diff options
Diffstat (limited to 'vendor/github.com/authzed/cel-go/parser/options.go')
| -rw-r--r-- | vendor/github.com/authzed/cel-go/parser/options.go | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/vendor/github.com/authzed/cel-go/parser/options.go b/vendor/github.com/authzed/cel-go/parser/options.go new file mode 100644 index 0000000..61fc3ad --- /dev/null +++ b/vendor/github.com/authzed/cel-go/parser/options.go @@ -0,0 +1,140 @@ +// Copyright 2021 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 parser + +import "fmt" + +type options struct { + maxRecursionDepth int + errorReportingLimit int + errorRecoveryTokenLookaheadLimit int + errorRecoveryLimit int + expressionSizeCodePointLimit int + macros map[string]Macro + populateMacroCalls bool + enableOptionalSyntax bool + enableVariadicOperatorASTs bool +} + +// Option configures the behavior of the parser. +type Option func(*options) error + +// MaxRecursionDepth limits the maximum depth the parser will attempt to parse the expression before giving up. +func MaxRecursionDepth(limit int) Option { + return func(opts *options) error { + if limit < -1 { + return fmt.Errorf("max recursion depth must be greater than or equal to -1: %d", limit) + } + opts.maxRecursionDepth = limit + return nil + } +} + +// ErrorRecoveryLookaheadTokenLimit limits the number of lexer tokens that may be considered during error recovery. +// +// Error recovery often involves looking ahead in the input to determine if there's a point at which parsing may +// successfully resume. In some pathological cases, the parser can look through quite a large set of input which +// in turn generates a lot of back-tracking and performance degredation. +// +// The limit must be >= 1, and is recommended to be less than the default of 256. +func ErrorRecoveryLookaheadTokenLimit(limit int) Option { + return func(opts *options) error { + if limit < 1 { + return fmt.Errorf("error recovery lookahead token limit must be at least 1: %d", limit) + } + opts.errorRecoveryTokenLookaheadLimit = limit + return nil + } +} + +// ErrorRecoveryLimit limits the number of attempts the parser will perform to recover from an error. +func ErrorRecoveryLimit(limit int) Option { + return func(opts *options) error { + if limit < -1 { + return fmt.Errorf("error recovery limit must be greater than or equal to -1: %d", limit) + } + opts.errorRecoveryLimit = limit + return nil + } +} + +// ErrorReportingLimit limits the number of syntax error reports before terminating parsing. +// +// The limit must be at least 1. If unset, the limit will be 100. +func ErrorReportingLimit(limit int) Option { + return func(opts *options) error { + if limit < 1 { + return fmt.Errorf("error reporting limit must be at least 1: %d", limit) + } + opts.errorReportingLimit = limit + return nil + } +} + +// ExpressionSizeCodePointLimit is an option which limits the maximum code point count of an +// expression. +func ExpressionSizeCodePointLimit(expressionSizeCodePointLimit int) Option { + return func(opts *options) error { + if expressionSizeCodePointLimit < -1 { + return fmt.Errorf("expression size code point limit must be greater than or equal to -1: %d", expressionSizeCodePointLimit) + } + opts.expressionSizeCodePointLimit = expressionSizeCodePointLimit + return nil + } +} + +// Macros adds the given macros to the parser. +func Macros(macros ...Macro) Option { + return func(opts *options) error { + for _, m := range macros { + if m != nil { + if opts.macros == nil { + opts.macros = make(map[string]Macro) + } + opts.macros[m.MacroKey()] = m + } + } + return nil + } +} + +// PopulateMacroCalls ensures that the original call signatures replaced by expanded macros +// are preserved in the `SourceInfo` of parse result. +func PopulateMacroCalls(populateMacroCalls bool) Option { + return func(opts *options) error { + opts.populateMacroCalls = populateMacroCalls + return nil + } +} + +// EnableOptionalSyntax enables syntax for optional field and index selection. +func EnableOptionalSyntax(optionalSyntax bool) Option { + return func(opts *options) error { + opts.enableOptionalSyntax = optionalSyntax + return nil + } +} + +// EnableVariadicOperatorASTs enables a compact representation of chained like-kind commutative +// operators. e.g. `a || b || c || d` -> `call(op='||', args=[a, b, c, d])` +// +// The benefit of enabling variadic operators ASTs is a more compact representation deeply nested +// logic graphs. +func EnableVariadicOperatorASTs(varArgASTs bool) Option { + return func(opts *options) error { + opts.enableVariadicOperatorASTs = varArgASTs + return nil + } +} |
