Added set path example

pkg/yqlib/doc/operators/path.md

@@ -122,6 +122,31 @@ a:
   b: things
 ```
 
+## Set path to extract prune deep paths
+Like pick but recursive.
+
+Given a sample.yml file of:
+```yaml
+parentA: bob
+parentB:
+  child1: i am child1
+  child2: i am child2
+parentC:
+  child1: me child1
+  child2: me child2
+```
+then
+```bash
+yq '(.parentB.child2, .parentC.child1) as $i ireduce({}; setpath($i | path; $i))' sample.yml
+```
+will output
+```yaml
+parentB:
+  child2: i am child2
+parentC:
+  child1: me child1
+```
+
 ## Set array path
 Given a sample.yml file of:
 ```yaml

pkg/yqlib/operator_path_test.go

@@ -4,6 +4,16 @@ import (
 	"testing"
 )
 
+var documentToPrune = `
+parentA: bob
+parentB:
+  child1: i am child1
+  child2: i am child2
+parentC:
+  child1: me child1
+  child2: me child2
+`
+
 var pathOperatorScenarios = []expressionScenario{
 	{
 		description: "Map path",
@@ -78,6 +88,15 @@ var pathOperatorScenarios = []expressionScenario{
 			"D0, P[], ()::a:\n    b: things\n",
 		},
 	},
+	{
+		description:    "Set path to extract prune deep paths",
+		subdescription: "Like pick but recursive.",
+		document:       documentToPrune,
+		expression:     `(.parentB.child2, .parentC.child1) as $i ireduce({}; setpath($i | path; $i))`,
+		expected: []string{
+			"D0, P[], (!!map)::parentB:\n    child2: i am child2\nparentC:\n    child1: me child1\n",
+		},
+	},
 	{
 		description: "Set array path",
 		document:    `a: [cat, frog]`,