tpl: Add uniq function

diff --git a/docs/content/templates/functions.md b/docs/content/templates/functions.md
index c514a4ec84c437ea1047b2ae67dffb4a39e08a74..a1cf9e27b7036a14b66ed687068f48fbd8bd3c8f 100644 (file)
--- a/docs/content/templates/functions.md
+++ b/docs/content/templates/functions.md
@@ -373,6 +373,15 @@ e.g.
        {{ .Content }}
     {{ end }}
 
+
+### uniq
+
+Takes in a slice or array and returns a slice with subsequent duplicate elements removed.
+
+    {{ uniq (slice 1 2 3 2) }}
+    {{ slice 1 2 3 2 | uniq }}
+    <!-- both return [1 2 3] -->
+
 ## Files
 
 ### readDir

diff --git a/tpl/collections/collections.go b/tpl/collections/collections.go
index a6331edfe0cde49270cf35f307dff16269d5aeee..b025c76704f7f17f57521019d66a39c037582514 100644 (file)
--- a/tpl/collections/collections.go
+++ b/tpl/collections/collections.go
@@ -587,3 +587,41 @@ func (ns *Namespace) Union(l1, l2 interface{}) (interface{}, error) {
                return nil, errors.New("can't iterate over " + reflect.ValueOf(l1).Type().String())
        }
 }
+
+// Uniq takes in a slice or array and returns a slice with subsequent
+// duplicate elements removed.
+func (ns *Namespace) Uniq(l interface{}) (interface{}, error) {
+       if l == nil {
+               return make([]interface{}, 0), nil
+       }
+
+       lv := reflect.ValueOf(l)
+       lv, isNil := indirect(lv)
+       if isNil {
+               return nil, errors.New("invalid nil argument to Uniq")
+       }
+
+       var ret reflect.Value
+
+       switch lv.Kind() {
+       case reflect.Slice:
+               ret = reflect.MakeSlice(lv.Type(), 0, 0)
+       case reflect.Array:
+               ret = reflect.MakeSlice(reflect.SliceOf(lv.Type().Elem()), 0, 0)
+       default:
+               return nil, errors.New("Can't use Uniq on " + reflect.ValueOf(lv).Type().String())
+       }
+
+       for i := 0; i != lv.Len(); i++ {
+               lvv := lv.Index(i)
+               lvv, isNil := indirect(lvv)
+               if isNil {
+                       continue
+               }
+
+               if !ns.In(ret.Interface(), lvv.Interface()) {
+                       ret = reflect.Append(ret, lvv)
+               }
+       }
+       return ret.Interface(), nil
+}

diff --git a/tpl/collections/collections_test.go b/tpl/collections/collections_test.go
index 6a3d7b9e477bbc0a843230bce4c681818b4cc003..9943f439e9b57d299b5fc152debff4f12b45f9bb 100644 (file)
--- a/tpl/collections/collections_test.go
+++ b/tpl/collections/collections_test.go
@@ -603,6 +603,42 @@ func TestUnion(t *testing.T) {
        }
 }
 
+func TestUniq(t *testing.T) {
+       t.Parallel()
+
+       ns := New(&deps.Deps{})
+       for i, test := range []struct {
+               l      interface{}
+               expect interface{}
+               isErr  bool
+       }{
+               {[]string{"a", "b", "c"}, []string{"a", "b", "c"}, false},
+               {[]string{"a", "b", "c", "c"}, []string{"a", "b", "c"}, false},
+               {[]string{"a", "b", "b", "c"}, []string{"a", "b", "c"}, false},
+               {[]string{"a", "b", "c", "b"}, []string{"a", "b", "c"}, false},
+               {[]int{1, 2, 3}, []int{1, 2, 3}, false},
+               {[]int{1, 2, 3, 3}, []int{1, 2, 3}, false},
+               {[]int{1, 2, 2, 3}, []int{1, 2, 3}, false},
+               {[]int{1, 2, 3, 2}, []int{1, 2, 3}, false},
+               {[4]int{1, 2, 3, 2}, []int{1, 2, 3}, false},
+               {nil, make([]interface{}, 0), false},
+               // should-errors
+               {1, 1, true},
+               {"foo", "fo", true},
+       } {
+               errMsg := fmt.Sprintf("[%d] %v", i, test)
+
+               result, err := ns.Uniq(test.l)
+               if test.isErr {
+                       assert.Error(t, err, errMsg)
+                       continue
+               }
+
+               assert.NoError(t, err, errMsg)
+               assert.Equal(t, test.expect, result, errMsg)
+       }
+}
+
 func (x *TstX) TstRp() string {
        return "r" + x.A
 }

diff --git a/tpl/collections/init.go b/tpl/collections/init.go
index fa786684bd2d1e437a9d27b14d6d4fa2010e3d00..25ef64e1a11c96484f34a7f9fab4465ae48846fa 100644 (file)
--- a/tpl/collections/init.go
+++ b/tpl/collections/init.go
@@ -137,6 +137,12 @@ func init() {
                                {`{{ seq 3 }}`, `[1 2 3]`},
                        },
                )
+               ns.AddMethodMapping(ctx.Uniq,
+                       []string{"uniq"},
+                       [][2]string{
+                               {`{{ slice 1 2 3 2 | uniq }}`, `[1 2 3]`},
+                       },
+               )
 
                return ns