Better support for homogenous lists

toml.go

@@ -122,6 +122,94 @@ func (t *Tree) GetPath(keys []string) interface{} {
 	}
 }
 
+// GetArray returns the value at key in the Tree.
+// It returns []string, []int64, etc type if key has homogeneous lists
+// Key is a dot-separated path (e.g. a.b.c) without single/double quoted strings.
+// Returns nil if the path does not exist in the tree.
+// If keys is of length zero, the current tree is returned.
+func (t *Tree) GetArray(key string) interface{} {
+	if key == "" {
+		return t
+	}
+	return t.GetArrayPath(strings.Split(key, "."))
+}
+
+// GetArrayPath returns the element in the tree indicated by 'keys'.
+// If keys is of length zero, the current tree is returned.
+func (t *Tree) GetArrayPath(keys []string) interface{} {
+	if len(keys) == 0 {
+		return t
+	}
+	subtree := t
+	for _, intermediateKey := range keys[:len(keys)-1] {
+		value, exists := subtree.values[intermediateKey]
+		if !exists {
+			return nil
+		}
+		switch node := value.(type) {
+		case *Tree:
+			subtree = node
+		case []*Tree:
+			// go to most recent element
+			if len(node) == 0 {
+				return nil
+			}
+			subtree = node[len(node)-1]
+		default:
+			return nil // cannot navigate through other node types
+		}
+	}
+	// branch based on final node type
+	switch node := subtree.values[keys[len(keys)-1]].(type) {
+	case *tomlValue:
+		switch n := node.value.(type) {
+		case []interface{}:
+			return getArray(n)
+		default:
+			return node.value
+		}
+	default:
+		return node
+	}
+}
+
+// if homogeneous array, then return slice type object over []interface{}
+func getArray(n []interface{}) interface{} {
+	var s []string
+	var b []byte
+	var i64 []int64
+	var f64 []float64
+	var bl []bool
+	for _, value := range n {
+		switch v := value.(type) {
+		case string:
+			s = append(s, v)
+		case byte:
+			b = append(b, v)
+		case int64:
+			i64 = append(i64, v)
+		case float64:
+			f64 = append(f64, v)
+		case bool:
+			bl = append(bl, v)
+		default:
+			return n
+		}
+	}
+	if len(s) == len(n) {
+		return s
+	} else if len(b) == len(n) {
+		return b
+	} else if len(i64) == len(n) {
+		return i64
+	} else if len(f64) == len(n) {
+		return f64
+	} else if len(bl) == len(n) {
+		return bl
+	}
+	return n
+}
+
 // GetPosition returns the position of the given key.
 func (t *Tree) GetPosition(key string) Position {
 	if key == "" {

toml_test.go

@@ -3,6 +3,7 @@
 package toml
 
 import (
+	"reflect"
 	"testing"
 )
 
@@ -39,6 +40,41 @@ func TestTomlGet(t *testing.T) {
 	}
 }
 
+func TestTomlGetArray(t *testing.T) {
+	tree, _ := Load(`
+		[test]
+		key = ["one", "two"]
+		key2 = [true, false, false]
+		key3 = [1.5,2.5]
+	`)
+
+	if tree.GetArray("") != tree {
+		t.Errorf("GetArray should return the tree itself when given an empty path")
+	}
+
+	expect := []string{"one", "two"}
+	actual := tree.GetArray("test.key").([]string)
+	if !reflect.DeepEqual(actual, expect) {
+		t.Errorf("GetArray should return the []string value")
+	}
+
+	expect2 := []bool{true, false, false}
+	actual2 := tree.GetArray("test.key2").([]bool)
+	if !reflect.DeepEqual(actual2, expect2) {
+		t.Errorf("GetArray should return the []bool value")
+	}
+
+	expect3 := []float64{1.5,2.5}
+	actual3 := tree.GetArray("test.key3").([]float64)
+	if !reflect.DeepEqual(actual3, expect3) {
+		t.Errorf("GetArray should return the []float64 value")
+	}
+
+	if tree.GetArray(`\`) != nil {
+		t.Errorf("should return nil when the key is malformed")
+	}
+}
+
 func TestTomlGetDefault(t *testing.T) {
 	tree, _ := Load(`
 		[test]
@@ -148,6 +184,32 @@ func TestTomlGetPath(t *testing.T) {
 	}
 }
 
+func TestTomlGetArrayPath(t *testing.T) {
+	node := newTree()
+	//TODO: set other node data
+
+	for idx, item := range []struct {
+		Path     []string
+		Expected *Tree
+	}{
+		{ // empty path test
+			[]string{},
+			node,
+		},
+	} {
+		result := node.GetArrayPath(item.Path)
+		if result != item.Expected {
+			t.Errorf("GetArrayPath[%d] %v - expected %v, got %v instead.", idx, item.Path, item.Expected, result)
+		}
+	}
+
+	tree, _ := Load("[foo.bar]\na=1\nb=2\n[baz.foo]\na=3\nb=4\n[gorf.foo]\na=5\nb=6")
+	if tree.GetArrayPath([]string{"whatever"}) != nil {
+		t.Error("GetArrayPath should return nil when the key does not exist")
+	}
+
+}
+
 func TestTomlFromMap(t *testing.T) {
 	simpleMap := map[string]interface{}{"hello": 42}
 	tree, err := TreeFromMap(simpleMap)