Lexer novo, ainda em versão script.

compiler/Lexer.scala

-import io.{Source,BufferedSource}
+#!/usr/bin/scala
+!#
+println("started...")
+case class Token(val value:String, val func:String)
 
-case class Atomo(val valor:String, val token:String)
+val palavrasReservadas = List("begin", "end", "function", "procedure", "var", "program")
+
+// Conjuntos
+val num          = (c:Char) => ('0' to '9').contains(c)
+val op           = (c:Char) => "+-*/=:".contains(c)
+val letra        = (c:Char) => ('a' to 'z').contains(c) || ('A' to 'Z').contains(c) || c=='_'
+val espacoLinTab = (c:Char) => c==' ' || c=='\t' || c=='\n'
+val palavraReservada = (s:String) => palavrasReservadas.contains(s)
+
+//Acoes
+val erro = (msg:String) => {println("Erro: "+msg); sys.exit(1)} 
 
-object Lexer {
-  def getTokens(stream:Iterator[Char]):List[atomo] = {
-    var proximo: Char = ''
-    var acc = ""
- 
-    def PROX = if (stream.hasNext) proximo = stream.next
-    def ADD = acc + proximo
 
-    PROX
-    proximo match { //TODO: Pattern Matching
-      case ' ' || '\t' || '\n' => 
-      case letra =>
-      case numero =>
-      case simbolo_especial =>
+def atomo(str:String) {
+  val iter = str.iterator
+  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")
+        (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 espacoLinTab(c) => /*pula*/
+      case erroCh => erro(erroCh+"")
     }
-    
+    )
   }
-  
 }
+
+
+while (true)
+  atomo(readLine)
\ No newline at end of file