switch to go vendoring

vendor/github.com/open-policy-agent/opa/internal/future/filter_imports.go

@@ -0,0 +1,37 @@
+// Copyright 2021 The OPA Authors.  All rights reserved.
+// Use of this source code is governed by an Apache2
+// license that can be found in the LICENSE file.
+
+package future
+
+import "github.com/open-policy-agent/opa/ast"
+
+// FilterFutureImports filters OUT any future imports from the passed slice of
+// `*ast.Import`s.
+func FilterFutureImports(imps []*ast.Import) []*ast.Import {
+	ret := []*ast.Import{}
+	for _, imp := range imps {
+		path := imp.Path.Value.(ast.Ref)
+		if !ast.FutureRootDocument.Equal(path[0]) {
+			ret = append(ret, imp)
+		}
+	}
+	return ret
+}
+
+// IsAllFutureKeywords returns true if the passed *ast.Import is `future.keywords`
+func IsAllFutureKeywords(imp *ast.Import) bool {
+	path := imp.Path.Value.(ast.Ref)
+	return len(path) == 2 &&
+		ast.FutureRootDocument.Equal(path[0]) &&
+		path[1].Equal(ast.StringTerm("keywords"))
+}
+
+// IsFutureKeyword returns true if the passed *ast.Import is `future.keywords.{kw}`
+func IsFutureKeyword(imp *ast.Import, kw string) bool {
+	path := imp.Path.Value.(ast.Ref)
+	return len(path) == 3 &&
+		ast.FutureRootDocument.Equal(path[0]) &&
+		path[1].Equal(ast.StringTerm("keywords")) &&
+		path[2].Equal(ast.StringTerm(kw))
+}

vendor/github.com/open-policy-agent/opa/internal/future/parser_opts.go

@@ -0,0 +1,42 @@
+// Copyright 2021 The OPA Authors.  All rights reserved.
+// Use of this source code is governed by an Apache2
+// license that can be found in the LICENSE file.
+
+package future
+
+import (
+	"fmt"
+
+	"github.com/open-policy-agent/opa/ast"
+)
+
+// ParserOptionsFromFutureImports transforms a slice of `ast.Import`s into the
+// `ast.ParserOptions` that can be used to parse a statement according to the
+// included "future.keywords" and "future.keywords.xyz" imports.
+func ParserOptionsFromFutureImports(imports []*ast.Import) (ast.ParserOptions, error) {
+	popts := ast.ParserOptions{
+		FutureKeywords: []string{},
+	}
+	for _, imp := range imports {
+		path := imp.Path.Value.(ast.Ref)
+		if !ast.FutureRootDocument.Equal(path[0]) {
+			continue
+		}
+		if len(path) >= 2 {
+			if string(path[1].Value.(ast.String)) != "keywords" {
+				return popts, fmt.Errorf("unknown future import: %v", imp)
+			}
+			if len(path) == 2 {
+				// retun, one "future.keywords" import means we can disregard any others
+				return ast.ParserOptions{AllFutureKeywords: true}, nil
+			}
+		}
+		if len(path) == 3 {
+			if imp.Alias != "" {
+				return popts, fmt.Errorf("alias not supported")
+			}
+			popts.FutureKeywords = append(popts.FutureKeywords, string(path[2].Value.(ast.String)))
+		}
+	}
+	return popts, nil
+}