BigfootDev/flatbuffers
1
0
Fork 1
mirror of https://github.com/google/flatbuffers.git synced 2026-06-17 01:26:45 +00:00
Code Issues Packages Projects Releases Wiki Activity

Enums use native enums in C#

Browse Source 
Enums should not be (badly) emulated with classes in C# but should
use native C# enums instead. Java implementation made an explicit
choice not to use the (more complex) Java enums, but C# enums are
just light-weight syntactic coating over integral types.

Fixes issue #171.

Change-Id: I9f4d6ba5324400a1e52982e49b58603cb7d7cca7
This commit is contained in:
Mormegil
2015-04-13 13:25:03 +02:00
committed by Wouter van Oortmerssen
parent 557c57eb9d
commit e3b432cba8
6 changed files with 129 additions and 91 deletions
Download Patch File Download Diff File Expand all files Collapse all files

170
src/idl_gen_general.cpp
View File

@@ -80,6 +80,8 @@ struct LanguageParameters {
const char *open_curly;
const char *const_decl;
const char *unsubclassable_decl;
const char *enum_decl;
const char *enum_separator;
const char *inheritance_marker;
const char *namespace_ident;
const char *namespace_begin;
@@ -99,6 +101,8 @@ LanguageParameters language_parameters[] = {
" {\n",
" final ",
"final ",
"final class ",
";\n",
" extends ",
"package ",
";",
@@ -121,6 +125,8 @@ LanguageParameters language_parameters[] = {
"\n{\n",
" readonly ",
"sealed ",
"enum ",
",\n",
" : ",
"namespace ",
"\n{",
@@ -144,6 +150,8 @@ LanguageParameters language_parameters[] = {
"\n{\n",
"const ",
" ",
"class ",
";\n",
"",
"package ",
"",
@@ -181,6 +189,16 @@ static std::string GenTypeBasic(const LanguageParameters &lang,
return gtypename[type.base_type * GeneratorOptions::kMAX + lang.language];
}
// Generate type to be used in user-facing API
static std::string GenTypeForUser(const LanguageParameters &lang,
const Type &type) {
if (lang.language == GeneratorOptions::kCSharp) {
if (type.enum_def != nullptr &&
type.base_type != BASE_TYPE_UNION) return type.enum_def->name;
}
return GenTypeBasic(lang, type);
}
static std::string GenTypeGet(const LanguageParameters &lang,
const Type &type);
@@ -240,17 +258,44 @@ static std::string DestinationMask(const LanguageParameters &lang,
}
}
// Cast necessary to correctly read serialized unsigned values.
// Casts necessary to correctly read serialized data
static std::string DestinationCast(const LanguageParameters &lang,
const Type &type) {
if (lang.language == GeneratorOptions::kJava &&
(type.base_type == BASE_TYPE_UINT ||
(type.base_type == BASE_TYPE_VECTOR &&
type.element == BASE_TYPE_UINT))) return "(long)";
switch (lang.language) {
case GeneratorOptions::kJava:
// Cast necessary to correctly read serialized unsigned values.
if (type.base_type == BASE_TYPE_UINT ||
(type.base_type == BASE_TYPE_VECTOR &&
type.element == BASE_TYPE_UINT)) return "(long)";
break;
case GeneratorOptions::kCSharp:
// Cast from raw integral types to enum
if (type.enum_def != nullptr &&
type.base_type != BASE_TYPE_UNION) return "(" + type.enum_def->name + ")";
break;
default:
break;
}
return "";
}
// Read value and possibly process it to get proper value
static std::string DestinationValue(const LanguageParameters &lang,
const std::string &name,
const Type &type) {
std::string type_mask = DestinationMask(lang, type, false);
// is a typecast needed? (for C# enums and unsigned values in Java)
if (type_mask.length() ||
(lang.language == GeneratorOptions::kCSharp &&
type.enum_def != nullptr &&
type.base_type != BASE_TYPE_UNION)) {
return "(" + GenTypeBasic(lang, type) + ")(" + name + type_mask + ")";
} else {
return name;
}
}
static std::string GenDefaultValue(const Value &value) {
return value.type.base_type == BASE_TYPE_BOOL
@@ -269,50 +314,61 @@ static void GenEnum(const LanguageParameters &lang, EnumDef &enum_def,
// to map directly to how they're used in C/C++ and file formats.
// That, and Java Enums are expensive, and not universally liked.
GenComment(enum_def.doc_comment, code_ptr, &lang.comment_config);
code += std::string("public ") + lang.unsubclassable_decl;
code += "class " + enum_def.name + lang.open_curly;
code += " private " + enum_def.name + "() { }\n";
code += std::string("public ") + lang.enum_decl + enum_def.name;
if (lang.language == GeneratorOptions::kCSharp) {
code += lang.inheritance_marker + GenTypeBasic(lang, enum_def.underlying_type);
}
code += lang.open_curly;
if (lang.language == GeneratorOptions::kJava) {
code += " private " + enum_def.name + "() { }\n";
}
for (auto it = enum_def.vals.vec.begin();
it != enum_def.vals.vec.end();
++it) {
auto &ev = **it;
GenComment(ev.doc_comment, code_ptr, &lang.comment_config, " ");
code += " public static";
code += lang.const_decl;
code += GenTypeBasic(lang, enum_def.underlying_type);
if (lang.language != GeneratorOptions::kCSharp) {
code += " public static";
code += lang.const_decl;
code += GenTypeBasic(lang, enum_def.underlying_type);
}
code += " " + ev.name + " = ";
code += NumToString(ev.value) + ";\n";
code += NumToString(ev.value);
code += lang.enum_separator;
}
// Generate a generate string table for enum values.
// Problem is, if values are very sparse that could generate really big
// tables. Ideally in that case we generate a map lookup instead, but for
// the moment we simply don't output a table at all.
auto range = enum_def.vals.vec.back()->value -
enum_def.vals.vec.front()->value + 1;
// Average distance between values above which we consider a table
// "too sparse". Change at will.
static const int kMaxSparseness = 5;
if (range / static_cast<int64_t>(enum_def.vals.vec.size()) < kMaxSparseness) {
code += "\n private static";
code += lang.const_decl;
code += lang.string_type;
code += "[] names = { ";
auto val = enum_def.vals.vec.front()->value;
for (auto it = enum_def.vals.vec.begin();
it != enum_def.vals.vec.end();
++it) {
while (val++ != (*it)->value) code += "\"\", ";
code += "\"" + (*it)->name + "\", ";
// We do not do that for C# where this functionality is native.
if (lang.language != GeneratorOptions::kCSharp) {
// Problem is, if values are very sparse that could generate really big
// tables. Ideally in that case we generate a map lookup instead, but for
// the moment we simply don't output a table at all.
auto range = enum_def.vals.vec.back()->value -
enum_def.vals.vec.front()->value + 1;
// Average distance between values above which we consider a table
// "too sparse". Change at will.
static const int kMaxSparseness = 5;
if (range / static_cast<int64_t>(enum_def.vals.vec.size()) < kMaxSparseness) {
code += "\n private static";
code += lang.const_decl;
code += lang.string_type;
code += "[] names = { ";
auto val = enum_def.vals.vec.front()->value;
for (auto it = enum_def.vals.vec.begin();
it != enum_def.vals.vec.end();
++it) {
while (val++ != (*it)->value) code += "\"\", ";
code += "\"" + (*it)->name + "\", ";
}
code += "};\n\n";
code += " public static ";
code += lang.string_type;
code += " " + MakeCamel("name", lang.first_camel_upper);
code += "(int e) { return names[e";
if (enum_def.vals.vec.front()->value)
code += " - " + enum_def.vals.vec.front()->name;
code += "]; }\n";
}
code += "};\n\n";
code += " public static ";
code += lang.string_type;
code += " " + MakeCamel("name", lang.first_camel_upper);
code += "(int e) { return names[e";
if (enum_def.vals.vec.front()->value)
code += " - " + enum_def.vals.vec.front()->name;
code += "]; }\n";
}
// Close the class
@@ -364,8 +420,8 @@ static void GenStructArgs(const LanguageParameters &lang,
(field.value.type.struct_def->name + "_").c_str());
} else {
code += ", ";
code += GenTypeBasic(lang,
DestinationType(lang, field.value.type, false));
code += GenTypeForUser(lang,
DestinationType(lang, field.value.type, false));
code += " ";
code += nameprefix;
code += MakeCamel(field.name, lang.first_camel_upper);
@@ -397,13 +453,7 @@ static void GenStructBody(const LanguageParameters &lang,
code += " builder." + FunctionStart(lang, 'P') + "ut";
code += GenMethod(lang, field.value.type) + "(";
auto argname = nameprefix + MakeCamel(field.name, lang.first_camel_upper);
std::string type_mask = DestinationMask(lang, field.value.type, false);
if (type_mask.length()) {
code += "(" + GenTypeBasic(lang, field.value.type) + ")";
code += "(" + argname + type_mask + ")";
} else {
code += argname;
}
code += DestinationValue(lang, argname, field.value.type);
code += ");\n";
}
}
@@ -464,7 +514,11 @@ static void GenStruct(const LanguageParameters &lang, const Parser &parser,
GenComment(field.doc_comment, code_ptr, &lang.comment_config, " ");
std::string type_name = GenTypeGet(lang, field.value.type);
std::string type_name_dest =
GenTypeGet(lang, DestinationType(lang, field.value.type, true));
lang.language == GeneratorOptions::kCSharp &&
field.value.type.enum_def != nullptr &&
field.value.type.base_type != BASE_TYPE_UNION
? field.value.type.enum_def->name
: GenTypeGet(lang, DestinationType(lang, field.value.type, true));
std::string dest_mask = DestinationMask(lang, field.value.type, true);
std::string dest_cast = DestinationCast(lang, field.value.type);
std::string method_start = " public " + type_name_dest + " " +
@@ -612,8 +666,8 @@ static void GenStruct(const LanguageParameters &lang, const Parser &parser,
auto &field = **it;
if (field.deprecated) continue;
code += ",\n ";
code += GenTypeBasic(lang,
DestinationType(lang, field.value.type, false));
code += GenTypeForUser(lang,
DestinationType(lang, field.value.type, false));
code += " ";
code += field.name;
// Java doesn't have defaults, which means this method must always
@@ -661,20 +715,14 @@ static void GenStruct(const LanguageParameters &lang, const Parser &parser,
code += " public static void " + FunctionStart(lang, 'A') + "dd";
code += MakeCamel(field.name);
code += "(FlatBufferBuilder builder, ";
code += GenTypeBasic(lang,
DestinationType(lang, field.value.type, false));
code += GenTypeForUser(lang,
DestinationType(lang, field.value.type, false));
auto argname = MakeCamel(field.name, false);
if (!IsScalar(field.value.type.base_type)) argname += "Offset";
code += " " + argname + ") { builder." + FunctionStart(lang, 'A') + "dd";
code += GenMethod(lang, field.value.type) + "(";
code += NumToString(it - struct_def.fields.vec.begin()) + ", ";
std::string type_mask = DestinationMask(lang, field.value.type, false);
if (type_mask.length()) {
code += "(" + GenTypeBasic(lang, field.value.type) + ")";
code += "(" + argname + type_mask + ")";
} else {
code += argname;
}
code += DestinationValue(lang, argname, field.value.type);
code += ", " + GenDefaultValue(field.value);
code += "); }\n";
if (field.value.type.base_type == BASE_TYPE_VECTOR) {