Better version, but still things left to do.

compiler/Lexer.scala

@@ -12,36 +12,58 @@ val letra        = (c:Char) => ('a' to 'z').contains(c) || ('A' to 'Z').contains
 val espacoLinTab = (c:Char) => c==' ' || c=='\t' || c=='\n'
 val palavraReservada = (s:String) => palavrasReservadas.contains(s)
 
+//Verificadores
+def verificaIdentificador(str:String) = if ( str.exists{(c) => !(num(c) || letra(c)) } ) erro(str+" nao eh identificador valido")
+def verificaNumero(str:String) = if ( str.exists{(c) => !num(c)} ) erro(str+" nao eh numero")
+
 //Acoes
 val erro = (msg:String) => {println("Erro: "+msg); sys.exit(1)} 
 
 
+def take(iter:BufferedIterator[Char]) = {
+  var acc=""
+  while ( //TODO
+    val c = iter.head 
+    if (! espacoLinTab(c) && ! op(c)) {
+      acc += c
+    }
+  }
+}
+
 def atomo(str:String) {
-  val iter = str.iterator
+  val iter = str.iterator.buffered
   while (iter.hasNext) {
-    def take(iter:Iterator[Char]) = iter.takeWhile{(c) => ! espacoLinTab(c)}.mkString
-    iter.dropWhile(espacoLinTab)
     val c = iter.next
-    var acc = ""
-    println(
-    c match {
-      case c if num(c) =>
-        acc = c + take(iter)
-        if ( acc.exists{(c) => !num(c)} ) erro(acc+" nao eh numero")
+    println( c match {
+
+      case c if num(c) => //NUMERO
+        val acc = c + take(iter)
+        println("prox: "+iter.head)
+        verificaNumero(acc)
         (acc,"numero")
-      case c if op(c) => (c, "op") 
-      case c if letra(c) => (c, "letra")
-        acc = c + take(iter)
-        if ( acc.exists{(c) => !(num(c) || letra(c)) } ) erro(acc+" nao eh identificador valido")
-        if (palavraReservada(acc)) (acc,"reservado")
-        else (acc, "identificador")
+
+      case c if op(c) => //OPERADOR
+        if ((c==':') && (iter.head == '='))
+          (c+""+iter.next, "op")
+        else
+          (c, "op")
+
+      case c if letra(c) => //IDENTIFICADOR
+        val acc = c + take(iter)
+        verificaIdentificador(acc)
+        if (palavraReservada(acc))
+          (acc,"reservado")
+        else
+          (acc, "identificador")
+      
       case c if espacoLinTab(c) => /*pula*/
+        iter.dropWhile(espacoLinTab)
+        ""
       case erroCh => erro(erroCh+"")
-    }
-    )
+    })
   }
 }
 
 
 while (true)
-  atomo(readLine)
\ No newline at end of file
+  atomo(readLine)