Fix stylistic issues and document standard Chisel generators

1 files changed, 27 insertions, 9 deletions

diff --git a/src/test/scala/chiselTests/ChiselSpec.scala b/src/test/scala/chiselTests/ChiselSpec.scala
index 2d546d00..1fe77a0e 100644
--- a/src/test/scala/chiselTests/ChiselSpec.scala
+++ b/src/test/scala/chiselTests/ChiselSpec.scala
@@ -19,30 +19,48 @@ class ChiselFlatSpec extends FlatSpec with ChiselRunners with Matchers
 
 /** Spec base class for property-based testers. */
 class ChiselPropSpec extends PropSpec with ChiselRunners with PropertyChecks {
-  def popCount(n: Long) = n.toBinaryString.count(_=='1')
+  /** Returns the number of 1s in the binary representation of the input. */
+  def popCount(n: Long): Int = n.toBinaryString.count(_ == '1')
 
+  // Generator for small positive integers.
   val smallPosInts = Gen.choose(1, 7)
+
+  // Generator for widths considered "safe".
   val safeUIntWidth = Gen.choose(1, 30)
+
+  // Generators for integers that fit within "safe" widths.
   val safeUInts = Gen.choose(0, (1 << 30))
+
+  // Generators for vector sizes.
   val vecSizes = Gen.choose(0, 4)
-  val binaryString = for(i <- Arbitrary.arbitrary[Int]) yield "b" + i.toBinaryString
-  def enSequence(n: Int) = Gen.containerOfN[List,Boolean](n,Gen.oneOf(true,false))
 
-  def safeUIntN(n: Int) = for {
+  // Generator for string representing an arbitrary integer.
+  val binaryString = for (i <- Arbitrary.arbitrary[Int]) yield "b" + i.toBinaryString
+
+  // Generator for a sequence of Booleans of size n.
+  def enSequence(n: Int): Gen[List[Boolean]] = Gen.containerOfN[List, Boolean](n, Gen.oneOf(true, false))
+
+  // Generator which gives a width w and a list (of size n) of numbers up to w bits.
+  def safeUIntN(n: Int): Gen[(Int, List[Int])] = for {
     w <- smallPosInts
-    i <- Gen.containerOfN[List,Int](n, Gen.choose(0, (1 << w) - 1))
+    i <- Gen.containerOfN[List, Int](n, Gen.choose(0, (1 << w) - 1))
   } yield (w, i)
+
+  // Generator which gives a width w and a numbers up to w bits.
   val safeUInt = for {
     w <- smallPosInts
     i <- Gen.choose(0, (1 << w) - 1)
   } yield (w, i)
 
-  def safeUIntPairN(n: Int) = for {
+  // Generator which gives a width w and a list (of size n) of a pair of numbers up to w bits.
+  def safeUIntPairN(n: Int): Gen[(Int, List[(Int, Int)])] = for {
     w <- smallPosInts
-    i <- Gen.containerOfN[List,Int](n, Gen.choose(0, (1 << w) - 1))
-    j <- Gen.containerOfN[List,Int](n, Gen.choose(0, (1 << w) - 1))
+    i <- Gen.containerOfN[List, Int](n, Gen.choose(0, (1 << w) - 1))
+    j <- Gen.containerOfN[List, Int](n, Gen.choose(0, (1 << w) - 1))
   } yield (w, i zip j)
-  val safeUIntPair= for {
+
+  // Generator which gives a width w and a pair of numbers up to w bits.
+  val safeUIntPair = for {
     w <- smallPosInts
     i <- Gen.choose(0, (1 << w) - 1)
     j <- Gen.choose(0, (1 << w) - 1)