There is not. Go does *not* provide [a *logical*](http://golang.org/ref/spec#Logical_operators) exclusive-OR operator (i.e. XOR over booleans) and [the *bitwise* XOR operator](http://golang.org/ref/spec#Arithmetic_operators) applies only to integers.

However, [an exclusive-OR](http://en.wikipedia.org/wiki/Exclusive_or) can be rewritten in terms of other logical operators. When re-evaluation of the expressions (X and Y) is ignored,

    X xor Y -&gt; (X || Y) &amp;&amp; !(X &amp;&amp; Y)

Or, more trivially as Jsor pointed out,

    X xor Y &lt;-&gt; X != Y

With booleans an xor is simply:

    if boolA != boolB {
    
    }

In this context `not equal to` performs the same function as `xor`: the statement can only be true if one of the booleans is true and one is false.

I installed some package via `pip install something`. I want to edit the source code for the package `something`. Where is it (on ubuntu 12.04) and how do I make it reload each time I edit the source code and run it?

Currently I am editing the source code, and then running python setup.py again and again, which turns out to be quite a hassle.

Python: how to edit an installed package?

I have a string that I called Blob() on:
    
    var mystring = &quot;Hello World!&quot;;
    var myblob = new Blob([mystring], {
        type: &#39;text/plain&#39;
    });
    mystring = &quot;&quot;;

How do I get the string back out? 

    function getBlobData(blob) {
        // Not sure what code to put here
    }
    alert(getBlobData(myblob)); // should alert &quot;Hello World!&quot;

Javascript - I created a blob from a string, how do I get the string back out?

Is there no XOR operator for booleans in golang?

I was trying to do something like `b1^b2` but it said it wasn&#39;t defined for booleans.

Is there no XOR operator for booleans in golang?

<p>Is there no XOR operator for booleans in golang?</p>
<p>I was trying to do something like <code>b1^b2</code> but it said it wasn't defined for booleans.</p>


Given a struct:

    type MyStruct struct {
        A int
        B int
    }

and a string with the struct&#39;s name

    a := &quot;MyStruct&quot;

or

    a := &quot;mypkg.MyStruct&quot;


How do I create an instance of my struct from the string name rather than the struct? The idea is that I would create an application with all of the structures linked into the binary but create the runtime instances from the strings. (sort of a meta-meta)

is there a way to create an instance of a struct from a string?

In an error condition, I tried to return `nil`, which throws the error:

    cannot use nil as type time.Time in return argument

What is the `zero` value for `time.Time`?

What is the `zero` value for time.Time in Go?

I&#39;m trying to copy the contents of a map ( ``amap`` ) inside another one (``aSuperMap``) and then clear  ``amap`` so that it can take  new values on the next iteration/loop. 
  The issue is that you can&#39;t clear the map [without to clear its reference][1] in the supermap as well.
 Here is some pseudo code.

    for something := range fruits{
            aMap := make(map[string]aStruct)
            aSuperMap := make(map[string]map[string]aStruct)
            
            for x := range something{
            	aMap[x] = aData
            	aSuperMap[y] = aMap
                delete(aMap, x)
        }
    //save aSuperMap
      saveASuperMap(something)
    
    }

  I&#39;ve also tried some dynamic stuff but obviously it throws an error (cannot assign to nil)

	aSuperMap[y][x] = aData

The question is how can I create an associative map ? In PHP I simply use  aSuperMap[y][x] = aData. It seems that golang doesn&#39;t have any obvious method. If I delete  ``delete(aMap, x)`` its reference from the super map is deleted as well. If I don&#39;t delete it the supermap ends up with duplicate data. Basically on each loop it gets ``aMap`` with the new value plus all the old values. 

  [1]: https://stackoverflow.com/a/23058707/3257971

How to copy a map?

I&#39;m new to interfaces and trying to do SOAP request by [github][1]  


  [1]: https://github.com/webconnex/xmlutil/blob/master/xmlutil.go

I don&#39;t understand the meaning of 

    Msg interface{}

in this code:  

    type Envelope struct {
    	Body `xml:&quot;soap:&quot;`
    }
    
    type Body struct {
    	Msg interface{}
    }

I&#39;ve observed the same syntax in

    fmt.Println

but don&#39;t understand what&#39;s being achieved by 

    interface{}

What&#39;s the meaning of interface{}?

I&#39;m running a test in Go with a statement to print something (i.e. for debugging of tests) but it&#39;s not printing anything.

    func TestPrintSomething(t *testing.T) {
    	fmt.Println(&quot;Say hi&quot;)
    }

When I run go test on this file, this is the output:

    ok  	command-line-arguments	0.004s

The only way to really get it to print, as far as I know, is to print it via t.Error(), like so: 

    func TestPrintSomethingAgain(t *testing.T) {
    	t.Error(&quot;Say hi&quot;)
    }

Which outputs this:

    Say hi
    --- FAIL: TestPrintSomethingAgain (0.00 seconds)
    	foo_test.go:35: Say hi
    FAIL
    FAIL	command-line-arguments	0.003s
    gom:  exit status 1


I&#39;ve Googled and looked through the manual but didn&#39;t find anything.

How do you print in a Go test using the &quot;testing&quot; package?

I don&#39;t understand why JavaScript works this way.

    console.log(&quot;1&quot; + 1);
    console.log(&quot;1&quot; - 1);

The first line prints 11, and the second prints 0.
Why does JavaScript handle the first as a String and the second as a number?

Why does JavaScript handle the plus and minus operators between strings and numbers differently?

I know `@` is for decorators, but what is `@=` for in Python? Is it just reservation for some future idea?

This is just one of my many questions while reading `tokenizer.py`.

What is the &#39;@=&#39; symbol for in Python?

With C# 6.0 in the VS2015 preview we have a new operator, **`?.`**, which can be used like this:

&lt;!-- language: lang-cs --&gt;

    public class A {
       string PropertyOfA { get; set; }
    }

    ...

    var a = new A();
    var foo = &quot;bar&quot;;
    if(a?.PropertyOfA != foo) {
       //somecode
    }

What exactly does it do?

What does question mark and dot operator ?. mean in C# 6.0?

PHP 7, which will come out in November this year will introduce the Spaceship (&lt;=&gt;) operator. What is it and how does it work?

&lt;sub&gt;This question already has [an answer][1] in our general reference question about PHP operators.&lt;/sub&gt;


  [1]: https://stackoverflow.com/questions/3737139/reference-what-does-this-symbol-mean-in-php/31298778#31298778

What is &lt;=&gt; (the &#39;Spaceship&#39; Operator) in PHP 7?

After reading [this answer][2] about undefined behavior and sequence points, I wrote a small program:

    #include &lt;stdio.h&gt;

    int main(void) {
      int i = 5;
      i = (i, ++i, 1) + 1;
      printf(&quot;%d\n&quot;, i);
      return 0;
    }

The output is `2`. Oh God, I didn&#39;t see the decrement coming! What is happening here?

Also, while compiling the above code, I got a warning saying:

&gt; px.c:5:8: warning: left-hand operand of comma expression has no effect&lt;br&gt;
&gt;
&gt;       [-Wunused-value]   i = (i, ++i, 1) + 1;
&gt;                             ^

Why? But probably it will be automatically answered by the answer of my first question.

  [1]: https://stackoverflow.com/questions/30605380/bash-usr-bin-hydra-pmi-proxy-no-such-file-or-directory
  [2]: https://stackoverflow.com/a/4176333/2411320


What does i = (i, ++i, 1) + 1; do?

I would like the element-wise logical OR operator. I know &quot;or&quot; itself is not what I am looking for.

I am aware that AND corresponds to `&amp;` and NOT, `~`. But what about OR? 

  [1]: https://stackoverflow.com/questions/21415661/logic-operator-for-boolean-indexing-in-pandas &quot;here&quot;
  [2]: https://stackoverflow.com/questions/15998188/how-can-i-obtain-the-element-wise-logical-not-of-a-pandas-series

Element-wise logical OR in Pandas

The short circuiting behaviour of the operators `&amp;&amp;` and `||` is an amazing tool for programmers.

But why do they lose this behaviour when overloaded? I understand that operators are merely syntactic sugar for functions but the operators for `bool` have this behaviour, why should it be restricted to this single type? Is there any technical reasoning behind this?

Is there actually a reason why overloaded &amp;&amp; and || don&#39;t short circuit?

I read the C# Language Specification on the _Conditional logical operators_ `||` and `&amp;&amp;`, also known as the short-circuiting logical operators. To me it seemed unclear if these existed for nullable booleans, i.e. the operand type `Nullable&lt;bool&gt;` (also written `bool?`), so I tried it with non-dynamic typing:

    bool a = true;
    bool? b = null;
    bool? xxxx = b || a;  // compile-time error, || can&#39;t be applied to these types

That seemed to settle the question (I could not understand the specification clearly, but assuming the implementation of the Visual C# compiler was correct, now I knew).

However, I wanted to try with `dynamic` binding as well. So I tried this instead:

    static class Program
    {
      static dynamic A
      {
        get
        {
          Console.WriteLine(&quot;&#39;A&#39; evaluated&quot;);
          return true;
        }
      }
      static dynamic B
      {
        get
        {
          Console.WriteLine(&quot;&#39;B&#39; evaluated&quot;);
          return null;
        }
      }
    
      static void Main()
      {
        dynamic x = A | B;
        Console.WriteLine((object)x);
        dynamic y = A &amp; B;
        Console.WriteLine((object)y);

        dynamic xx = A || B;
        Console.WriteLine((object)xx);
        dynamic yy = A &amp;&amp; B;
        Console.WriteLine((object)yy);
      }
    }

The surprising result is that this runs without exception.

Well, `x` and `y` are not surprising, their declarations lead to both properties being retrieved, and the resulting values are as expected, `x` is `true` and `y` is `null`.

But the evaluation for `xx` of `A || B` lead to no binding-time exception, and only the property `A` was read, not `B`. Why does this happen? As you can tell, we could change the `B` getter to return a crazy object, like `&quot;Hello world&quot;`, and `xx` would still evaluate to `true` without binding-problems...

Evaluating `A &amp;&amp; B` (for `yy`) also leads to no binding-time error. And here both properties are retrieved, of course. Why is this allowed by the run-time binder? If the returned object from `B` is changed to a &quot;bad&quot; object (like a `string`), a binding exception does occur.

___Is this correct behavior?___ (How can you infer that from the spec?)

If you try `B` as first operand, both `B || A` and `B &amp;&amp; A` give runtime binder exception (`B | A` and `B &amp; A` work fine as everything is normal with non-short-circuiting operators `|` and `&amp;`).

(Tried with C# compiler of Visual Studio 2013, and runtime version .NET 4.5.2.)

Do short-circuiting operators || and &amp;&amp; exist for nullable booleans? The RuntimeBinder sometimes thinks so

The logical expression `( a &amp;&amp; b )` *(both `a` and `b` have boolean values)* can be written like `!(!a || !b)`, for example. Doesn&#39;t this mean that `&amp;&amp;` is &quot;unneccesary&quot;? Does this mean that *all* logical expressions can be made only using `||` and `!`? 

Are || and ! operators sufficient to make every possible logical expression?

Is it possible in Handlebars to check if a string is equal to another value without registering a helper? I can&#39;t seem to find anything relevant to this in the Handlebars reference.

For example:

    {{#if sampleString == &quot;This is a string&quot;}}
    ...do something
    {{/if}}

Content Type	Original Author	Original Content on Stackoverflow
Question	Charlie Parker	View Question on Stackoverflow
Solution 1 - Go	user2864740	View Answer on Stackoverflow
Solution 2 - Go	Alasdair	View Answer on Stackoverflow

Is there no XOR operator for booleans in golang?

Go Problem Overview

Go Solutions

Solution 1 - Go

Solution 2 - Go

Javascript - I created a blob from a string, how do I get the string back out?

Python: how to edit an installed package?

Attributions