Make "def width" a private API; expose isWidthKnown instead (#257)

* Make "def width" a private API; expose isWidthKnown instead

Resolves #256.

Since width was used to determine whether getWidth would succeed, I added

    def isWidthKnown: Boolean

but another option would be to expose something like

    def widthOption: Option[Int]

...thoughts?

* Document getWidth/isWidthKnown

* Add widthOption for more idiomatic Scala manipulation of widths

1 files changed, 1 insertions, 1 deletions

diff --git a/src/main/scala/chisel3/util/BitPat.scala b/src/main/scala/chisel3/util/BitPat.scala
index d476f957..26106080 100644
--- a/src/main/scala/chisel3/util/BitPat.scala
+++ b/src/main/scala/chisel3/util/BitPat.scala
@@ -68,7 +68,7 @@ object BitPat {
     */
   def apply(x: UInt): BitPat = {
     require(x.isLit)
-    val len = if (x.width.known) x.getWidth else 0
+    val len = if (x.isWidthKnown) x.getWidth else 0
     apply("b" + x.litValue.toString(2).reverse.padTo(len, "0").reverse.mkString)
   }
 }