Fix style of literal creators (#637)

* Fix style of literal creators
Literal creators for UInt, SInt and Bool were declared with parens, but
virtually all uses of these methods do not use parens.  This is for
issue #539.
This fix is an API breaking change. If anyone has used parens, e.g.
val x = 1.U()
This will now be an error

* remove trailing parens from literal creators in IntegerMathTester

2 files changed, 7 insertions, 7 deletions

diff --git a/chiselFrontend/src/main/scala/chisel3/core/package.scala b/chiselFrontend/src/main/scala/chisel3/core/package.scala
index aec5398d..e4a60329 100644
--- a/chiselFrontend/src/main/scala/chisel3/core/package.scala
+++ b/chiselFrontend/src/main/scala/chisel3/core/package.scala
@@ -26,10 +26,10 @@ package chisel3 {
     implicit class fromBigIntToLiteral(val bigint: BigInt) {
       /** Int to UInt conversion, recommended style for constants.
         */
-      def U(): UInt = UInt.Lit(bigint, Width())  // scalastyle:ignore method.name
+      def U: UInt = UInt.Lit(bigint, Width())  // scalastyle:ignore method.name
       /** Int to SInt conversion, recommended style for constants.
         */
-      def S(): SInt = SInt.Lit(bigint, Width())  // scalastyle:ignore method.name
+      def S: SInt = SInt.Lit(bigint, Width())  // scalastyle:ignore method.name
       /** Int to UInt conversion with specified width, recommended style for constants.
         */
       def U(width: Width): UInt = UInt.Lit(bigint, width)  // scalastyle:ignore method.name
@@ -57,7 +57,7 @@ package chisel3 {
     implicit class fromStringToLiteral(val str: String) {
       /** String to UInt parse, recommended style for constants.
         */
-      def U(): UInt = str.asUInt() // scalastyle:ignore method.name
+      def U: UInt = str.asUInt() // scalastyle:ignore method.name
       /** String to UInt parse with specified width, recommended style for constants.
         */
       def U(width: Width): UInt = str.asUInt(width) // scalastyle:ignore method.name
@@ -88,7 +88,7 @@ package chisel3 {
     implicit class fromBooleanToLiteral(val boolean: Boolean) {
       /** Boolean to Bool conversion, recommended style for constants.
         */
-      def B(): Bool = Bool.Lit(boolean)  // scalastyle:ignore method.name
+      def B: Bool = Bool.Lit(boolean)  // scalastyle:ignore method.name
 
       /** Boolean to Bool conversion, recommended style for variables.
         */
diff --git a/src/test/scala/chiselTests/IntegerMathSpec.scala b/src/test/scala/chiselTests/IntegerMathSpec.scala
index 3ccade8e..e78a780c 100644
--- a/src/test/scala/chiselTests/IntegerMathSpec.scala
+++ b/src/test/scala/chiselTests/IntegerMathSpec.scala
@@ -13,9 +13,9 @@ class IntegerMathTester extends BasicTester {
   /* absolute values tests */
 
   val uint = 3.U(4.W)
-  val sint = (-3).S()
-  val sintpos = 3.S()
-  val wrongSIntPos = 4.S()
+  val sint = (-3).S
+  val sintpos = 3.S
+  val wrongSIntPos = 4.S
 
   assert(uint.abs() === uint)
   assert(sint.abs() === sintpos)