Bump cel-go to v0.17.6

vendor/github.com/google/cel-go/ext/lists.go

@@ -0,0 +1,94 @@
+// Copyright 2023 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ext
+
+import (
+	"fmt"
+
+	"github.com/google/cel-go/cel"
+	"github.com/google/cel-go/common/types"
+	"github.com/google/cel-go/common/types/ref"
+	"github.com/google/cel-go/common/types/traits"
+)
+
+// Lists returns a cel.EnvOption to configure extended functions for list manipulation.
+// As a general note, all indices are zero-based.
+// # Slice
+//
+// Returns a new sub-list using the indexes provided.
+//
+//	<list>.slice(<int>, <int>) -> <list>
+//
+// Examples:
+//
+//	[1,2,3,4].slice(1, 3) // return [2, 3]
+//	[1,2,3,4].slice(2, 4) // return [3 ,4]
+func Lists() cel.EnvOption {
+	return cel.Lib(listsLib{})
+}
+
+type listsLib struct{}
+
+// LibraryName implements the SingletonLibrary interface method.
+func (listsLib) LibraryName() string {
+	return "cel.lib.ext.lists"
+}
+
+// CompileOptions implements the Library interface method.
+func (listsLib) CompileOptions() []cel.EnvOption {
+	listType := cel.ListType(cel.TypeParamType("T"))
+	return []cel.EnvOption{
+		cel.Function("slice",
+			cel.MemberOverload("list_slice",
+				[]*cel.Type{listType, cel.IntType, cel.IntType}, listType,
+				cel.FunctionBinding(func(args ...ref.Val) ref.Val {
+					list := args[0].(traits.Lister)
+					start := args[1].(types.Int)
+					end := args[2].(types.Int)
+					result, err := slice(list, start, end)
+					if err != nil {
+						return types.WrapErr(err)
+					}
+					return result
+				}),
+			),
+		),
+	}
+}
+
+// ProgramOptions implements the Library interface method.
+func (listsLib) ProgramOptions() []cel.ProgramOption {
+	return []cel.ProgramOption{}
+}
+
+func slice(list traits.Lister, start, end types.Int) (ref.Val, error) {
+	listLength := list.Size().(types.Int)
+	if start < 0 || end < 0 {
+		return nil, fmt.Errorf("cannot slice(%d, %d), negative indexes not supported", start, end)
+	}
+	if start > end {
+		return nil, fmt.Errorf("cannot slice(%d, %d), start index must be less than or equal to end index", start, end)
+	}
+	if listLength < end {
+		return nil, fmt.Errorf("cannot slice(%d, %d), list is length %d", start, end, listLength)
+	}
+
+	var newList []ref.Val
+	for i := types.Int(start); i < end; i++ {
+		val := list.Get(i)
+		newList = append(newList, val)
+	}
+	return types.DefaultTypeAdapter.NativeToValue(newList), nil
+}