1 files changed, 25 insertions, 0 deletions
diff --git a/src/java_cup/runtime/Scanner.java b/src/java_cup/runtime/Scanner.java
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+++ b/src/java_cup/runtime/Scanner.java
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+package java_cup.runtime;
+
+/**
+ * Defines the Scanner interface, which CUP uses in the default
+ * implementation of <code>lr_parser.scan()</code>.  Integration
+ * of scanners implementing <code>Scanner</code> is facilitated.
+ *
+ * @version last updated 23-Jul-1999
+ * @author David MacMahon <davidm@smartsc.com>
+ */
+
+/* *************************************************
+  Interface Scanner
+  
+  Declares the next_token() method that should be
+  implemented by scanners.  This method is typically
+  called by lr_parser.scan().  End-of-file can be
+  indicated either by returning
+  <code>new Symbol(lr_parser.EOF_sym())</code> or
+  <code>null</code>.
+ ***************************************************/
+public interface Scanner {
+    /** Return the next token, or <code>null</code> on end-of-file. */
+    public Symbol next_token() throws java.lang.Exception;
+}