Questions involving the design and structure of programming languages.

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5
votes
7answers
565 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
254 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 ...
40
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 ...
2
votes
3answers
437 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 ...
35
votes
9answers
11k 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 ...
5
votes
2answers
796 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 ...
40
votes
5answers
6k 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 ...
4
votes
4answers
518 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
252 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 ...
4
votes
3answers
282 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 ...
2
votes
5answers
449 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 ...
8
votes
3answers
706 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
769 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 ...
22
votes
9answers
2k 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 ...
2
votes
3answers
349 views

Why are the arguments for substring functions mismatched?

In many languages, the substring function works like this: substring(startIndex, endIndex) returns the substring from startIndex until endIndex-1 (if you view startIndex and endIndex as 0-based) / ...
0
votes
2answers
157 views

Benefits of Java in education? [closed]

I hope this isn't too off-topic and/or opinion based. I'm looking for examples and reasons why Java is an acceptable language for education purposes. Here's why: I learned programming on my own in C ...
72
votes
20answers
9k 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 ...
37
votes
8answers
3k 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 ...
3
votes
6answers
285 views

Do you have to have boxing of primitives in OO language?

Is boxing of primitives required in OO languages to keep them consistent with the rest of the object system (generics etc.)? Or is it avoidable - is it possible to avoid any additional performance ...
30
votes
10answers
7k views

If null is bad, why do modern languages implement it? [closed]

I'm sure designers of languages like Java or C# knew issues related to existence of null references (see Are null references really a bad thing?). Also implementing an option type isn't really much ...
14
votes
3answers
2k views

Why null pointer instead of class cast?

In Java: int count = (Integer) null; throws a java.lang.NullPointerException. Why doesn't this throw a Class Cast Exception for ease in programmer understanding? Why was this exception chosen ...
17
votes
5answers
1k views

Why is studying an lisp interpreter in lisp so important?

I have seen many CS curriculums and learning suggestions for new programmers that call for the aspiring programmer to study a lisp interpreter that is specifically written in lisp. All these sites ...
24
votes
9answers
1k views

Why most “well-known” imperative/OO languages allow unchecked access to types that can represent a 'nothing' value?

I have been reading about the (un)convenience of having null instead of (for example) Maybe. After reading this article, I am convinced that it would be much better to use Maybe (or something ...
8
votes
12answers
2k views

Why don't more languages have the ability to compare a value to more than one other value? [closed]

Consider the following: if(a == b or c) In most languages, this would need to be written as: if(a == b or a == c) which is slightly cumbersome and repeats information. I know my above sample ...
9
votes
2answers
434 views

Why is there a new() constraint in C# but no other similar constraint?

In C# generics, we can declare a constraint for a type parameter T to have a default constructor, by saying where T : new(). However, no other kinds of constraints like this are valid - new(string) ...
2
votes
2answers
218 views

Are multi-line comments a critical facility in a modern language?

I'm trying to convince the designers of a language that multi-line comments with an arbitrary start and end are important, and should be included. Currently there is only a "comment-to-end-of-line" ...
0
votes
2answers
68 views

Storing tokens during lexing stage

I am currently implementing a lexer that breaks XML files up into tokens, I'm considering ways of passing the tokens onto a parser to create a more useful data structure out of said tokens - my ...
33
votes
3answers
1k views

Does Java development typically involve more subclassing than C#/.NET?

I've recently started looking at Android development. This has brought me back into the world of Java software development. The last time I worked with Java, I'll admit, I didn't understand OOP nearly ...
58
votes
13answers
8k 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 ...
1
vote
2answers
197 views

What's the reason of choosing PascalCasing over camelCasing or vice versa from a programming language design POV?

I like both but I notice languages that use camelCasing for members sometimes need more adjustments when you want to edit your code. For example (in Python): node.customData() vs ...
4
votes
3answers
225 views

Classes in OOP , methods and attributes memory internals [closed]

I would assume that instances of the same class would actually share their methods, and just have save different attributes in their namespace. How often do you arbitrary add methods to a single ...
41
votes
9answers
31k 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 ...
0
votes
1answer
103 views

Derivations in BNF

I get how to do a derivation of a BNF. My text books do a good job of explaining it (much better than the on-line lecture notes of many profs etc). Example below then my questions: <program> ...
1
vote
3answers
356 views

Why did the Sun engineers decided to make Java only call by value? [closed]

Is there any specific reason they decided to go with Call by value? Is it for simplicity?
6
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 ...
5
votes
5answers
2k views

why no native compiler of C# or other “productive” language? [closed]

I've been reading about D and Go and how they aim at being compiled to machine code yet be convenient (like garbage collection, no need to manipulate pointers unless needed) and I agree that there is ...
25
votes
7answers
2k views

Disadvantages of scoped-based memory management

I really like scope-based memory management (SBMM), or RAII, as it is more commonly (confusingly?) referred to by the C++ community. As far as I know, except for C++ (and C), there's no other ...
5
votes
11answers
2k views

KISS principle applied to programming language design?

KISS ("keep it simple, stupid" or "keep it simple stupid", see e.g. here) is an important principle in software development, even though it apparently originated in engineering. Citing from the ...
10
votes
4answers
1k 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: ...
11
votes
4answers
698 views

What are the problems of bringing C++-like const into a language?

I am interested in the idea of C++-like const not that particular execution (like casting away const). Take for example C# -- it lacks C++-like const, and the reason for it is the the usual -- people ...
1
vote
1answer
93 views

If a variable containing a function gave the function's return instead of a reference to the function, what would an array of functions return? [closed]

I'm creating a prototype scripting language similar to something like Javascript. In my language, every single reference to a variable is actually a function call (a getter function), whether it has ...
2
votes
3answers
731 views

What are the advantages of pass by value?

I always thought pass by value is a legacy from the early languages, because the designers had never seen anything else. But after seeing the brand new languages like Go adapting the same principle ...
5
votes
3answers
397 views

Is there a web-specific reason for the design choices behind the JavaScript language?

With the advent of "the web is the platform", JavaScript is fast becoming the most widely used programming language in the world. However, many tasks that are easy to accomplish in other modern ...
10
votes
6answers
2k views

Are there any ultra high level languages out there? [closed]

Historically a HLL is something like C, Fortran or Pascal and a VHLL is something like Ruby or Python. I am familiar with the terms 4GL, 5GL, DSL and LOP, and those who aren't should read Wikipedia ...
11
votes
10answers
2k views

Greenspun's Tenth Rule, does every large project include a Lisp interpreter? [closed]

Greenspun's tenth rule (actually the only rule) states that: Any sufficiently complicated C or Fortran program contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of ...
5
votes
2answers
187 views

Language that embraces mutable state? [closed]

There seems to be a trend towards immutable objects, and pure functional programming. While I recognize the benefits, I find it hard to apply these principles to GUI programming, for example. But I ...
1
vote
3answers
188 views

Requiring a specific order of compilaiton

When designing a compiled programming language, is it a bad idea to require a specific order of compilation of separate units, according to their dependencies? To illustrate what I mean, consider C. ...
6
votes
3answers
276 views

Clarification about Grammars , Lexers and Parsers

Background info (May Skip): I am working on a task we have been set at uni in which we have to design a grammar for a DSL we have been provided with. The grammar must be in BNF or EBNF. As well as ...
3
votes
1answer
319 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 ...