Can now splat maps

Author: mfarah

README.md

@@ -33,6 +33,26 @@ cat sample.yaml | yaml - b.c
 ```
 will output the value of '2'.
 
+### Splat
+Given a sample.yaml file of:
+```yaml
+---
+bob:
+  item1:
+    cats: bananas
+  item2:
+    cats: apples
+```
+then
+```bash
+yaml sample.yaml bob.*.cats
+```
+will output
+```yaml
+- bananas
+- apples
+```
+
 ### Handling '.' in the yaml key
 Given a sample.yaml file of:
 ```yaml
@@ -82,6 +102,8 @@ will output:
 - sam
 ```
 
+
+
 ### Updating yaml
 Given a sample.yaml file of:
 ```yaml

data_navigator.go

@@ -19,10 +19,27 @@ func write(context map[interface{}]interface{}, head string, tail []string, valu
 }
 
 func readMap(context map[interface{}]interface{}, head string, tail []string) interface{} {
+	if head == "*" {
+		return readMapSplat(context, tail)
+	}
 	value := context[head]
 	return calculateValue(value, tail)
 }
 
+func readMapSplat(context map[interface{}]interface{}, tail []string) interface{} {
+	var newArray = make([]interface{}, len(context))
+	var i = 0
+	for _, value := range context {
+		if len(tail) > 0 {
+			newArray[i] = recurse(value, tail[0], tail[1:len(tail)])
+		} else {
+			newArray[i] = value
+		}
+		i++
+	}
+	return newArray
+}
+
 func recurse(value interface{}, head string, tail []string) interface{} {
 	switch value.(type) {
 	case []interface{}:

data_navigator_test.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"gopkg.in/yaml.v2"
 	"os"
+	"sort"
 	"testing"
 )
 
@@ -26,6 +27,32 @@ b:
 	assertResult(t, 2, readMap(data, "b", []string{"c"}))
 }
 
+func TestReadMap_splat(t *testing.T) {
+	var data = parseData(`
+---
+mapSplat:
+  item1: things
+  item2: whatever
+`)
+	assertResult(t, "[things whatever]", fmt.Sprintf("%v", readMap(data, "mapSplat", []string{"*"})))
+}
+
+func TestReadMap_deep_splat(t *testing.T) {
+	var data = parseData(`
+---
+mapSplatDeep:
+  item1:
+    cats: bananas
+  item2:
+    cats: apples
+`)
+
+	var result = readMap(data, "mapSplatDeep", []string{"*", "cats"}).([]interface{})
+	var actual = []string{result[0].(string), result[1].(string)}
+	sort.Strings(actual)
+	assertResult(t, "[apples bananas]", fmt.Sprintf("%v", actual))
+}
+
 func TestReadMap_key_doesnt_exist(t *testing.T) {
 	var data = parseData(`
 ---

sample2.yaml

@@ -1,4 +1,9 @@
 a: Easy! as one two three
 b:
-  c: 3
-  d: [3, 4]
+  c: things
+  d: whatever
+things:
+ thing1:
+  cat: 'fred'
+ thing2:
+  cat: 'sam'