type `:load /path/to/file` in Scala REPL.

You can get complete list of available commands by typing `:help`

    

On occasions, `:paste` might be your better friend (than `:load`). Here is an example on how to use *:paste*.

    scala&gt; :paste
    // Entering paste mode (ctrl-D to finish)
    
    if (true)
      print(&quot;that was true&quot;)
    else
      print(&quot;false&quot;)
    
    [Ctrl-D]
    
    // Exiting paste mode, now interpreting.

    that was true

One can also use `:paste` to load a file using following command `:paste [path]`

    scala&gt; :paste ~/Desktop/repl_seeder.scala
    Pasting file ~/Desktop/repl_seeder.scala...
    defined object test1
    
    scala&gt; test1.main(Str)
    my first scala program

Just reminder, put the complete path. I found problem in Linux by doing like this:

&gt; :load ~/fileName.scala

to get rid of error &quot;That file does not exist&quot; I did

&gt; :load /complete/path/fileName.scala



I know that multiple parameters can be passed to `COALESCE`, but  when you want to to 
check just one expression to see if it doesn&#39;t exist, do you use a default or is it a better practice to use `ISNULL` instead? 

Is there any performance gain between the two?


Using ISNULL vs using COALESCE for checking a specific condition?

Good day. 

The one thing I now hate about Haskell is quantity of packages for working with string.

First I used native Haskell `[Char]` strings, but when I tried to start using hackage libraries then completely lost in endless conversions. Every package seem to use different strings implementation, some adopts their own handmade thing.

Next I rewrote my code with `Data.Text` strings and `OverloadedStrings` extension, I chose `Text` because it has a wider set of functions, but it seems many projects prefer `ByteString`.&lt;br /&gt;
Someone could give short reasoning why to use one or other?

PS: btw how to convert from `Text` to `ByteString`?

&gt; Couldn&#39;t match expected type
&gt; *Data.ByteString.Lazy.Internal.ByteString*
&gt;            against inferred type *Text*
&gt;       Expected type: IO Data.ByteString.Lazy.Internal.ByteString
&gt;       Inferred type: IO Text

I tried `encodeUtf8` from `Data.Text.Encoding`, but no luck:

&gt; Couldn&#39;t match expected type
&gt; *Data.ByteString.Lazy.Internal.ByteString*
&gt;            against inferred type *Data.ByteString.Internal.ByteString*


**UPD:**

Thanks for responses, that *Chunks goodness looks like way to go, but I somewhat shocked with result, my original function looked like this:

    htmlToItems :: Text -&gt; [Item]
    htmlToItems =
        getItems . parseTags . convertFuzzy Discard &quot;CP1251&quot; &quot;UTF8&quot;


And now became:

    htmlToItems :: Text -&gt; [Item]
    htmlToItems =
        getItems . parseTags . fromLazyBS . convertFuzzy Discard &quot;CP1251&quot; &quot;UTF8&quot; . toLazyBS
        where
          toLazyBS t = fromChunks [encodeUtf8 t]
          fromLazyBS t = decodeUtf8 $ intercalate &quot;&quot; $ toChunks t


And yes, this function is not working because its wrong, if we supply `Text` to it, then we&#39;re confident this text is properly encoded and ready to use and converting it is stupid thing to do, but such a verbose conversion still has to take place somewhere outside `htmltoItems`.

Text or Bytestring

I have some Scala functions defined in a file, not in a class, and I would like to use them in the Scala interpreter. I know I can say `scala filename.scala` to simply run the file and exit the interpreter, but I would like to run the file and then stay in the interpreter so I can do some testing. Can anyone tell me how to simply load a file into the interpreter so I can use the functions defined within it?

Load Scala file into interpreter to use functions?

<p>I have some Scala functions defined in a file, not in a class, and I would like to use them in the Scala interpreter. I know I can say <code>scala filename.scala</code> to simply run the file and exit the interpreter, but I would like to run the file and then stay in the interpreter so I can do some testing. Can anyone tell me how to simply load a file into the interpreter so I can use the functions defined within it?</p>


Given the following constructs for defining a function in Scala, can you explain what the difference is, and what the implications will be?

    def foo = {}

vs.

    def foo() = {}


*Update*

Thanks for the quick responses.  These are great.  The only question that remains for me is:

If I omit the parenthesis, is there still a way to pass the function around?  This is what I get in the repl:

    scala&gt; def foo = {}
    foo: Unit
    
    scala&gt; def baz() = {}
    baz: ()Unit
    
    scala&gt; def test(arg: () =&gt; Unit) = { arg }
    test: (arg: () =&gt; Unit)() =&gt; Unit
    
    scala&gt; test(foo)
    &lt;console&gt;:10: error: type mismatch;
     found   : Unit
     required: () =&gt; Unit
                  test(foo)
                       ^
    
    scala&gt; test(baz)
    res1: () =&gt; Unit = &lt;function0&gt;
    
----------

***Update 2012-09-14***

Here are some similar questions I noticed:

 1. https://stackoverflow.com/q/7600910/293064
 2. https://stackoverflow.com/q/6939908/293064

What is the difference between def foo = {} and def foo() = {} in Scala?

I have looked at [this question][1] but still don&#39;t understand the difference between Iterable and Traversable traits. Can someone explain ?


  [1]: https://stackoverflow.com/questions/2602379/in-scala-2-8-collections-why-was-the-traversable-type-added-above-iterable

Scala: What is the difference between Traversable and Iterable traits in Scala collections?

I&#39;m trying to unit-test some Scala that is very collection-heavy. These collections are returned as `Iterable[T]`, so I am interested in the *contents* of the collection, even if the underlying types differ. This is actually two related problems:

1. How do I assert that two **ordered** collections contain the same sequence of elements?
1. How do I assert that two **unordered** collections contain the same set of elements?

In summary, I&#39;m looking the Scala-equivalent of NUnit&#39;s `CollectionAssert.AreEqual` (ordered) and `CollectionAssert.AreEquivalent` (unordered) in ScalaTest:

    Set(1, 2) should equal (List(1, 2))          // ordered, pass
    Iterable(2, 1) should equal (Iterable(1, 2)) // unordered, pass

Comparing collection contents with ScalaTest

Coming back to Scala after a spell writing Haskell, I&#39;ve started using the type keyword to make my class definitions a bit more readable, eg:

    type RestfulParams = Map[String, String]
    def canonicalize(params: RestfulParams): String = { ... }

The trouble I&#39;ve run into is that these type definitions need to live inside a class or object - they&#39;re not &quot;first class citizens&quot; like they are in Haskell. If I try to define a type outside of a class or object, I get a compiler `expected class or object definition`.

My problem then is how to use these types across multiple classes and objects in a package? What I&#39;ve done now seems quite ugly:

    object RestfulTypes { type RestfulParams = Map[String, String] etc }

And then in another class file:

    import utils.{RestfulTypes =&gt; RT}
    def get(resource: String, params: RT.RestfulParams): String = { ... }

Is there a nicer way of doing this - and incidentally do the Scala gurus think it&#39;s a good thing or a bad thing that types can only be defined inside classes/objects?

Scala type keyword: how best to use it across multiple classes

How to split a List of elements into lists with at most N items?

ex: Given a list with 7 elements, create groups of 4, leaving the last group possibly with less elements.

    split(List(1,2,3,4,5,6,&quot;seven&quot;),4)
        
    =&gt; List(List(1,2,3,4), List(5,6,&quot;seven&quot;))



Split list into multiple lists with fixed number of elements

Cannot figure out, where to change EOF in PyCharm.
My scripts, started with:

    #!/usr/bin/python
    # -*- coding: utf-8 -*-

Outputs something like this, when I try to run it like executable (chmode +x):

&gt; -bash: ./main.py: /usr/bin/python^M: bad interpreter: No such file or directory

What to do and how to be?

PyCharm. /usr/bin/python^M: bad interpreter

How can i measure the time taken by a method and the individual statements in that method in Ruby. If you see the below method i want to measure the total time taken by the method and the time taken for database access and redis access. I do not want to write Benchmark.measure before every statement. Does the ruby interpreter gives us any hooks for doing this ?

    def foo
    # code to access database
    # code to access redis. 
    end

Measure and Benchmark Time for Ruby Methods

I created this function in Python 2.7 with `ipython`:

    def _(v):
        return v

later if I call `_(somevalue)`, I get `_ = somevalue`.

    in[3]: _(3)
    out[3]: 3
    in[4]: print _
    out[4]: 3

The function has disappeared! If I call `_(4)` I get:

```none
TypeError: &#39;int&#39; object is not callable
```

Why? What&#39;s wrong with this function?


Assigning a value to single underscore _ in Python/IPython interpreter

I&#39;ve downloaded **Algebird** and I want to try out few things in the **Scala interpreter** using this library. How do I achieve this? 

How to use third party libraries with Scala REPL?

During a reactJS session that I was attending, the presenter used a term transpiler for some code conversion/porting happening. I&#39;ve always used and heard the terms compiler and interpreter when it comes to converting a language code to a runnable form on a computer system/machine. Transpiler is new to me. How is a transpiler different from a compiler or an interpreter and why it is really needed?

Content Type	Original Author	Original Content on Stackoverflow
Question	user550617	View Question on Stackoverflow
Solution 1 - Scala	Jamil	View Answer on Stackoverflow
Solution 2 - Scala	Suresh Babu	View Answer on Stackoverflow
Solution 3 - Scala	Esmaeil MIRZAEE	View Answer on Stackoverflow

Load Scala file into interpreter to use functions?

Scala Problem Overview

Scala Solutions

Solution 1 - Scala

Solution 2 - Scala

Solution 3 - Scala

Text or Bytestring

Using ISNULL vs using COALESCE for checking a specific condition?

Attributions