Since you’ve tagged this question with sympy, I will give such an example. From the documentation: http://docs.sympy.org/latest/modules/plotting.html. from sympy import var, plot_implicit var(‘x y’) plot_implicit(x*y**3 – y*x**3)
try { Intent intent = new Intent(“com.google.zxing.client.android.SCAN”); intent.putExtra(“SCAN_MODE”, “QR_CODE_MODE”); // “PRODUCT_MODE for bar codes startActivityForResult(intent, 0); } catch (Exception e) { Uri marketUri = Uri.parse(“market://details?id=com.google.zxing.client.android”); Intent marketIntent = new Intent(Intent.ACTION_VIEW,marketUri); startActivity(marketIntent); } and in onActivityResult(): @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); if (requestCode == 0) { if (resultCode … Read more
I wrote my own answer in the form of a blog post revisiting implicits without import tax. Update: Furthermore, the comments from Martin Odersky in the above post revealed that the Scala 2.9.1’s behavior of LocalIntFoo winning over ImportedIntFoo is in fact a bug. See implicit parameter precedence again. 1) implicits visible to current invocation … Read more
There are two distinct features here. First, request isn’t really an argument in a method invocation. It’s the argument of an anonymous function. The anonymous function itself is the argument of the method invocation. Second, declaring an implicit argument in an anonymous function have the convenience of saving you from “forcing” a val into a … Read more
Resharper is primarily concerned with helping you refactor code, and the var keyword generally makes refactoring easier. For example, if the return values of any of those functions ever change to a compatibile type, you don’t have to change any of this code. It’s therefore now a little easier to refactor your tabCaseNotes type, for … Read more
There is a solution. Consider the following: public sealed class AccountStatus { public static readonly AccountStatus Open = new AccountStatus(1); public static readonly AccountStatus Closed = new AccountStatus(2); public static readonly SortedList<byte, AccountStatus> Values = new SortedList<byte, AccountStatus>(); private readonly byte Value; private AccountStatus(byte value) { this.Value = value; Values.Add(value, this); } public static implicit … Read more
I get asked questions like this all the time. Basically the question boils down to “when a fact about a declared member can be deduced by the compiler should the explicit declaration of that fact be (1) required, (2) optional, or (3) forbidden?” There’s no one easy answer. Each one has to be taken on … Read more
It’s very common in C to write this void f(T* ptr) { if (ptr) { // ptr is not NULL } } You should make a const char* constructor.
You can debug implicits at compile time: switch on compiler flag -Xlog-implicits try to resolve implicits manually (maybe specifying type parameters as well) and see compile errors implicitly[…](…manually…) use scala.reflect println(reify { implicitly[…] }.tree) (or switch on compiler flag -Xprint:typer) in order to see how implicits are resolved use IDE functionality to show implicits using … Read more
One use case, as requested… Imagine you have a list of things, could be integers, floating point numbers, matrices, strings, waveforms, etc. Given this list, you want to add the contents. One way to do this would be to have some Addable trait that must be inherited by every single type that can be added … Read more