From e4d5769f2900147fd6e9046cb3a6873766168a8d Mon Sep 17 00:00:00 2001
From: mfarah <mike.farah@ioof.com.au>
Date: Mon, 5 Oct 2015 14:41:01 +1100
Subject: [PATCH] Added array splat functionality

---
 README.md              | 20 ++++++++++++++++++++
 data_navigator.go      | 18 ++++++++++++++++++
 data_navigator_test.go | 19 +++++++++++++++++--
 3 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index ece11ca4..4e2b59b6 100644
--- a/README.md
+++ b/README.md
@@ -56,6 +56,26 @@ yaml sample.yaml b.e[1].name
 ```
 will output 'sam'
 
+#### Array Splat
+e.g.: given a sample file of
+```yaml
+b:
+  e:
+    - name: fred
+      value: 3
+    - name: sam
+      value: 4
+```
+then
+```
+yaml sample.yaml b.e[*].name
+```
+will output:
+```
+- fred
+- sam
+```
+
 ### Updating yaml
 Given a sample.yaml file of:
 ```yaml
diff --git a/data_navigator.go b/data_navigator.go
index ab71ae86..9806fc62 100644
--- a/data_navigator.go
+++ b/data_navigator.go
@@ -25,6 +25,9 @@ func readMap(context map[interface{}]interface{}, head string, tail []string) in
 func recurse(value interface{}, head string, tail []string) interface{} {
 	switch value.(type) {
 	case []interface{}:
+		if head == "*" {
+			return readArraySplat(value.([]interface{}), tail)
+		}
 		index, err := strconv.ParseInt(head, 10, 64)
 		if err != nil {
 			log.Fatalf("Error accessing array: %v", err)
@@ -48,3 +51,18 @@ func readArray(array []interface{}, head int64, tail []string) interface{} {
 	}
 	return value
 }
+
+func readArraySplat(array []interface{}, tail []string) interface{} {
+	var newArray = make([]interface{}, len(array))
+	for index, value := range array {
+		newArray[index] = calculateValue(value, tail)
+	}
+	return newArray
+}
+
+func calculateValue(value interface{}, tail []string) interface{} {
+	if len(tail) > 0 {
+		return recurse(value, tail[0], tail[1:len(tail)])
+	}
+	return value
+}
diff --git a/data_navigator_test.go b/data_navigator_test.go
index 6b398e69..a7f12a38 100644
--- a/data_navigator_test.go
+++ b/data_navigator_test.go
@@ -8,10 +8,20 @@ import (
 )
 
 var rawData = `
+---
 a: Easy!
 b:
   c: 2
-  d: [3, 4]
+  d:
+    - 3
+    - 4
+e:
+  -
+    name: Fred
+    thing: cat
+  -
+    name: Sam
+    thing: dog
 `
 
 var parsedData map[interface{}]interface{}
@@ -42,6 +52,10 @@ func TestReadMap_with_array_out_of_bounds(t *testing.T) {
 	assertResult(t, nil, readMap(parsedData, "b", []string{"d", "3"}))
 }
 
+func TestReadMap_with_array_splat(t *testing.T) {
+	assertResult(t, "[Fred Sam]", fmt.Sprintf("%v", readMap(parsedData, "e", []string{"*", "name"})))
+}
+
 func TestWrite_simple(t *testing.T) {
 
 	write(parsedData, "b", []string{"c"}, "4")
@@ -52,11 +66,12 @@ func TestWrite_simple(t *testing.T) {
 
 func assertResult(t *testing.T, expectedValue interface{}, actualValue interface{}) {
 	if expectedValue != actualValue {
-		t.Error("Expected <", expectedValue, "> but got <", actualValue, ">")
+		t.Error("Expected <", expectedValue, "> but got <", actualValue, ">", fmt.Sprintf("%T", actualValue))
 	}
 }
 
 func assertResultWithContext(t *testing.T, expectedValue interface{}, actualValue interface{}, context interface{}) {
+
 	if expectedValue != actualValue {
 		t.Error(context)
 		t.Error(": expected <", expectedValue, "> but got <", actualValue, ">")