Use require instead of raw throws for validation requirements

Author: rayrobdod

Base/src/main/scala/CodePoint.scala

@@ -6,7 +6,7 @@ import scala.math.Ordering
  * Represents a unicode codepoint
  */
 final class CodePoint private (val intValue:Int) {
-	if (! Character.isValidCodePoint(intValue)) throw new IllegalArgumentException(s"$intValue")
+	require(Character.isValidCodePoint(intValue), s"$intValue is not a valid codepoint")
 
 	override def toString:String = new String(Array[Int](intValue), 0, 1)
 	override def hashCode:Int = intValue

TimeParser/src/main/scala/Digit.scala

@@ -9,11 +9,8 @@ final class Digits(val value:Int)
 
 object Digit {
 	def apply(x:Char):Digit = {
-		if ('0' <= x && x <= '9') {
-			new Digit(x - '0')
-		} else {
-			throw new IllegalArgumentException("Expected ascii digit")
-		}
+		require('0' <= x && x <= '9', "Expected ascii digit")
+		new Digit(x - '0')
 	}
 
 	implicit def given_Repeated:Repeated[Digit, Digits] = new Repeated[Digit, Digits]{