Add lexing for #unspecified literal (from Z3 4.8.10)

Author: jad-hamza

src/main/scala/smtlib/lexer/Lexer.scala

@@ -123,9 +123,13 @@ class Lexer(reader: java.io.Reader) {
           case 'b' => BinaryLit(readBinary())
           case 'x' => HexadecimalLit(readHexadecimal())
           case c => {
-            throw new UnexpectedCharException(c,
-              Position(_currentLine, _currentCol), 
-              "'#' should be followed by a radix 'b' or 'x'")
+            val s = readSymbol(c)
+            if (s == "unspecified")
+              SymbolLit("#unspecified")
+            else
+              throw new UnexpectedCharException(c,
+                Position(_currentLine, _currentCol),
+                "'#' should be followed by a radix 'b' or 'x', or by 'unspecified'")
           }
         }
       }

src/main/scala/smtlib/lexer/Tokens.scala

@@ -36,7 +36,6 @@ object Tokens {
   case class HexadecimalLit(content: Hexadecimal) extends Token(HexadecimalLitKind) {
     override def toString = content.toString
   }
-
   sealed trait TokenKind
 
   case object OParen extends TokenKind /* ( */

src/main/scala/smtlib/parser/ParserCommon.scala

@@ -74,6 +74,7 @@ trait ParserCommon {
     check(token, expected)
     token
   }
+
   /*
    * Make sure the next token is exactly ``expected`` (usually a symbol lit)
    */
@@ -342,8 +343,8 @@ trait ParserCommon {
       case Tokens.StringLitKind => parseString
       case Tokens.KeywordKind => parseKeyword
       case Tokens.OParen => parseSList
-      case kind => 
-        expected(peekToken, 
+      case kind =>
+        expected(peekToken,
                  Tokens.SymbolLitKind, Tokens.NumeralLitKind, Tokens.BinaryLitKind,
                  Tokens.HexadecimalLitKind, Tokens.DecimalLitKind, Tokens.StringLitKind,
                  Tokens.KeywordKind, Tokens.OParen)