| // 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 ( |
| "strings" |
| "unicode" |
| |
| "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.Proto1Legacy { |
| if fd, ok := fd.(interface{ EnforceUTF8() bool }); ok { |
| return fd.EnforceUTF8() |
| } |
| } |
| return fd.Syntax() == protoreflect.Proto3 |
| } |
| |
| // 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 != '_' { |
| isLower := 'a' <= c && c <= 'z' |
| if wasUnderscore && isLower { |
| 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] |
| isUpper := 'A' <= c && c <= 'Z' |
| if isUpper { |
| 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 |
| } |