Split ConfigIncludeContext from Parseable out into its own file

config/src/main/java/com/typesafe/config/impl/Parseable.java

@@ -65,12 +65,7 @@ public abstract class Parseable implements ConfigParseable {
     protected void postConstruct(ConfigParseOptions baseOptions) {
         this.initialOptions = fixupOptions(baseOptions);
 
-        this.includeContext = new ConfigIncludeContext() {
+        this.includeContext = new SimpleIncludeContext(this);
-            @Override
-            public ConfigParseable relativeTo(String filename) {
-                return Parseable.this.relativeTo(filename);
-            }
-        };
 
         if (initialOptions.getOriginDescription() != null)
             initialOrigin = SimpleConfigOrigin.newSimple(initialOptions.getOriginDescription());
@@ -80,6 +75,7 @@ public abstract class Parseable implements ConfigParseable {
 
     // the general idea is that any work should be in here, not in the
     // constructor,
+
     // so that exceptions are thrown from the public parse() function and not
     // from the creation of the Parseable. Essentially this is a lazy field.
     // The parser should close the reader when it's done with it.

config/src/main/java/com/typesafe/config/impl/SimpleIncludeContext.java

@@ -0,0 +1,32 @@
+/**
+ *   Copyright (C) 2011-2012 Typesafe Inc. <http://typesafe.com>
+ */
+package com.typesafe.config.impl;
+
+import com.typesafe.config.ConfigIncludeContext;
+import com.typesafe.config.ConfigParseable;
+
+class SimpleIncludeContext implements ConfigIncludeContext {
+
+    private final Parseable parseable;
+
+    SimpleIncludeContext(Parseable parseable) {
+        this.parseable = parseable;
+    }
+
+    SimpleIncludeContext() {
+        this(null);
+    }
+
+    SimpleIncludeContext withParseable(Parseable parseable) {
+        return new SimpleIncludeContext(parseable);
+    }
+
+    @Override
+    public ConfigParseable relativeTo(String filename) {
+        if (parseable != null)
+            return parseable.relativeTo(filename);
+        else
+            return null;
+    }
+}