What are the practical limitations of a non-turing complete language like Coq?

First, I assume you’ve already heard of the Church-Turing thesis, which states that anything we call “computation” is something that can be done with a Turing machine (or any of the many other equivalent models). So a Turing-complete language is one in which any computation can be expressed. Conversely, a Turing-incomplete language is one in … Read more

What is a “real” programming language? [closed]

First we need to know what a programming language is. At its minimum, a programming language is something that is read by the computer and instructs it to perform certain operations. Many people would also expect a general purpose programming language to be Turing complete. However there could be situations where a domain-specific language isn’t … Read more

Which programming languages can be used to develop in Android? [duplicate]

At launch, Java was the only officially supported programming language for building distributable third-party Android software. Android Native Development Kit (Android NDK) which will allow developers to build Android software components with C and C++. In addition to delivering support for native code, Google is also extending Android to support popular dynamic scripting languages. Earlier … Read more

What is a ‘thunk’, as used in Scheme or in general?

It is really simple. When you have some computation, like adding 3 to 5, in your program, then creating a thunk of it means not to calculate it directly, but instead create a function with zero arguments that will calculate it when the actual value is needed. (let ((foo (+ 3 5))) ; the calculation … Read more

Start Activity inside onReceive BroadcastReceiver

You have context passed as parameter to onRecieve() method, so just use: @Override public void onReceive(Context context, Intent intent) { //start activity Intent i = new Intent(); i.setClassName(“com.test”, “com.test.MainActivity”); i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); context.startActivity(i); } It works, of course you have to change package and activity class name to your own.

What is so special about Smalltalk? [closed]

Smalltalk was one of the earliest object-oriented (OO) languages (with others like Simula and Eiffel) and can be said to be extremely “pure” in an OO sense: Everything is an object and objects are only communicated with via the sending of messages No primitives (no ints, booleans etc) No control structures (no for, while, if … Read more

What does composability mean in context of functional programming?

Marcelo Cantos gave a pretty good explanation, but I think it can be made slightly more precise. A type of thing is composable when several instances can be combined in a certain way to produce the same type of thing. Control structure composability. Languages like C make a distinction between expressions, which can be composed … Read more

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