walk/1

docs/content/3.manual/manual.yml

@@ -1522,6 +1522,33 @@ sections:
                 - 4
                 - 16
 
+      - title: "`walk(f)`"
+        body: |
+
+          The `walk(f)` function applies f recursively to every
+	  component of the input entity.  When an array is
+	  encountered, f is first applied to its elements and then to
+	  the array itself; when an object is encountered, f is first
+	  applied to all the values and then to the object.  In
+	  practice, f will usually test the type of its input, as
+	  illustrated in the following examples.  The first example
+	  highlights the usefulness of processing the elements of an
+	  array of arrays before processing the array itself.  The second
+	  example shows how all the keys of all the objects within the
+	  input can be considered for alteration.
+
+        examples:
+          - program: 'walk(if type == "array" then sort else . end)'
+            input: '[[4, 1, 7], [8, 5, 2], [3, 6, 9]]'
+            output:
+              - '[[1,4,7],[2,5,8],[3,6,9]]'
+
+          - program: 'walk( if type == "object" then with_entries( .key |= sub( "^_+"; "") ) else . end )
+            input: '[ { "_a": { "__b": 2 } } ]'
+            output:
+              - '[{"a":{"b":2}}]'
+
+
       - title: "`..`"
         body: |