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[Kotlin] Support for optional scalars. (#6115)

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More information on #6014
This commit is contained in:
Paulo Pinheiro
2020-09-18 08:31:51 +02:00
committed by GitHub
parent e1be8aaadd
commit 6228b66d3d
7 changed files with 463 additions and 31 deletions
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93
src/idl_gen_kotlin.cpp
View File

@@ -159,6 +159,24 @@ class KotlinGenerator : public BaseGenerator {
}
}
// with the addition of optional scalar types,
// we are adding the nullable '?' operator to return type of a field.
std::string GetterReturnType(const FieldDef &field) const {
auto base_type = field.value.type.base_type;
auto r_type = GenTypeGet(field.value.type);
if (field.IsScalarOptional() ||
// string, structs and unions
(base_type == BASE_TYPE_STRING || base_type == BASE_TYPE_STRUCT ||
base_type == BASE_TYPE_UNION) ||
// vector of anything not scalar
(base_type == BASE_TYPE_VECTOR &&
!IsScalar(field.value.type.VectorType().base_type))) {
r_type += "?";
}
return r_type;
}
std::string GenTypeGet(const Type &type) const {
return IsScalar(type.base_type) ? GenTypeBasic(type.base_type)
: GenTypePointer(type);
@@ -179,6 +197,18 @@ class KotlinGenerator : public BaseGenerator {
// - Floats are upcasted to doubles
// - Unsigned are casted to signed
std::string GenFBBDefaultValue(const FieldDef &field) const {
if (field.IsScalarOptional()) {
// although default value is null, java API forces us to present a real
// default value for scalars, while adding a field to the buffer. This is
// not a problem because the default can be representing just by not
// calling builder.addMyField()
switch (field.value.type.base_type) {
case BASE_TYPE_DOUBLE:
case BASE_TYPE_FLOAT: return "0.0";
case BASE_TYPE_BOOL: return "false";
default: return "0";
}
}
auto out = GenDefaultValue(field, true);
// All FlatBufferBuilder default floating point values are doubles
if (field.value.type.base_type == BASE_TYPE_FLOAT) {
@@ -204,6 +234,8 @@ class KotlinGenerator : public BaseGenerator {
bool force_signed = false) const {
auto &value = field.value;
auto base_type = field.value.type.base_type;
if (field.IsScalarOptional()) { return "null"; }
if (IsFloat(base_type)) {
auto val = KotlinFloatGen.GenFloatConstant(field);
if (base_type == BASE_TYPE_DOUBLE && val.back() == 'f') {
@@ -655,19 +687,22 @@ class KotlinGenerator : public BaseGenerator {
CodeWriter &writer, const IDLOptions options) const {
auto field_type = GenTypeBasic(field.value.type.base_type);
auto secondArg = MakeCamel(Esc(field.name), false) + ": " + field_type;
GenerateFunOneLine(writer, "add" + MakeCamel(Esc(field.name), true),
"builder: FlatBufferBuilder, " + secondArg, "", [&]() {
auto method = GenMethod(field.value.type);
writer.SetValue("field_name",
MakeCamel(Esc(field.name), false));
writer.SetValue("method_name", method);
writer.SetValue("pos", field_pos);
writer.SetValue("default", GenFBBDefaultValue(field));
writer.SetValue("cast", GenFBBValueCast(field));
writer += "builder.add{{method_name}}({{pos}}, \\";
writer += "{{field_name}}{{cast}}, {{default}})";
}, options.gen_jvmstatic);
GenerateFunOneLine(
writer, "add" + MakeCamel(Esc(field.name), true),
"builder: FlatBufferBuilder, " + secondArg, "",
[&]() {
auto method = GenMethod(field.value.type);
writer.SetValue("field_name", MakeCamel(Esc(field.name), false));
writer.SetValue("method_name", method);
writer.SetValue("pos", field_pos);
writer.SetValue("default", GenFBBDefaultValue(field));
writer.SetValue("cast", GenFBBValueCast(field));
writer += "builder.add{{method_name}}({{pos}}, \\";
writer += "{{field_name}}{{cast}}, {{default}})";
},
options.gen_jvmstatic);
}
static std::string ToSignedType(const Type &type) {
@@ -754,7 +789,8 @@ class KotlinGenerator : public BaseGenerator {
} else {
params << ": ";
}
params << GenTypeBasic(field.value.type.base_type);
auto optional = field.IsScalarOptional() ? "?" : "";
params << GenTypeBasic(field.value.type.base_type) << optional;
}
GenerateFun(writer, name, params.str(), "Int", [&]() {
@@ -773,11 +809,16 @@ class KotlinGenerator : public BaseGenerator {
MakeCamel(Esc(field.name), true));
writer.SetValue("field_name", MakeCamel(Esc(field.name), false));
// we wrap on null check for scalar optionals
writer +=
field.IsScalarOptional() ? "{{field_name}}?.run { \\" : "\\";
writer += "add{{camel_field_name}}(builder, {{field_name}}\\";
if (!IsScalar(field.value.type.base_type)) {
writer += "Offset\\";
}
writer += ")";
// we wrap on null check for scalar optionals
writer += field.IsScalarOptional() ? ") }" : ")";
}
}
}
@@ -812,7 +853,7 @@ class KotlinGenerator : public BaseGenerator {
auto field_name = MakeCamel(Esc(field.name), false);
auto field_type = GenTypeGet(field.value.type);
auto field_default_value = GenDefaultValue(field);
auto return_type = GenTypeGet(field.value.type);
auto return_type = GetterReturnType(field);
auto bbgetter = ByteBufferGetter(field.value.type, "bb");
auto ucast = CastToUsigned(field);
auto offset_val = NumToString(field.value.offset);
@@ -829,14 +870,13 @@ class KotlinGenerator : public BaseGenerator {
writer.SetValue("bbgetter", bbgetter);
writer.SetValue("ucast", ucast);
auto opt_ret_type = return_type + "?";
// Generate the accessors that don't do object reuse.
if (value_base_type == BASE_TYPE_STRUCT) {
// Calls the accessor that takes an accessor object with a
// new object.
// val pos
// get() = pos(Vec3())
GenerateGetterOneLine(writer, field_name, opt_ret_type, [&]() {
GenerateGetterOneLine(writer, field_name, return_type, [&]() {
writer += "{{field_name}}({{field_type}}())";
});
} else if (value_base_type == BASE_TYPE_VECTOR &&
@@ -844,8 +884,8 @@ class KotlinGenerator : public BaseGenerator {
// Accessors for vectors of structs also take accessor objects,
// this generates a variant without that argument.
// ex: fun weapons(j: Int) = weapons(Weapon(), j)
GenerateFunOneLine(writer, field_name, "j: Int", opt_ret_type, [&]() {
writer += "{{field_name}}({{return_type}}(), j)";
GenerateFunOneLine(writer, field_name, "j: Int", return_type, [&]() {
writer += "{{field_name}}({{field_type}}(), j)";
});
}
@@ -872,7 +912,7 @@ class KotlinGenerator : public BaseGenerator {
// fun pos(obj: Vec3) : Vec3? = obj.__assign(bb_pos + 4, bb)
// ? adds nullability annotation
GenerateFunOneLine(
writer, field_name, "obj: " + field_type, return_type + "?",
writer, field_name, "obj: " + field_type, return_type,
[&]() { writer += "obj.__assign(bb_pos + {{offset}}, bb)"; });
} else {
// create getter with object reuse
@@ -887,8 +927,7 @@ class KotlinGenerator : public BaseGenerator {
// }
// ? adds nullability annotation
GenerateFun(
writer, field_name, "obj: " + field_type, return_type + "?",
[&]() {
writer, field_name, "obj: " + field_type, return_type, [&]() {
auto fixed = field.value.type.struct_def->fixed;
writer.SetValue("seek", Indirect("o + bb_pos", fixed));
@@ -908,7 +947,7 @@ class KotlinGenerator : public BaseGenerator {
// return if (o != 0) __string(o + bb_pos) else null
// }
// ? adds nullability annotation
GenerateGetter(writer, field_name, return_type + "?", [&]() {
GenerateGetter(writer, field_name, return_type, [&]() {
writer += "val o = __offset({{offset}})";
writer += "return if (o != 0) __string(o + bb_pos) else null";
});
@@ -926,15 +965,13 @@ class KotlinGenerator : public BaseGenerator {
auto vectortype = field.value.type.VectorType();
std::string params = "j: Int";
std::string nullable = IsScalar(vectortype.base_type) ? "" : "?";
if (vectortype.base_type == BASE_TYPE_STRUCT ||
vectortype.base_type == BASE_TYPE_UNION) {
params = "obj: " + field_type + ", j: Int";
}
auto ret_type = return_type + nullable;
GenerateFun(writer, field_name, params, ret_type, [&]() {
GenerateFun(writer, field_name, params, return_type, [&]() {
auto inline_size = NumToString(InlineSize(vectortype));
auto index = "__vector(o) + j * " + inline_size;
auto not_found = NotFoundReturn(field.value.type.element);
@@ -959,8 +996,8 @@ class KotlinGenerator : public BaseGenerator {
break;
}
case BASE_TYPE_UNION:
GenerateFun(writer, field_name, "obj: " + field_type,
return_type + "?", [&]() {
GenerateFun(writer, field_name, "obj: " + field_type, return_type,
[&]() {
writer += OffsetWrapperOneLine(
offset_val, bbgetter + "(obj, o + bb_pos)",
"null");

3
src/idl_parser.cpp
View File

@@ -2263,7 +2263,8 @@ CheckedError Parser::CheckClash(std::vector<FieldDef *> &fields,
bool Parser::SupportsOptionalScalars() const {
return !(opts.lang_to_generate &
~(IDLOptions::kRust | IDLOptions::kSwift | IDLOptions::kLobster));
~(IDLOptions::kRust | IDLOptions::kSwift | IDLOptions::kLobster |
IDLOptions::kKotlin));
}
bool Parser::SupportsAdvancedUnionFeatures() const {