Add OTTL get editor function

pkg/ottl/ottlfuncs/func_get.go

@@ -0,0 +1,35 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package ottlfuncs // import "github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl/ottlfuncs"
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl"
+)
+
+type GetArguments[K any] struct {
+	Value ottl.Getter[K]
+}
+
+func NewGetFactory[K any]() ottl.Factory[K] {
+	return ottl.NewFactory("get", &GetArguments[K]{}, createGetFunction[K])
+}
+
+func createGetFunction[K any](_ ottl.FunctionContext, oArgs ottl.Arguments) (ottl.ExprFunc[K], error) {
+	args, ok := oArgs.(*GetArguments[K])
+
+	if !ok {
+		return nil, fmt.Errorf("GetFactory args must be of type *GetArguments[K]")
+	}
+
+	return get(args.Value), nil
+}
+
+func get[K any](value ottl.Getter[K]) ottl.ExprFunc[K] {
+	return func(ctx context.Context, tCtx K) (any, error) {
+		return value.Get(ctx, tCtx)
+	}
+}

pkg/ottl/ottlfuncs/func_get_test.go

@@ -0,0 +1,71 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package ottlfuncs
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"go.opentelemetry.io/collector/pdata/pcommon"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl"
+)
+
+func Test_get(t *testing.T) {
+	tests := []struct {
+		name   string
+		getter ottl.Getter[any]
+		want   pcommon.Value
+	}{
+		{
+			name: "get string",
+			getter: ottl.StandardGetSetter[any]{
+				Getter: func(_ context.Context, _ any) (any, error) {
+					return "a", nil
+				},
+			},
+			want: pcommon.NewValueStr("a"),
+		},
+		{
+			name: "get int",
+			getter: ottl.StandardGetSetter[any]{
+				Getter: func(_ context.Context, _ any) (any, error) {
+					return 11, nil
+				},
+			},
+			want: pcommon.NewValueInt(11),
+		},
+		{
+			name: "get double",
+			getter: ottl.StandardGetSetter[any]{
+				Getter: func(_ context.Context, _ any) (any, error) {
+					return 104.12, nil
+				},
+			},
+			want: pcommon.NewValueDouble(104.12),
+		},
+		{
+			name: "nil",
+			getter: ottl.StandardGetSetter[any]{
+				Getter: func(_ context.Context, _ any) (any, error) {
+					return nil, nil
+				},
+			},
+			want: pcommon.NewValueEmpty(),
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			exprFunc := get(tt.getter)
+
+			result, err := exprFunc(context.Background(), nil)
+			assert.NoError(t, err)
+
+			actual := pcommon.NewValueEmpty()
+			assert.NoError(t, actual.FromRaw(result))
+			assert.Equal(t, tt.want, actual)
+		})
+	}
+}

pkg/ottl/ottlfuncs/functions.go

@@ -10,6 +10,7 @@ import (
 func StandardFuncs[K any]() map[string]ottl.Factory[K] {
 	f := []ottl.Factory[K]{
 		// Editors
+		NewGetFactory[K](),
 		NewDeleteKeyFactory[K](),
 		NewDeleteMatchingKeysFactory[K](),
 		NewKeepMatchingKeysFactory[K](),