ceph-csi/vendor/github.com/google/cel-go/ext/strings.go
dependabot[bot] e5d9b68d36 rebase: bump the golang-dependencies group with 1 update
Bumps the golang-dependencies group with 1 update: [golang.org/x/crypto](https://github.com/golang/crypto).


Updates `golang.org/x/crypto` from 0.16.0 to 0.17.0
- [Commits](https://github.com/golang/crypto/compare/v0.16.0...v0.17.0)

---
updated-dependencies:
- dependency-name: golang.org/x/crypto
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: golang-dependencies
...

Signed-off-by: dependabot[bot] <support@github.com>
2023-12-21 13:34:39 +00:00

1096 lines
36 KiB
Go

// Copyright 2020 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 contains CEL extension libraries where each library defines a related set of
// constants, functions, macros, or other configuration settings which may not be covered by
// the core CEL spec.
package ext
import (
"fmt"
"math"
"reflect"
"sort"
"strings"
"unicode"
"unicode/utf8"
"golang.org/x/text/language"
"golang.org/x/text/message"
"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"
"github.com/google/cel-go/interpreter"
)
const (
defaultLocale = "en-US"
defaultPrecision = 6
)
// Strings returns a cel.EnvOption to configure extended functions for string manipulation.
// As a general note, all indices are zero-based.
//
// # CharAt
//
// Returns the character at the given position. If the position is negative, or greater than
// the length of the string, the function will produce an error:
//
// <string>.charAt(<int>) -> <string>
//
// Examples:
//
// 'hello'.charAt(4) // return 'o'
// 'hello'.charAt(5) // return ''
// 'hello'.charAt(-1) // error
//
// # Format
//
// Introduced at version: 1
//
// Returns a new string with substitutions being performed, printf-style.
// The valid formatting clauses are:
//
// `%s` - substitutes a string. This can also be used on bools, lists, maps, bytes,
// Duration and Timestamp, in addition to all numerical types (int, uint, and double).
// Note that the dot/period decimal separator will always be used when printing a list
// or map that contains a double, and that null can be passed (which results in the
// string "null") in addition to types.
// `%d` - substitutes an integer.
// `%f` - substitutes a double with fixed-point precision. The default precision is 6, but
// this can be adjusted. The strings `Infinity`, `-Infinity`, and `NaN` are also valid input
// for this clause.
// `%e` - substitutes a double in scientific notation. The default precision is 6, but this
// can be adjusted.
// `%b` - substitutes an integer with its equivalent binary string. Can also be used on bools.
// `%x` - substitutes an integer with its equivalent in hexadecimal, or if given a string or
// bytes, will output each character's equivalent in hexadecimal.
// `%X` - same as above, but with A-F capitalized.
// `%o` - substitutes an integer with its equivalent in octal.
//
// <string>.format(<list>) -> <string>
//
// Examples:
//
// "this is a string: %s\nand an integer: %d".format(["str", 42]) // returns "this is a string: str\nand an integer: 42"
// "a double substituted with %%s: %s".format([64.2]) // returns "a double substituted with %s: 64.2"
// "string type: %s".format([type(string)]) // returns "string type: string"
// "timestamp: %s".format([timestamp("2023-02-03T23:31:20+00:00")]) // returns "timestamp: 2023-02-03T23:31:20Z"
// "duration: %s".format([duration("1h45m47s")]) // returns "duration: 6347s"
// "%f".format([3.14]) // returns "3.140000"
// "scientific notation: %e".format([2.71828]) // returns "scientific notation: 2.718280\u202f\u00d7\u202f10\u2070\u2070"
// "5 in binary: %b".format([5]), // returns "5 in binary; 101"
// "26 in hex: %x".format([26]), // returns "26 in hex: 1a"
// "26 in hex (uppercase): %X".format([26]) // returns "26 in hex (uppercase): 1A"
// "30 in octal: %o".format([30]) // returns "30 in octal: 36"
// "a map inside a list: %s".format([[1, 2, 3, {"a": "x", "b": "y", "c": "z"}]]) // returns "a map inside a list: [1, 2, 3, {"a":"x", "b":"y", "c":"d"}]"
// "true bool: %s - false bool: %s\nbinary bool: %b".format([true, false, true]) // returns "true bool: true - false bool: false\nbinary bool: 1"
//
// Passing an incorrect type (an integer to `%s`) is considered an error, as well as attempting
// to use more formatting clauses than there are arguments (`%d %d %d` while passing two ints, for instance).
// If compile-time checking is enabled, and the formatting string is a constant, and the argument list is a literal,
// then letting any arguments go unused/unformatted is also considered an error.
//
// # IndexOf
//
// Returns the integer index of the first occurrence of the search string. If the search string is
// not found the function returns -1.
//
// The function also accepts an optional position from which to begin the substring search. If the
// substring is the empty string, the index where the search starts is returned (zero or custom).
//
// <string>.indexOf(<string>) -> <int>
// <string>.indexOf(<string>, <int>) -> <int>
//
// Examples:
//
// 'hello mellow'.indexOf('') // returns 0
// 'hello mellow'.indexOf('ello') // returns 1
// 'hello mellow'.indexOf('jello') // returns -1
// 'hello mellow'.indexOf('', 2) // returns 2
// 'hello mellow'.indexOf('ello', 2) // returns 7
// 'hello mellow'.indexOf('ello', 20) // error
//
// # Join
//
// Returns a new string where the elements of string list are concatenated.
//
// The function also accepts an optional separator which is placed between elements in the resulting string.
//
// <list<string>>.join() -> <string>
// <list<string>>.join(<string>) -> <string>
//
// Examples:
//
// ['hello', 'mellow'].join() // returns 'hellomellow'
// ['hello', 'mellow'].join(' ') // returns 'hello mellow'
// [].join() // returns ''
// [].join('/') // returns ''
//
// # LastIndexOf
//
// Returns the integer index at the start of the last occurrence of the search string. If the
// search string is not found the function returns -1.
//
// The function also accepts an optional position which represents the last index to be
// considered as the beginning of the substring match. If the substring is the empty string,
// the index where the search starts is returned (string length or custom).
//
// <string>.lastIndexOf(<string>) -> <int>
// <string>.lastIndexOf(<string>, <int>) -> <int>
//
// Examples:
//
// 'hello mellow'.lastIndexOf('') // returns 12
// 'hello mellow'.lastIndexOf('ello') // returns 7
// 'hello mellow'.lastIndexOf('jello') // returns -1
// 'hello mellow'.lastIndexOf('ello', 6) // returns 1
// 'hello mellow'.lastIndexOf('ello', -1) // error
//
// # LowerAscii
//
// Returns a new string where all ASCII characters are lower-cased.
//
// This function does not perform Unicode case-mapping for characters outside the ASCII range.
//
// <string>.lowerAscii() -> <string>
//
// Examples:
//
// 'TacoCat'.lowerAscii() // returns 'tacocat'
// 'TacoCÆt Xii'.lowerAscii() // returns 'tacocÆt xii'
//
// # Strings.Quote
//
// Introduced in version: 1
//
// Takes the given string and makes it safe to print (without any formatting due to escape sequences).
// If any invalid UTF-8 characters are encountered, they are replaced with \uFFFD.
//
// strings.quote(<string>)
//
// Examples:
//
// strings.quote('single-quote with "double quote"') // returns '"single-quote with \"double quote\""'
// strings.quote("two escape sequences \a\n") // returns '"two escape sequences \\a\\n"'
//
// # Replace
//
// Returns a new string based on the target, which replaces the occurrences of a search string
// with a replacement string if present. The function accepts an optional limit on the number of
// substring replacements to be made.
//
// When the replacement limit is 0, the result is the original string. When the limit is a negative
// number, the function behaves the same as replace all.
//
// <string>.replace(<string>, <string>) -> <string>
// <string>.replace(<string>, <string>, <int>) -> <string>
//
// Examples:
//
// 'hello hello'.replace('he', 'we') // returns 'wello wello'
// 'hello hello'.replace('he', 'we', -1) // returns 'wello wello'
// 'hello hello'.replace('he', 'we', 1) // returns 'wello hello'
// 'hello hello'.replace('he', 'we', 0) // returns 'hello hello'
//
// # Split
//
// Returns a list of strings split from the input by the given separator. The function accepts
// an optional argument specifying a limit on the number of substrings produced by the split.
//
// When the split limit is 0, the result is an empty list. When the limit is 1, the result is the
// target string to split. When the limit is a negative number, the function behaves the same as
// split all.
//
// <string>.split(<string>) -> <list<string>>
// <string>.split(<string>, <int>) -> <list<string>>
//
// Examples:
//
// 'hello hello hello'.split(' ') // returns ['hello', 'hello', 'hello']
// 'hello hello hello'.split(' ', 0) // returns []
// 'hello hello hello'.split(' ', 1) // returns ['hello hello hello']
// 'hello hello hello'.split(' ', 2) // returns ['hello', 'hello hello']
// 'hello hello hello'.split(' ', -1) // returns ['hello', 'hello', 'hello']
//
// # Substring
//
// Returns the substring given a numeric range corresponding to character positions. Optionally
// may omit the trailing range for a substring from a given character position until the end of
// a string.
//
// Character offsets are 0-based with an inclusive start range and exclusive end range. It is an
// error to specify an end range that is lower than the start range, or for either the start or end
// index to be negative or exceed the string length.
//
// <string>.substring(<int>) -> <string>
// <string>.substring(<int>, <int>) -> <string>
//
// Examples:
//
// 'tacocat'.substring(4) // returns 'cat'
// 'tacocat'.substring(0, 4) // returns 'taco'
// 'tacocat'.substring(-1) // error
// 'tacocat'.substring(2, 1) // error
//
// # Trim
//
// Returns a new string which removes the leading and trailing whitespace in the target string.
// The trim function uses the Unicode definition of whitespace which does not include the
// zero-width spaces. See: https://en.wikipedia.org/wiki/Whitespace_character#Unicode
//
// <string>.trim() -> <string>
//
// Examples:
//
// ' \ttrim\n '.trim() // returns 'trim'
//
// # UpperAscii
//
// Returns a new string where all ASCII characters are upper-cased.
//
// This function does not perform Unicode case-mapping for characters outside the ASCII range.
//
// <string>.upperAscii() -> <string>
//
// Examples:
//
// 'TacoCat'.upperAscii() // returns 'TACOCAT'
// 'TacoCÆt Xii'.upperAscii() // returns 'TACOCÆT XII'
func Strings(options ...StringsOption) cel.EnvOption {
s := &stringLib{version: math.MaxUint32}
for _, o := range options {
s = o(s)
}
return cel.Lib(s)
}
type stringLib struct {
locale string
version uint32
}
// LibraryName implements the SingletonLibrary interface method.
func (*stringLib) LibraryName() string {
return "cel.lib.ext.strings"
}
// StringsOption is a functional interface for configuring the strings library.
type StringsOption func(*stringLib) *stringLib
// StringsLocale configures the library with the given locale. The locale tag will
// be checked for validity at the time that EnvOptions are configured. If this option
// is not passed, string.format will behave as if en_US was passed as the locale.
func StringsLocale(locale string) StringsOption {
return func(sl *stringLib) *stringLib {
sl.locale = locale
return sl
}
}
// StringsVersion configures the version of the string library.
//
// The version limits which functions are available. Only functions introduced
// below or equal to the given version included in the library. If this option
// is not set, all functions are available.
//
// See the library documentation to determine which version a function was introduced.
// If the documentation does not state which version a function was introduced, it can
// be assumed to be introduced at version 0, when the library was first created.
func StringsVersion(version uint32) StringsOption {
return func(lib *stringLib) *stringLib {
lib.version = version
return lib
}
}
// CompileOptions implements the Library interface method.
func (lib *stringLib) CompileOptions() []cel.EnvOption {
formatLocale := "en_US"
if lib.locale != "" {
// ensure locale is properly-formed if set
_, err := language.Parse(lib.locale)
if err != nil {
return []cel.EnvOption{
func(e *cel.Env) (*cel.Env, error) {
return nil, fmt.Errorf("failed to parse locale: %w", err)
},
}
}
formatLocale = lib.locale
}
opts := []cel.EnvOption{
cel.Function("charAt",
cel.MemberOverload("string_char_at_int", []*cel.Type{cel.StringType, cel.IntType}, cel.StringType,
cel.BinaryBinding(func(str, ind ref.Val) ref.Val {
s := str.(types.String)
i := ind.(types.Int)
return stringOrError(charAt(string(s), int64(i)))
}))),
cel.Function("indexOf",
cel.MemberOverload("string_index_of_string", []*cel.Type{cel.StringType, cel.StringType}, cel.IntType,
cel.BinaryBinding(func(str, substr ref.Val) ref.Val {
s := str.(types.String)
sub := substr.(types.String)
return intOrError(indexOf(string(s), string(sub)))
})),
cel.MemberOverload("string_index_of_string_int", []*cel.Type{cel.StringType, cel.StringType, cel.IntType}, cel.IntType,
cel.FunctionBinding(func(args ...ref.Val) ref.Val {
s := args[0].(types.String)
sub := args[1].(types.String)
offset := args[2].(types.Int)
return intOrError(indexOfOffset(string(s), string(sub), int64(offset)))
}))),
cel.Function("lastIndexOf",
cel.MemberOverload("string_last_index_of_string", []*cel.Type{cel.StringType, cel.StringType}, cel.IntType,
cel.BinaryBinding(func(str, substr ref.Val) ref.Val {
s := str.(types.String)
sub := substr.(types.String)
return intOrError(lastIndexOf(string(s), string(sub)))
})),
cel.MemberOverload("string_last_index_of_string_int", []*cel.Type{cel.StringType, cel.StringType, cel.IntType}, cel.IntType,
cel.FunctionBinding(func(args ...ref.Val) ref.Val {
s := args[0].(types.String)
sub := args[1].(types.String)
offset := args[2].(types.Int)
return intOrError(lastIndexOfOffset(string(s), string(sub), int64(offset)))
}))),
cel.Function("lowerAscii",
cel.MemberOverload("string_lower_ascii", []*cel.Type{cel.StringType}, cel.StringType,
cel.UnaryBinding(func(str ref.Val) ref.Val {
s := str.(types.String)
return stringOrError(lowerASCII(string(s)))
}))),
cel.Function("replace",
cel.MemberOverload(
"string_replace_string_string", []*cel.Type{cel.StringType, cel.StringType, cel.StringType}, cel.StringType,
cel.FunctionBinding(func(args ...ref.Val) ref.Val {
str := args[0].(types.String)
old := args[1].(types.String)
new := args[2].(types.String)
return stringOrError(replace(string(str), string(old), string(new)))
})),
cel.MemberOverload(
"string_replace_string_string_int", []*cel.Type{cel.StringType, cel.StringType, cel.StringType, cel.IntType}, cel.StringType,
cel.FunctionBinding(func(args ...ref.Val) ref.Val {
str := args[0].(types.String)
old := args[1].(types.String)
new := args[2].(types.String)
n := args[3].(types.Int)
return stringOrError(replaceN(string(str), string(old), string(new), int64(n)))
}))),
cel.Function("split",
cel.MemberOverload("string_split_string", []*cel.Type{cel.StringType, cel.StringType}, cel.ListType(cel.StringType),
cel.BinaryBinding(func(str, separator ref.Val) ref.Val {
s := str.(types.String)
sep := separator.(types.String)
return listStringOrError(split(string(s), string(sep)))
})),
cel.MemberOverload("string_split_string_int", []*cel.Type{cel.StringType, cel.StringType, cel.IntType}, cel.ListType(cel.StringType),
cel.FunctionBinding(func(args ...ref.Val) ref.Val {
s := args[0].(types.String)
sep := args[1].(types.String)
n := args[2].(types.Int)
return listStringOrError(splitN(string(s), string(sep), int64(n)))
}))),
cel.Function("substring",
cel.MemberOverload("string_substring_int", []*cel.Type{cel.StringType, cel.IntType}, cel.StringType,
cel.BinaryBinding(func(str, offset ref.Val) ref.Val {
s := str.(types.String)
off := offset.(types.Int)
return stringOrError(substr(string(s), int64(off)))
})),
cel.MemberOverload("string_substring_int_int", []*cel.Type{cel.StringType, cel.IntType, cel.IntType}, cel.StringType,
cel.FunctionBinding(func(args ...ref.Val) ref.Val {
s := args[0].(types.String)
start := args[1].(types.Int)
end := args[2].(types.Int)
return stringOrError(substrRange(string(s), int64(start), int64(end)))
}))),
cel.Function("trim",
cel.MemberOverload("string_trim", []*cel.Type{cel.StringType}, cel.StringType,
cel.UnaryBinding(func(str ref.Val) ref.Val {
s := str.(types.String)
return stringOrError(trimSpace(string(s)))
}))),
cel.Function("upperAscii",
cel.MemberOverload("string_upper_ascii", []*cel.Type{cel.StringType}, cel.StringType,
cel.UnaryBinding(func(str ref.Val) ref.Val {
s := str.(types.String)
return stringOrError(upperASCII(string(s)))
}))),
}
if lib.version >= 1 {
opts = append(opts, cel.Function("format",
cel.MemberOverload("string_format", []*cel.Type{cel.StringType, cel.ListType(cel.DynType)}, cel.StringType,
cel.FunctionBinding(func(args ...ref.Val) ref.Val {
s := string(args[0].(types.String))
formatArgs := args[1].(traits.Lister)
return stringOrError(interpreter.ParseFormatString(s, &stringFormatter{}, &stringArgList{formatArgs}, formatLocale))
}))),
cel.Function("strings.quote", cel.Overload("strings_quote", []*cel.Type{cel.StringType}, cel.StringType,
cel.UnaryBinding(func(str ref.Val) ref.Val {
s := str.(types.String)
return stringOrError(quote(string(s)))
}))))
}
if lib.version >= 2 {
opts = append(opts,
cel.Function("join",
cel.MemberOverload("list_join", []*cel.Type{cel.ListType(cel.StringType)}, cel.StringType,
cel.UnaryBinding(func(list ref.Val) ref.Val {
l := list.(traits.Lister)
return stringOrError(joinValSeparator(l, ""))
})),
cel.MemberOverload("list_join_string", []*cel.Type{cel.ListType(cel.StringType), cel.StringType}, cel.StringType,
cel.BinaryBinding(func(list, delim ref.Val) ref.Val {
l := list.(traits.Lister)
d := delim.(types.String)
return stringOrError(joinValSeparator(l, string(d)))
}))),
)
} else {
opts = append(opts,
cel.Function("join",
cel.MemberOverload("list_join", []*cel.Type{cel.ListType(cel.StringType)}, cel.StringType,
cel.UnaryBinding(func(list ref.Val) ref.Val {
l, err := list.ConvertToNative(stringListType)
if err != nil {
return types.NewErr(err.Error())
}
return stringOrError(join(l.([]string)))
})),
cel.MemberOverload("list_join_string", []*cel.Type{cel.ListType(cel.StringType), cel.StringType}, cel.StringType,
cel.BinaryBinding(func(list, delim ref.Val) ref.Val {
l, err := list.ConvertToNative(stringListType)
if err != nil {
return types.NewErr(err.Error())
}
d := delim.(types.String)
return stringOrError(joinSeparator(l.([]string), string(d)))
}))),
)
}
return opts
}
// ProgramOptions implements the Library interface method.
func (*stringLib) ProgramOptions() []cel.ProgramOption {
return []cel.ProgramOption{}
}
func charAt(str string, ind int64) (string, error) {
i := int(ind)
runes := []rune(str)
if i < 0 || i > len(runes) {
return "", fmt.Errorf("index out of range: %d", ind)
}
if i == len(runes) {
return "", nil
}
return string(runes[i]), nil
}
func indexOf(str, substr string) (int64, error) {
return indexOfOffset(str, substr, int64(0))
}
func indexOfOffset(str, substr string, offset int64) (int64, error) {
if substr == "" {
return offset, nil
}
off := int(offset)
runes := []rune(str)
subrunes := []rune(substr)
if off < 0 || off >= len(runes) {
return -1, fmt.Errorf("index out of range: %d", off)
}
for i := off; i < len(runes)-(len(subrunes)-1); i++ {
found := true
for j := 0; j < len(subrunes); j++ {
if runes[i+j] != subrunes[j] {
found = false
break
}
}
if found {
return int64(i), nil
}
}
return -1, nil
}
func lastIndexOf(str, substr string) (int64, error) {
runes := []rune(str)
if substr == "" {
return int64(len(runes)), nil
}
return lastIndexOfOffset(str, substr, int64(len(runes)-1))
}
func lastIndexOfOffset(str, substr string, offset int64) (int64, error) {
if substr == "" {
return offset, nil
}
off := int(offset)
runes := []rune(str)
subrunes := []rune(substr)
if off < 0 || off >= len(runes) {
return -1, fmt.Errorf("index out of range: %d", off)
}
if off > len(runes)-len(subrunes) {
off = len(runes) - len(subrunes)
}
for i := off; i >= 0; i-- {
found := true
for j := 0; j < len(subrunes); j++ {
if runes[i+j] != subrunes[j] {
found = false
break
}
}
if found {
return int64(i), nil
}
}
return -1, nil
}
func lowerASCII(str string) (string, error) {
runes := []rune(str)
for i, r := range runes {
if r <= unicode.MaxASCII {
r = unicode.ToLower(r)
runes[i] = r
}
}
return string(runes), nil
}
func replace(str, old, new string) (string, error) {
return strings.ReplaceAll(str, old, new), nil
}
func replaceN(str, old, new string, n int64) (string, error) {
return strings.Replace(str, old, new, int(n)), nil
}
func split(str, sep string) ([]string, error) {
return strings.Split(str, sep), nil
}
func splitN(str, sep string, n int64) ([]string, error) {
return strings.SplitN(str, sep, int(n)), nil
}
func substr(str string, start int64) (string, error) {
runes := []rune(str)
if int(start) < 0 || int(start) > len(runes) {
return "", fmt.Errorf("index out of range: %d", start)
}
return string(runes[start:]), nil
}
func substrRange(str string, start, end int64) (string, error) {
runes := []rune(str)
l := len(runes)
if start > end {
return "", fmt.Errorf("invalid substring range. start: %d, end: %d", start, end)
}
if int(start) < 0 || int(start) > l {
return "", fmt.Errorf("index out of range: %d", start)
}
if int(end) < 0 || int(end) > l {
return "", fmt.Errorf("index out of range: %d", end)
}
return string(runes[int(start):int(end)]), nil
}
func trimSpace(str string) (string, error) {
return strings.TrimSpace(str), nil
}
func upperASCII(str string) (string, error) {
runes := []rune(str)
for i, r := range runes {
if r <= unicode.MaxASCII {
r = unicode.ToUpper(r)
runes[i] = r
}
}
return string(runes), nil
}
func joinSeparator(strs []string, separator string) (string, error) {
return strings.Join(strs, separator), nil
}
func join(strs []string) (string, error) {
return strings.Join(strs, ""), nil
}
func joinValSeparator(strs traits.Lister, separator string) (string, error) {
sz := strs.Size().(types.Int)
var sb strings.Builder
for i := types.Int(0); i < sz; i++ {
if i != 0 {
sb.WriteString(separator)
}
elem := strs.Get(i)
str, ok := elem.(types.String)
if !ok {
return "", fmt.Errorf("join: invalid input: %v", elem)
}
sb.WriteString(string(str))
}
return sb.String(), nil
}
type clauseImpl func(ref.Val, string) (string, error)
func clauseForType(argType ref.Type) (clauseImpl, error) {
switch argType {
case types.IntType, types.UintType:
return formatDecimal, nil
case types.StringType, types.BytesType, types.BoolType, types.NullType, types.TypeType:
return FormatString, nil
case types.TimestampType, types.DurationType:
// special case to ensure timestamps/durations get printed as CEL literals
return func(arg ref.Val, locale string) (string, error) {
argStrVal := arg.ConvertToType(types.StringType)
argStr := argStrVal.Value().(string)
if arg.Type() == types.TimestampType {
return fmt.Sprintf("timestamp(%q)", argStr), nil
}
if arg.Type() == types.DurationType {
return fmt.Sprintf("duration(%q)", argStr), nil
}
return "", fmt.Errorf("cannot convert argument of type %s to timestamp/duration", arg.Type().TypeName())
}, nil
case types.ListType:
return formatList, nil
case types.MapType:
return formatMap, nil
case types.DoubleType:
// avoid formatFixed so we can output a period as the decimal separator in order
// to always be a valid CEL literal
return func(arg ref.Val, locale string) (string, error) {
argDouble, ok := arg.Value().(float64)
if !ok {
return "", fmt.Errorf("couldn't convert %s to float64", arg.Type().TypeName())
}
fmtStr := fmt.Sprintf("%%.%df", defaultPrecision)
return fmt.Sprintf(fmtStr, argDouble), nil
}, nil
case types.TypeType:
return func(arg ref.Val, locale string) (string, error) {
return fmt.Sprintf("type(%s)", arg.Value().(string)), nil
}, nil
default:
return nil, fmt.Errorf("no formatting function for %s", argType.TypeName())
}
}
func formatList(arg ref.Val, locale string) (string, error) {
argList := arg.(traits.Lister)
argIterator := argList.Iterator()
var listStrBuilder strings.Builder
_, err := listStrBuilder.WriteRune('[')
if err != nil {
return "", fmt.Errorf("error writing to list string: %w", err)
}
for argIterator.HasNext() == types.True {
member := argIterator.Next()
memberFormat, err := clauseForType(member.Type())
if err != nil {
return "", err
}
unquotedStr, err := memberFormat(member, locale)
if err != nil {
return "", err
}
str := quoteForCEL(member, unquotedStr)
_, err = listStrBuilder.WriteString(str)
if err != nil {
return "", fmt.Errorf("error writing to list string: %w", err)
}
if argIterator.HasNext() == types.True {
_, err = listStrBuilder.WriteString(", ")
if err != nil {
return "", fmt.Errorf("error writing to list string: %w", err)
}
}
}
_, err = listStrBuilder.WriteRune(']')
if err != nil {
return "", fmt.Errorf("error writing to list string: %w", err)
}
return listStrBuilder.String(), nil
}
func formatMap(arg ref.Val, locale string) (string, error) {
argMap := arg.(traits.Mapper)
argIterator := argMap.Iterator()
type mapPair struct {
key string
value string
}
argPairs := make([]mapPair, argMap.Size().Value().(int64))
i := 0
for argIterator.HasNext() == types.True {
key := argIterator.Next()
var keyFormat clauseImpl
switch key.Type() {
case types.StringType, types.BoolType:
keyFormat = FormatString
case types.IntType, types.UintType:
keyFormat = formatDecimal
default:
return "", fmt.Errorf("no formatting function for map key of type %s", key.Type().TypeName())
}
unquotedKeyStr, err := keyFormat(key, locale)
if err != nil {
return "", err
}
keyStr := quoteForCEL(key, unquotedKeyStr)
value, found := argMap.Find(key)
if !found {
return "", fmt.Errorf("could not find key: %q", key)
}
valueFormat, err := clauseForType(value.Type())
if err != nil {
return "", err
}
unquotedValueStr, err := valueFormat(value, locale)
if err != nil {
return "", err
}
valueStr := quoteForCEL(value, unquotedValueStr)
argPairs[i] = mapPair{keyStr, valueStr}
i++
}
sort.SliceStable(argPairs, func(x, y int) bool {
return argPairs[x].key < argPairs[y].key
})
var mapStrBuilder strings.Builder
_, err := mapStrBuilder.WriteRune('{')
if err != nil {
return "", fmt.Errorf("error writing to map string: %w", err)
}
for i, entry := range argPairs {
_, err = mapStrBuilder.WriteString(fmt.Sprintf("%s:%s", entry.key, entry.value))
if err != nil {
return "", fmt.Errorf("error writing to map string: %w", err)
}
if i < len(argPairs)-1 {
_, err = mapStrBuilder.WriteString(", ")
if err != nil {
return "", fmt.Errorf("error writing to map string: %w", err)
}
}
}
_, err = mapStrBuilder.WriteRune('}')
if err != nil {
return "", fmt.Errorf("error writing to map string: %w", err)
}
return mapStrBuilder.String(), nil
}
// quoteForCEL takes a formatted, unquoted value and quotes it in a manner
// suitable for embedding directly in CEL.
func quoteForCEL(refVal ref.Val, unquotedValue string) string {
switch refVal.Type() {
case types.StringType:
return fmt.Sprintf("%q", unquotedValue)
case types.BytesType:
return fmt.Sprintf("b%q", unquotedValue)
case types.DoubleType:
// special case to handle infinity/NaN
num := refVal.Value().(float64)
if math.IsInf(num, 1) || math.IsInf(num, -1) || math.IsNaN(num) {
return fmt.Sprintf("%q", unquotedValue)
}
return unquotedValue
default:
return unquotedValue
}
}
// FormatString returns the string representation of a CEL value.
// It is used to implement the %s specifier in the (string).format() extension
// function.
func FormatString(arg ref.Val, locale string) (string, error) {
switch arg.Type() {
case types.ListType:
return formatList(arg, locale)
case types.MapType:
return formatMap(arg, locale)
case types.IntType, types.UintType, types.DoubleType,
types.BoolType, types.StringType, types.TimestampType, types.BytesType, types.DurationType, types.TypeType:
argStrVal := arg.ConvertToType(types.StringType)
argStr, ok := argStrVal.Value().(string)
if !ok {
return "", fmt.Errorf("could not convert argument %q to string", argStrVal)
}
return argStr, nil
case types.NullType:
return "null", nil
default:
return "", fmt.Errorf("string clause can only be used on strings, bools, bytes, ints, doubles, maps, lists, types, durations, and timestamps, was given %s", arg.Type().TypeName())
}
}
func formatDecimal(arg ref.Val, locale string) (string, error) {
switch arg.Type() {
case types.IntType:
argInt, ok := arg.ConvertToType(types.IntType).Value().(int64)
if !ok {
return "", fmt.Errorf("could not convert \"%s\" to int64", arg.Value())
}
return fmt.Sprintf("%d", argInt), nil
case types.UintType:
argInt, ok := arg.ConvertToType(types.UintType).Value().(uint64)
if !ok {
return "", fmt.Errorf("could not convert \"%s\" to uint64", arg.Value())
}
return fmt.Sprintf("%d", argInt), nil
default:
return "", fmt.Errorf("decimal clause can only be used on integers, was given %s", arg.Type().TypeName())
}
}
func matchLanguage(locale string) (language.Tag, error) {
matcher, err := makeMatcher(locale)
if err != nil {
return language.Und, err
}
tag, _ := language.MatchStrings(matcher, locale)
return tag, nil
}
func makeMatcher(locale string) (language.Matcher, error) {
tags := make([]language.Tag, 0)
tag, err := language.Parse(locale)
if err != nil {
return nil, err
}
tags = append(tags, tag)
return language.NewMatcher(tags), nil
}
// quote implements a string quoting function. The string will be wrapped in
// double quotes, and all valid CEL escape sequences will be escaped to show up
// literally if printed. If the input contains any invalid UTF-8, the invalid runes
// will be replaced with utf8.RuneError.
func quote(s string) (string, error) {
var quotedStrBuilder strings.Builder
for _, c := range sanitize(s) {
switch c {
case '\a':
quotedStrBuilder.WriteString("\\a")
case '\b':
quotedStrBuilder.WriteString("\\b")
case '\f':
quotedStrBuilder.WriteString("\\f")
case '\n':
quotedStrBuilder.WriteString("\\n")
case '\r':
quotedStrBuilder.WriteString("\\r")
case '\t':
quotedStrBuilder.WriteString("\\t")
case '\v':
quotedStrBuilder.WriteString("\\v")
case '\\':
quotedStrBuilder.WriteString("\\\\")
case '"':
quotedStrBuilder.WriteString("\\\"")
default:
quotedStrBuilder.WriteRune(c)
}
}
escapedStr := quotedStrBuilder.String()
return "\"" + escapedStr + "\"", nil
}
// sanitize replaces all invalid runes in the given string with utf8.RuneError.
func sanitize(s string) string {
var sanitizedStringBuilder strings.Builder
for _, r := range s {
if !utf8.ValidRune(r) {
sanitizedStringBuilder.WriteRune(utf8.RuneError)
} else {
sanitizedStringBuilder.WriteRune(r)
}
}
return sanitizedStringBuilder.String()
}
type stringFormatter struct{}
func (c *stringFormatter) String(arg ref.Val, locale string) (string, error) {
return FormatString(arg, locale)
}
func (c *stringFormatter) Decimal(arg ref.Val, locale string) (string, error) {
return formatDecimal(arg, locale)
}
func (c *stringFormatter) Fixed(precision *int) func(ref.Val, string) (string, error) {
if precision == nil {
precision = new(int)
*precision = defaultPrecision
}
return func(arg ref.Val, locale string) (string, error) {
strException := false
if arg.Type() == types.StringType {
argStr := arg.Value().(string)
if argStr == "NaN" || argStr == "Infinity" || argStr == "-Infinity" {
strException = true
}
}
if arg.Type() != types.DoubleType && !strException {
return "", fmt.Errorf("fixed-point clause can only be used on doubles, was given %s", arg.Type().TypeName())
}
argFloatVal := arg.ConvertToType(types.DoubleType)
argFloat, ok := argFloatVal.Value().(float64)
if !ok {
return "", fmt.Errorf("could not convert \"%s\" to float64", argFloatVal.Value())
}
fmtStr := fmt.Sprintf("%%.%df", *precision)
matchedLocale, err := matchLanguage(locale)
if err != nil {
return "", fmt.Errorf("error matching locale: %w", err)
}
return message.NewPrinter(matchedLocale).Sprintf(fmtStr, argFloat), nil
}
}
func (c *stringFormatter) Scientific(precision *int) func(ref.Val, string) (string, error) {
if precision == nil {
precision = new(int)
*precision = defaultPrecision
}
return func(arg ref.Val, locale string) (string, error) {
strException := false
if arg.Type() == types.StringType {
argStr := arg.Value().(string)
if argStr == "NaN" || argStr == "Infinity" || argStr == "-Infinity" {
strException = true
}
}
if arg.Type() != types.DoubleType && !strException {
return "", fmt.Errorf("scientific clause can only be used on doubles, was given %s", arg.Type().TypeName())
}
argFloatVal := arg.ConvertToType(types.DoubleType)
argFloat, ok := argFloatVal.Value().(float64)
if !ok {
return "", fmt.Errorf("could not convert \"%s\" to float64", argFloatVal.Value())
}
matchedLocale, err := matchLanguage(locale)
if err != nil {
return "", fmt.Errorf("error matching locale: %w", err)
}
fmtStr := fmt.Sprintf("%%%de", *precision)
return message.NewPrinter(matchedLocale).Sprintf(fmtStr, argFloat), nil
}
}
func (c *stringFormatter) Binary(arg ref.Val, locale string) (string, error) {
switch arg.Type() {
case types.IntType:
argInt := arg.Value().(int64)
// locale is intentionally unused as integers formatted as binary
// strings are locale-independent
return fmt.Sprintf("%b", argInt), nil
case types.UintType:
argInt := arg.Value().(uint64)
return fmt.Sprintf("%b", argInt), nil
case types.BoolType:
argBool := arg.Value().(bool)
if argBool {
return "1", nil
}
return "0", nil
default:
return "", fmt.Errorf("only integers and bools can be formatted as binary, was given %s", arg.Type().TypeName())
}
}
func (c *stringFormatter) Hex(useUpper bool) func(ref.Val, string) (string, error) {
return func(arg ref.Val, locale string) (string, error) {
fmtStr := "%x"
if useUpper {
fmtStr = "%X"
}
switch arg.Type() {
case types.StringType, types.BytesType:
if arg.Type() == types.BytesType {
return fmt.Sprintf(fmtStr, arg.Value().([]byte)), nil
}
return fmt.Sprintf(fmtStr, arg.Value().(string)), nil
case types.IntType:
argInt, ok := arg.Value().(int64)
if !ok {
return "", fmt.Errorf("could not convert \"%s\" to int64", arg.Value())
}
return fmt.Sprintf(fmtStr, argInt), nil
case types.UintType:
argInt, ok := arg.Value().(uint64)
if !ok {
return "", fmt.Errorf("could not convert \"%s\" to uint64", arg.Value())
}
return fmt.Sprintf(fmtStr, argInt), nil
default:
return "", fmt.Errorf("only integers, byte buffers, and strings can be formatted as hex, was given %s", arg.Type().TypeName())
}
}
}
func (c *stringFormatter) Octal(arg ref.Val, locale string) (string, error) {
switch arg.Type() {
case types.IntType:
argInt := arg.Value().(int64)
return fmt.Sprintf("%o", argInt), nil
case types.UintType:
argInt := arg.Value().(uint64)
return fmt.Sprintf("%o", argInt), nil
default:
return "", fmt.Errorf("octal clause can only be used on integers, was given %s", arg.Type().TypeName())
}
}
type stringArgList struct {
args traits.Lister
}
func (c *stringArgList) Arg(index int64) (ref.Val, error) {
if index >= c.args.Size().Value().(int64) {
return nil, fmt.Errorf("index %d out of range", index)
}
return c.args.Get(types.Int(index)), nil
}
func (c *stringArgList) ArgSize() int64 {
return c.args.Size().Value().(int64)
}
var (
stringListType = reflect.TypeOf([]string{})
)