Added recurse examples

pkg/yqlib/doc/Recursive Descent.md

@@ -32,6 +32,48 @@ a: frog
 frog
 ```
 
+## Recursively find nodes with keys
+Given a sample.yml file of:
+```yaml
+a:
+  name: frog
+  b:
+    name: blog
+    age: 12
+```
+then
+```bash
+yq eval '.. | select(has("name"))' sample.yml
+```
+will output
+```yaml
+name: frog
+b:
+  name: blog
+  age: 12
+name: blog
+age: 12
+```
+
+## Recursively find nodes with values
+Given a sample.yml file of:
+```yaml
+a:
+  nameA: frog
+  b:
+    nameB: frog
+    age: 12
+```
+then
+```bash
+yq eval '.. | select(. == "frog")' sample.yml
+```
+will output
+```yaml
+frog
+frog
+```
+
 ## Recurse map (values and keys)
 Note that the map key appears in the results
 

pkg/yqlib/operator_recursive_descent_test.go

@@ -62,6 +62,24 @@ var recursiveDescentOperatorScenarios = []expressionScenario{
 			"D0, P[a], (!!str)::frog\n",
 		},
 	},
+	{
+		description: "Recursively find nodes with keys",
+		document:    `{a: {name: frog, b: {name: blog, age: 12}}}`,
+		expression:  `.. | select(has("name"))`,
+		expected: []string{
+			"D0, P[a], (!!map)::{name: frog, b: {name: blog, age: 12}}\n",
+			"D0, P[a b], (!!map)::{name: blog, age: 12}\n",
+		},
+	},
+	{
+		description: "Recursively find nodes with values",
+		document:    `{a: {nameA: frog, b: {nameB: frog, age: 12}}}`,
+		expression:  `.. | select(. == "frog")`,
+		expected: []string{
+			"D0, P[a nameA], (!!str)::frog\n",
+			"D0, P[a b nameB], (!!str)::frog\n",
+		},
+	},
 	{
 		description:    "Recurse map (values and keys)",
 		subdescription: "Note that the map key appears in the results",