HasSpreadsheetReference.toSpreadsheetSelection

Author: mP1

src/main/java/walkingkooka/spreadsheet/reference/HasSpreadsheetReference.java

@@ -32,6 +32,19 @@ static <H extends HasSpreadsheetReference<R>, R extends Comparable<R>> Comparato
         return (l, r) -> l.reference().compareTo(r.reference());
     }
 
+    /**
+     * Helper that attempts to cast the {@link walkingkooka.tree.expression.ExpressionReference} to
+     * {@link SpreadsheetSelection} if possible or throwing a {@link IllegalArgumentException}.
+     */
+    default SpreadsheetSelection toSpreadsheetSelection() {
+        final R reference = this.reference();
+        if(reference instanceof SpreadsheetSelection) {
+            return (SpreadsheetSelection) reference;
+        }
+
+        throw new IllegalArgumentException("Not a " + SpreadsheetSelection.class.getSimpleName() + ": " + reference);
+    }
+
     /**
      * Returns the reference for the spreadsheet unit.
      */

src/test/java/walkingkooka/spreadsheet/formula/parser/TemplateValueNameSpreadsheetFormulaParserTokenTest.java

@@ -126,4 +126,9 @@ public void testReference() {
             this.value()
         );
     }
+
+    @Override
+    public void testPropertiesNeverReturnNull() {
+        throw new UnsupportedOperationException();
+    }
 }