Fix syntax in Selection/Projection examples

spring-expression/src/main/java/org/springframework/expression/spel/ast/Projection.java

@@ -33,12 +33,15 @@ import org.springframework.util.ObjectUtils;
 
 /**
  * Represents projection, where a given operation is performed on all elements in some
- * input sequence, returning a new sequence of the same size. For example:
- * "{1,2,3,4,5,6,7,8,9,10}.!{#isEven(#this)}" returns "[n, y, n, y, n, y, n, y, n, y]"
+ * input sequence, returning a new sequence of the same size.
+ *
+ * <p>For example: <code>{1,2,3,4,5,6,7,8,9,10}.![#isEven(#this)]</code> evaluates
+ * to {@code [n, y, n, y, n, y, n, y, n, y]}.
  *
  * @author Andy Clement
  * @author Mark Fisher
  * @author Juergen Hoeller
+ * @author Sam Brannen
  * @since 3.0
  */
 public class Projection extends SpelNodeImpl {
@@ -64,9 +67,9 @@ public class Projection extends SpelNodeImpl {
 
 		// When the input is a map, we push a special context object on the stack
 		// before calling the specified operation. This special context object
-		// has two fields 'key' and 'value' that refer to the map entries key
-		// and value, and they can be referenced in the operation
-		// eg. {'a':'y','b':'n'}.![value=='y'?key:null]" == ['a', null]
+		// has two fields 'key' and 'value' that refer to the map entry's key
+		// and value, and they can be referenced in the operation -- for example,
+		// {'a':'y', 'b':'n'}.![value == 'y' ? key : null] evaluates to ['a', null].
 		if (operand instanceof Map<?, ?> mapData) {
 			List<Object> result = new ArrayList<>();
 			for (Map.Entry<?, ?> entry : mapData.entrySet()) {

spring-expression/src/main/java/org/springframework/expression/spel/ast/Selection.java

@@ -37,11 +37,11 @@ import org.springframework.util.ObjectUtils;
 /**
  * Represents selection over a map or collection.
  *
- * <p>For example, <code>{1,2,3,4,5,6,7,8,9,10}.?{#isEven(#this)}</code> evaluates
+ * <p>For example, <code>{1,2,3,4,5,6,7,8,9,10}.?[#isEven(#this)]</code> evaluates
  * to {@code [2, 4, 6, 8, 10]}.
  *
- * <p>Basically a subset of the input data is returned based on the
- * evaluation of the expression supplied as selection criteria.
+ * <p>Basically a subset of the input data is returned based on the evaluation of
+ * the expression supplied as selection criteria.
  *
  * @author Andy Clement
  * @author Mark Fisher