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POConfusion with a simple Scala packaging example
 

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    <p>I've been experiencing confusion over packaging classes in Scala and importing packages. Let me start with a pair of simple source files:</p> <h2>file: a/A.scala</h2> <pre><code>package a // Which of these imports should be used? They both seem to work. //import a.b._ import b._ class A { val fieldB = new B } </code></pre> <h2>file: a/b/B.scala</h2> <pre><code>package a.b class B </code></pre> <h2>usage</h2> <p>Compiling with scalac works without complaint with either of the imports above in A.scala</p> <p>Trying to load these files in the REPL works differently:</p> <pre><code>$ scala Welcome to Scala version 2.8.0.r0-b20100714201327 (Java HotSpot(TM) Server VM, Java 1.6.0_20). Type in expressions to have them evaluated. Type :help for more information. scala&gt; :l a/b/B.scala Loading a/b/B.scala... &lt;console&gt;:1: error: illegal start of definition package a.b ^ defined class B scala&gt; :l a/A.scala Loading a/A.scala... &lt;console&gt;:1: error: illegal start of definition package a ^ &lt;console&gt;:5: error: not found: value b import b._ ^ defined class A scala&gt; </code></pre> <p>So, I have a some questions:</p> <ul> <li><p>What is the correct way to do that import in <code>A.scala</code> above?</p></li> <li><p>The compiler seems to be able to figure out if an import is relative to the package we are in or if it is absolute, without the <code>_root_</code>. Is that what I'm seeing?</p></li> <li><p>Am I doing this correctly in the REPL? Why does it seem so unhappy with seeing package statements, and why does the <code>import b._</code> generate an error?</p></li> </ul> <p>Thank you</p> <p>PS I know the directory structure doesn't have to match the packaging. Doing so voluntarily is helping me to be less confused for now.</p>
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