a type system is a collection of rules that assign a property called a type to the various constructs—such as variables, expressions, functions or modules— that a computer program is composed of.

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Would it make sense to use objects (instead of primitive types) for everything in C++?

During a recent project I've been working on, I've had to use a lot of functions that kind of look like this: static bool getGPS(double plane_latitude, double plane_longitude, double plane_altitude, ...
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Is changing the type of a variable partway through a procedure in a dynamically typed language bad style?

In Python (and occasionally PHP) where variables do not have fixed types, I'll frequently perform 'type transformations' on a variable part-way through my code's logic. I'm not (necessarily) talking ...
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4answers
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Why does Java not do type inference?

I have always wondered why Java does not do type inference given that the language is what it is, and its VM is very mature. Google's Go is an example of a language with excellent type inference and ...
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Type systems: nominal vs. structural, explicit vs. implicit

I'm a bit confused about the difference between nominal and structural type systems. Can someone please explain how they differ? From what I understand: Nominal: Type compatibility is based on type ...
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Motivation and pitfalls (?) of the auto keyword in C++11

I was recently wondering why the keyword auto was chosen in C++11 to mark a variable whose type must be inferred by the compiler, like in auto x = 1; Since var seems more common in other ...
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1answer
427 views

What does “polyadic” mean in the context of functional programming and type systems?

And how does it (or does not) correspond to "polymorphic"? Occasionally I see this notion like in: Implement and represent polyadic operations. I checked Wiktionary but it only gives a general ...
15
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1answer
930 views

Why doesn't Haskell have type-level lambda abstractions?

Are there some theoretical reasons for that (like that the type checking or type inference would become undecidable), or practical reasons (too difficult to implement properly)? Currently, we can ...
21
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2answers
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Type inference in Java 8

Is the introduction of the new lambda notation (see e.g. this article) in Java 8 going to require some kind of type inference? If so, how will the new type system impact the Java language as a whole? ...
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Generics and Type-erasure

Generics in Java are implemented using type erasure. The JLS says that the inspiration was backward compatibility. Where as on the other hand C# generics are reifiable. Theoretically what are the ...
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444 views

Why do generics in Scala have erased types, and are not reifiable?

Why do generics in Scala have erased types, and are not reifiable? Is it due to lack of support from the JVM or for compatibility with Java libraries? What are the advantages in general of having ...
8
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5answers
671 views

Are there programming languages that allow you to do set arithmetic on types?

Out of curiosity, are there languages that allow you to do set arithmetic on types to create new types? Something like: interface A { void a(); void b(); } interface B { void b(); void ...
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What can Haskell's type system do that Java's can't and vice versa?

I was talking to a friend about the differences between the type systems of Haskell and Java. He asked me what Haskell's could do that Java's couldn't, and I realized that I didn't know. After ...
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Duck checker in Python: does one exist?

Python uses duck-typing, rather than static type checking. But many of the same concerns ultimately apply: does an object have the desired methods and attributes? Do those attributes have valid, ...
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7answers
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Which statically typed languages support intersection types for function return values?

Initial note: This question got closed after several edits because I lacked the proper terminology to state accurately what I was looking for. Sam Tobin-Hochstadt then posted a comment which ...
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3answers
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Is there a difference between casting and converting types in imperative programming languages?

The question came up in a discussion at StackOverflow. Is there a clean distinction between the two concepts cast and convert (concerning the type of an object), or are these two words describing ...
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2answers
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Nulls in every type and checked exceptions in Java?

I know that null being added to every type in Java is a source of much frustration regarding the language's type system. At the same time I generally hear complaining about checked exceptions - that ...
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792 views

How do existential types differ from interfaces?

Given the existential type T = ∃X.{op₁:X, op₂:X→boolean} and this generic Java interface: interface T<X> { X op₁(); boolean op₂(X something); } What are the fundamental differences ...
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9answers
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Mission critical embedded language [closed]

Maybe the question sounds a bit strange, so I'll explain a the background a little bit. Currently I'm working on a project at y university, which will be a complete on-board software for an ...
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2answers
541 views

Values, types, kinds, and…?

We all know what a value is. A type is the type of a value. A kind is (loosely) the type of a type. A type constructs a value; a kind constructs a type. So what is the type of a kind, a thing that ...
12
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(Dis-)advantages of structural typing

I’ve just watched this talk by Daniel Spiewak where he talks about the advantages of structural typing as compared to Scala’s ans Java’s nominal typing. One example for this difference would be the ...
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6answers
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Is hungarian notation a workaround for languages with insufficiently-expressive (i.e. Haskell-style) static typing?

Edit To be clear, I'm not talking about annotation variable names with the data type, but rather with information about the meaning of the variable in the context of the program. For example, a ...
0
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4answers
452 views

Teaching programmer looking for a simple statically and weakly typed language [closed]

I'm trying to illustrate the differences between the four different type systems -- static vs. dynamic typing and weak vs. strong typing. Dynamic + weak = JavaScript Dynaimc + strong = Python ...
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656 views

About languages strongly typed with late binding, do they make sense?

I never learnt anything about VB6 (and I dont want to) but I wanted to search for bad things in computer software, so my first though was VB6. So for example, VB6 was strongly typed with late ...
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1answer
576 views

C# type system and dynamic type

I'm writing a paper about the C# (and Go) type system with focus on the dynamic aspect. Does anybody have suggestions for papers/literature? The things I found don't go much into detail. I would ...
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1answer
381 views

static languages or dynamic languages? [closed]

What is the exact border between the static and dynamic languages? I mean I am told the following parameters are the deciding factors: Compilation or interpretation Typing Runtime generation Dynamic ...
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10answers
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Why are inheritance and polymorphism so widely used?

The more I learn about different programming paradigms, such as functional programming, the more I begin to question the wisdom of OOP concepts like inheritance and polymorphism. I first learned ...
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24answers
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Interesting or unique types in programming languages? [closed]

We have all seen integer, floating point, string, and the occasional decimal type. What are some of the most strange or unique or useful types you have encountered, useful or not?
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What arguments are there in favor of weak typing?

This came up in a discussion with a friend, and I found myself hard-pressed to think up an any good arguments. What benefits do weak typing confer?
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3answers
368 views

What are some reasonable stylistic limits on type inference?

C++0x adds pretty darn comprehensive type inference support. I'm sorely tempted to use it everywhere possible to avoid undue repetition, but I'm wondering if removing explicit type information all ...
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4answers
231 views

objects, classes, types

How does an object oriented programmer understand the word "type"? I'm not aware of there being a type theory for object oriented programming because whenever someone mentions type theory it is always ...
29
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7answers
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Is Haskell's type system an obstacle to understanding functional programming? [closed]

I'm studying Haskell for the purpose of understanding functional programming, with the expectation that I'll apply the insight that I gain in other languages (Groovy, Python, JavaScript mainly.) I ...
20
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9answers
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Type Casting variables in PHP: Is there a practical example?

PHP, as most of us know, has weak typing. For those who don't, PHP.net says: PHP does not require (or support) explicit type definition in variable declaration; a variable's type is determined ...
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6answers
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Dynamically vs Statically typed languages studies

Do there exist studies done on the effectiveness of statically vs dynamically typed languages? In particular: Measurements of programmer productivity Defect Rate Also including the effects of ...
28
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Do dynamic typed languages deserve all the criticism? [closed]

I have read a few articles on Internet about programming language choice in the enterprise. Recently many dynamic typed languages have been popular, i.e. Ruby, Python, PHP and Erlang. But many ...