyword static in C and languages like C# and Java are "false friends" like "to become" in English and "bekommen" in German (= "to get" in English), because they mean different ...
0
votes
0answers
51 views

Pre-Compilation Processor:

What I want to do: Parse source code, search for a beginning and closing tag of my own definition (one that does not conflict with any defined patterns in the programming language), and then replace ...
4
votes
7answers
682 views

Why are self-hosting compilers considered a rite of passage for new languages?

I've heard in a number of places now that people expect languages to use, or at least have, a self-hosting compiler in order to deserve respect. I'm curious as to why this is. A compiler seems like a ...
8
votes
4answers
406 views

Use cases for “private” interfaces?

I was wondering if there was a valid use case for being able to properly define the specific internal properties and functions of a class in a way similar to how an interface defines the public ...
40
votes
6answers
7k views

Why was C# made with “new” and “virtual+override” keywords unlike Java?

In Java there are no virtual, new, override keywords for method definition. So the working of a method is easy to understand. Cause if DerivedClass extends BaseClass and has a method with same name ...
2
votes
3answers
542 views

What could be the advantages and disadvantages of decay of Nd arrays to N-level pointers?

I have been thinking of a couple of possible extensions to the C language which I'd like to know the opinion of others about.1 This one is about multi-dimensional arrays. Imagine the following ...
38
votes
15answers
10k views

How have languages influenced CPU design? [closed]

We are often told that the hardware doesn't care what language a program is written in as it only sees the compiled binary code, however this is not the whole truth. For example, consider the humble ...
6
votes
1answer
205 views

Do any notable C extensions include integer types that are independent of machine word size

An interesting characteristic of C compared with some other languages is that many of its data types are based upon the word size of the target architecture, rather than being specified in absolute ...
11
votes
4answers
2k views

Why do all <algorithm> functions take only ranges, not containers?

There are many useful functions in <algorithm>, but all of them operate on "sequences" - pairs of iterators. E.g., if I have a container and like to run std::accumulate on it, I need to write: ...
7
votes
1answer
408 views

Why does Scala have return but not break and continue

Scala does not have break or continue, so some loop behavior takes a bit more of thinking. Ending a loop early requires tail recursion, exceptions, or scala.util.control.Breaks (which uses ...
40
votes
12answers
9k views

Should I use a parser generator or should I roll my own custom lexer and parser code?

What specific advantages and disadvantages of each way to working on a programming language grammar? Why/When should I roll my own? Why/When should I use a generator?
0
votes
2answers
281 views

What's the advantage of auto-property initializers without primary constructors?

In this chart about the features that are in or out of the next version of Roslyn (specifically, for C#), primary constructors are out, but auto-property initializers are in. The best use case I've ...
0
votes
0answers
74 views

Best way to handle language interoperability

Background In a language like F#, direct interoperability with most other .NET languages is possible. For example, it is possible to use classes written in C# directly in F#, and it is possible to ...
1
vote
2answers
193 views

Why is object-level privacy difficult to use as a paradigm, and why is it desirable?

I have heard a prominent language designer remark that no language today enforces real object privacy, and we are still unsure whether it is possible in practice to design a language that does. ...
9
votes
4answers
1k views

Why design a modern language without an exception-handling mechanism?

Many modern languages provide rich exception handling features, but Apple's Swift programming language does not provide an exception handling mechanism. Steeped in exceptions as I am, I'm having ...
5
votes
4answers
561 views

When does it make sense to compile my own language to C code first?

When designing an own programming language, when does it make sense to write a converter that takes the source code and converts it to C or C++ code so that I can use an existing compiler like gcc to ...
35
votes
12answers
4k views

Why do most programming languages have special keyword or syntax for declaring functions? [closed]

Most programming languages (both dynamically and statically typed languages) have special keyword and/or syntax that looks much different than declaring variables for declaring functions. I see ...
0
votes
3answers
140 views

What is the most robust, extensible way to represent a contract in code? [closed]

I would like to find or create a syntax to express business contracts programmatically, and I am looking for a robust, flexible, future-resistant way to do this. A client should be able to add a ...
42
votes
9answers
14k views

Why is String immutable in Java?

I couldn't understand the reason of it. I always use String class like other developers, but when I modify the value of it, I need to create new instance of String. What might be the reason of ...
1
vote
1answer
158 views

Why is Throwable initCause designed to be called only once?

I find it really odd that the initCause method of Java's Throwable class can only be called once, or even not at all (if the constructor accepting a Throwable was used). This makes exception chaining ...
1
vote
0answers
207 views

What is the logic behind the use of different arrows (-> <-) in Haskell?

I've been thinking about language design lately, and reading over some of the new things in Haskell (always a nice source of inspiration). I'm struck by the many odd uses of the left <- and right ...
4
votes
1answer
118 views

Is there a better alternative than abusing the IDisposable pattern?

Consider the following (Microsoft-sanctioned) code: <% using (Html.Form<HomeController>(action=>action.Index())) { %> <input type="text" id="search" /> <input ...
-1
votes
1answer
281 views

Are there any scenarios where the 'Dispose Pattern' shouldn't be used on an Object which contains managed and un-managed resources?

MSDN says that to properly clean up an object which contains managed and un-managed resources, you need to implement the 'Dispose Pattern'. Given that the class implements the IDisposable interface, ...
77
votes
20answers
11k views

Are null references really a bad thing?

I've heard it said that the inclusion of null references in programming languages is the "billion dollar mistake". But why? Sure, they can cause NullReferenceExceptions, but so what? Any element of ...
4
votes
4answers
708 views

How does Python compile some its code in C?

I read that some constructs of Python are more efficient because they are compiled in C. https://wiki.python.org/moin/PythonSpeed/PerformanceTips Some of the examples used were map() and filter(). I ...
2
votes
1answer
227 views

How do you make decorators as powerful as macros?

Quick background: I am designing a Pythonic language that I want to be as powerful as Lisp while remaining easy to use. And by "powerful", I mean "flexible and expressive". I've just been introduced ...
37
votes
22answers
3k views

Has whitespace in identifiers ever been idiomatic? [closed]

C# style suggests using CamelCase in identifiers to delimit words. Lisp tradition suggests using-dashes-instead. Has there ever existed a programming language where using spaces in identifiers was ...
1
vote
3answers
78 views

Property-level value transformation for indirect object casting

Does any programming language exist to support the explicit, property-level object copy? For example, assume this code: public class Student { public string Name { get; set; } public ...
43
votes
9answers
4k views

Why don't languages include implication as a logical operator?

It might be a strange question, but why there is no implication as a logical operator in many languages (Java, C, C++, Python Haskell - although as last one have user defined operators its trivial to ...
61
votes
14answers
12k views

Why is 0 false?

This question may sound dumb, but why does 0 evaluates to false and any other [integer] value to true is most of programming languages? String comparison Since the question seems a little bit too ...
8
votes
3answers
987 views

Is duplicate syntax for defining named functions a bad language design decision?

I am modelling a programming language for fun, and the syntax is heavily influenced by Scala - specifically function definitions. I have encountered a design problem because my language does not ...
5
votes
5answers
1k views

What negative consequences can arise from this language design rule?

Clarification: the rule is meant to prevent accessing variables that are not declared yet. Clarification 2: the rule mandates that the compiler follows calls to functions which are defined in the ...
4
votes
5answers
905 views

Does this kind of programming language exist?

I'm thinking about creating my own pet programming language, and I have been wondering if similar language already exists. The basic idea is that the language itself would be dynamically typed with ...
6
votes
7answers
742 views

Why isn't there a next operation on enums?

In most popular programming languages like Java and C# there is a way to define enums, which are essentially datatypes with a fixed set of values, e.g. DayOfWeek. The problem is, given a value, e.g. ...
0
votes
2answers
1k views

Why doesn't Ruby have implicit conversion of Fixnum into String?

Ruby normally makes things easy. However, it doesn't allow implicitely converting a number to a string: 2.0.0p247 :010 > "a"+1 TypeError: no implicit conversion of Fixnum into String Why is this ...
42
votes
7answers
3k views

Why is the finalize method included in Java?

According to this post, we should never rely on the finalize method to be called. So why did Java include it in the programming language at all? It seems like a terrible decision to include in any ...
4
votes
3answers
524 views

Functional programming strategies in imperative languages

I've been convinced for awhile now that some strategies in functional programming are better suited to a number of computations (i.e immutability of data structures). However, due to the popularity of ...
5
votes
4answers
601 views

Why do arrays in Java not override equals()?

I was working with a HashSet the other day, which has this written in the spec: [add()] adds the specified element e to this set if this set contains no element e2 such that (e==null ? e2==null : ...
1
vote
2answers
285 views

Go-like interfaces + multi-methods make sense?

Thinking about the design of a potential new language, I wonder how related are the concepts of built a OO similar to GO interfaces and multi-methods (I get this from ...
3
votes
2answers
292 views

Comparison of languages by usage type? [closed]

Does anyone know of a good place to go find comparisons of programming languages by the intended platform/usage? Basically, what I want to know, is of the more popular languages, which ones are meant ...
3
votes
5answers
570 views

Should sanity be a property of a programmer or a program? [closed]

I design and implement languages, that can range from object notations to markup languages. In many cases I have considered restrictions in favor of sanity (common knowledge), like in the case of ...
7
votes
3answers
814 views

What is a real-world use case of using a Chomsky Type-I (context-sensitive) grammar

I have been having some fun lately exploring the development of language parsers in the context of how they fit into the Chomsky Hierarchy. What is a good real-world (ie not theoretical) example of a ...
18
votes
13answers
1k views

Should data structures be integrated into the language (as in Python) or be provided in the standard library (as in Java)?

In Python, and most likely many other programming languages, common data structures can be found as an integrated part of the core language with their own dedicated syntax. If we put LISP's integrated ...
5
votes
4answers
854 views

Is there a math theory or a model behind programming languages design

I'm trying to understand if a programming languages design is built on some a theoretical model. I came across few links that was describing Programming Language Theory, Lambda Calculus, Formal ...
21
votes
9answers
3k views

Are there any programming languages that follow a minimalist development approach?

I find it that when languages are considered the same as commercial software, there is always a constant need to add new features to justify new releases. Can there be or are there languages where ...