Oron Port soronpo

Taken from https://gitter.im/scala/contributors?at=5c0981af80986419d54dd08d

Stefan Zeiger @szeiger:

I'll try to give a high-level explanation (with imprecise types): In order to build something (like the result of 1.to(10).map(identity)) you use a Builder[E, To] to which you add elements of type E and eventually get a result To. That way a single implementation of map can build different result types. In order to get such a Builder you need a factory, i.e. a () => Builder[E, To]. We call this type CanBuild and pass an implicit instance of it to map. You usually don't care who's doing the building (Range in this case) but for the sake of finding an implicit CanBuild you want the source collection to determine the result type To (e.g. calling map on a List should build another List).

	package AES

	import dfhdl.{apply => _, *}
	export dfhdl.apply

	import scala.annotation.targetName

	//////////////////////////////////////////////////////////////////////////////////////////////////////
	// AES Byte
	//////////////////////////////////////////////////////////////////////////////////////////////////////

	```
	Exception in thread "pool-5-thread-2" java.lang.AssertionError: assertion failed: asTerm called on not-a-Term val <none>
	at scala.runtime.Scala3RunTime$.assertFailed(Scala3RunTime.scala:8)
	at dotty.tools.dotc.core.Symbols$Symbol.asTerm(Symbols.scala:163)
	at dotty.tools.dotc.ast.tpd$.New(tpd.scala:494)
	at dotty.tools.dotc.core.Annotations$Annotation$.apply(Annotations.scala:191)
	at dotty.tools.dotc.core.Annotations$Annotation$.apply(Annotations.scala:182)
	at dotty.tools.dotc.core.classfile.ClassfileParser.parseAttribute$1(ClassfileParser.scala:734)
	at dotty.tools.dotc.core.classfile.ClassfileParser.parseAttributes$$anonfun$1(ClassfileParser.scala:792)
	at scala.runtime.java8.JFunction1$mcVI$sp.apply(JFunction1$mcVI$sp.scala:18)

	error] dotty.tools.dotc.core.Denotations$StaleSymbol: stale symbol; type OutW#32239 in trait CompanionsDFBits$Token$Candidate, defined in Period(1..55, run = 2), is referred to in run Period(1..1, run = 3)
	[error] dotty.tools.dotc.core.Denotations$SingleDenotation.staleSymbolError(Denotations.scala:955)
	[error] dotty.tools.dotc.core.Denotations$SingleDenotation.bringForward(Denotations.scala:754)
	[error] dotty.tools.dotc.core.Denotations$SingleDenotation.toNewRun$1(Denotations.scala:803)
	[error] dotty.tools.dotc.core.Denotations$SingleDenotation.current(Denotations.scala:877)
	[error] dotty.tools.dotc.core.Symbols$Symbol.recomputeDenot(Symbols.scala:122)
	[error] dotty.tools.dotc.core.Symbols$Symbol.computeDenot(Symbols.scala:116)
	[error] dotty.tools.dotc.core.Symbols$Symbol.denot(Symbols.scala:109)
	[error] dotty.tools.dotc.core.Symbols$.toDenot(Symbols.scala:494)
	[error] dotty.tools.dotc.core.Types$NamedType.derivedSelect(Types.scala:2493)

	//This is a DFiant-equivalent design of https://github.com/tommythorn/silice-examples/blob/master/cpu.ice
	import DFiant.*
	class CPU(using DFC) extends DFDesign:
	val leds = DFBits(8) <> OUT
	val rf = DFBits(32).X(16) <> VAR init Vector(
	0, 1, 1, 0, 100, 0, 1
	).padTo(16, 0).map(_.toBits(32))

	// A add, B blt
	val code = DFBits(32).X(32) const Vector(

	2019-12-24 00:34:03
	Full thread dump Java HotSpot(TM) 64-Bit Server VM (25.231-b11 mixed mode):

	"classloader-cache-cleanup-0" #13 daemon prio=5 os_prio=0 tid=0x00000000560d6000 nid=0x41c in Object.wait() [0x000000005b2ef000]
	java.lang.Thread.State: TIMED_WAITING (on object monitor)
	at java.lang.Object.wait(Native Method)
	- waiting on <0x00000000c14784a8> (a java.lang.ref.ReferenceQueue$Lock)
	at java.lang.ref.ReferenceQueue.remove(Unknown Source)
	- locked <0x00000000c14784a8> (a java.lang.ref.ReferenceQueue$Lock)
	at sbt.internal.classpath.ClassLoaderCache$CleanupThread.run(ClassLoaderCache.scala:102)

	[warn] module not found: org.scala-lang#scala-library;2.12.5-bin-7e45827-SNAPSHOT
	[warn] ==== local: tried
	[warn] C:\Users\soronpo\.ivy2\local\org.scala-lang\scala-library\2.12.5-bin-7e45827-SNAPSHOT\ivys\ivy.xml
	[warn] ==== public: tried
	[warn] https://repo1.maven.org/maven2/org/scala-lang/scala-library/2.12.5-bin-7e45827-SNAPSHOT/scala-library-2.12.5-bin-7e45827-SNAPSHOT.pom
	[info] Resolving org.scala-lang#scala-reflect;2.12.5-bin-7e45827-SNAPSHOT ...
	[warn] module not found: org.scala-lang#scala-reflect;2.12.5-bin-7e45827-SNAPSHOT
	[warn] ==== local: tried
	[warn] C:\Users\soronpo\.ivy2\local\org.scala-lang\scala-reflect\2.12.5-bin-7e45827-SNAPSHOT\ivys\ivy.xml
	[warn] ==== public: tried

	Error:scalac: Error: org.jetbrains.jps.incremental.scala.remote.ServerException
	Error compiling the sbt component 'compiler-interface-2.13.0-M3-52.0'
	at sbt.internal.inc.AnalyzingCompiler$.handleCompilationError$1(AnalyzingCompiler.scala:331)
	at sbt.internal.inc.AnalyzingCompiler$.$anonfun$compileSources$4(AnalyzingCompiler.scala:346)
	at sbt.internal.inc.AnalyzingCompiler$.$anonfun$compileSources$4$adapted(AnalyzingCompiler.scala:341)
	at sbt.io.IO$.withTemporaryDirectory(IO.scala:332)
	at sbt.io.IO$.withTemporaryDirectory(IO.scala:340)
	at sbt.internal.inc.AnalyzingCompiler$.$anonfun$compileSources$2(AnalyzingCompiler.scala:341)
	at sbt.internal.inc.AnalyzingCompiler$.$anonfun$compileSources$2$adapted(AnalyzingCompiler.scala:335)
	at sbt.io.IO$.withTemporaryDirectory(IO.scala:332)