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Diffstat (limited to 'vendor/google.golang.org/protobuf/internal/strs/strings.go')
-rw-r--r-- | vendor/google.golang.org/protobuf/internal/strs/strings.go | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/vendor/google.golang.org/protobuf/internal/strs/strings.go b/vendor/google.golang.org/protobuf/internal/strs/strings.go new file mode 100644 index 000000000..0b74e7658 --- /dev/null +++ b/vendor/google.golang.org/protobuf/internal/strs/strings.go @@ -0,0 +1,196 @@ +// Copyright 2019 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package strs provides string manipulation functionality specific to protobuf. +package strs + +import ( + "go/token" + "strings" + "unicode" + "unicode/utf8" + + "google.golang.org/protobuf/internal/flags" + "google.golang.org/protobuf/reflect/protoreflect" +) + +// EnforceUTF8 reports whether to enforce strict UTF-8 validation. +func EnforceUTF8(fd protoreflect.FieldDescriptor) bool { + if flags.ProtoLegacy { + if fd, ok := fd.(interface{ EnforceUTF8() bool }); ok { + return fd.EnforceUTF8() + } + } + return fd.Syntax() == protoreflect.Proto3 +} + +// GoCamelCase camel-cases a protobuf name for use as a Go identifier. +// +// If there is an interior underscore followed by a lower case letter, +// drop the underscore and convert the letter to upper case. +func GoCamelCase(s string) string { + // Invariant: if the next letter is lower case, it must be converted + // to upper case. + // That is, we process a word at a time, where words are marked by _ or + // upper case letter. Digits are treated as words. + var b []byte + for i := 0; i < len(s); i++ { + c := s[i] + switch { + case c == '.' && i+1 < len(s) && isASCIILower(s[i+1]): + // Skip over '.' in ".{{lowercase}}". + case c == '.': + b = append(b, '_') // convert '.' to '_' + case c == '_' && (i == 0 || s[i-1] == '.'): + // Convert initial '_' to ensure we start with a capital letter. + // Do the same for '_' after '.' to match historic behavior. + b = append(b, 'X') // convert '_' to 'X' + case c == '_' && i+1 < len(s) && isASCIILower(s[i+1]): + // Skip over '_' in "_{{lowercase}}". + case isASCIIDigit(c): + b = append(b, c) + default: + // Assume we have a letter now - if not, it's a bogus identifier. + // The next word is a sequence of characters that must start upper case. + if isASCIILower(c) { + c -= 'a' - 'A' // convert lowercase to uppercase + } + b = append(b, c) + + // Accept lower case sequence that follows. + for ; i+1 < len(s) && isASCIILower(s[i+1]); i++ { + b = append(b, s[i+1]) + } + } + } + return string(b) +} + +// GoSanitized converts a string to a valid Go identifier. +func GoSanitized(s string) string { + // Sanitize the input to the set of valid characters, + // which must be '_' or be in the Unicode L or N categories. + s = strings.Map(func(r rune) rune { + if unicode.IsLetter(r) || unicode.IsDigit(r) { + return r + } + return '_' + }, s) + + // Prepend '_' in the event of a Go keyword conflict or if + // the identifier is invalid (does not start in the Unicode L category). + r, _ := utf8.DecodeRuneInString(s) + if token.Lookup(s).IsKeyword() || !unicode.IsLetter(r) { + return "_" + s + } + return s +} + +// JSONCamelCase converts a snake_case identifier to a camelCase identifier, +// according to the protobuf JSON specification. +func JSONCamelCase(s string) string { + var b []byte + var wasUnderscore bool + for i := 0; i < len(s); i++ { // proto identifiers are always ASCII + c := s[i] + if c != '_' { + if wasUnderscore && isASCIILower(c) { + c -= 'a' - 'A' // convert to uppercase + } + b = append(b, c) + } + wasUnderscore = c == '_' + } + return string(b) +} + +// JSONSnakeCase converts a camelCase identifier to a snake_case identifier, +// according to the protobuf JSON specification. +func JSONSnakeCase(s string) string { + var b []byte + for i := 0; i < len(s); i++ { // proto identifiers are always ASCII + c := s[i] + if isASCIIUpper(c) { + b = append(b, '_') + c += 'a' - 'A' // convert to lowercase + } + b = append(b, c) + } + return string(b) +} + +// MapEntryName derives the name of the map entry message given the field name. +// See protoc v3.8.0: src/google/protobuf/descriptor.cc:254-276,6057 +func MapEntryName(s string) string { + var b []byte + upperNext := true + for _, c := range s { + switch { + case c == '_': + upperNext = true + case upperNext: + b = append(b, byte(unicode.ToUpper(c))) + upperNext = false + default: + b = append(b, byte(c)) + } + } + b = append(b, "Entry"...) + return string(b) +} + +// EnumValueName derives the camel-cased enum value name. +// See protoc v3.8.0: src/google/protobuf/descriptor.cc:297-313 +func EnumValueName(s string) string { + var b []byte + upperNext := true + for _, c := range s { + switch { + case c == '_': + upperNext = true + case upperNext: + b = append(b, byte(unicode.ToUpper(c))) + upperNext = false + default: + b = append(b, byte(unicode.ToLower(c))) + upperNext = false + } + } + return string(b) +} + +// TrimEnumPrefix trims the enum name prefix from an enum value name, +// where the prefix is all lowercase without underscores. +// See protoc v3.8.0: src/google/protobuf/descriptor.cc:330-375 +func TrimEnumPrefix(s, prefix string) string { + s0 := s // original input + for len(s) > 0 && len(prefix) > 0 { + if s[0] == '_' { + s = s[1:] + continue + } + if unicode.ToLower(rune(s[0])) != rune(prefix[0]) { + return s0 // no prefix match + } + s, prefix = s[1:], prefix[1:] + } + if len(prefix) > 0 { + return s0 // no prefix match + } + s = strings.TrimLeft(s, "_") + if len(s) == 0 { + return s0 // avoid returning empty string + } + return s +} + +func isASCIILower(c byte) bool { + return 'a' <= c && c <= 'z' +} +func isASCIIUpper(c byte) bool { + return 'A' <= c && c <= 'Z' +} +func isASCIIDigit(c byte) bool { + return '0' <= c && c <= '9' +} |