[Go] Add mutation functions for vector elements (#5221)

Fixes #5206

src/idl_gen_go.cpp

@@ -620,6 +620,27 @@ class GoGenerator : public BaseGenerator {
     code += "}\n\n";
   }
 
+  // Mutate an element of a vector of scalars.
+  void MutateElementOfVectorOfNonStruct(const StructDef &struct_def,
+                                        const FieldDef &field,
+                                        std::string *code_ptr) {
+    std::string &code = *code_ptr;
+    auto vectortype = field.value.type.VectorType();
+    std::string type = MakeCamel(GenTypeBasic(vectortype));
+    std::string setter = "rcv._tab.Mutate" + type;
+    GenReceiver(struct_def, code_ptr);
+    code += " Mutate" + MakeCamel(field.name);
+    code += "(j int, n " + TypeName(field) + ") bool ";
+    code += OffsetPrefix(field);
+    code += "\t\ta := rcv._tab.Vector(o)\n";
+    code += "\t\treturn " + setter + "(";
+    code += "a+flatbuffers.UOffsetT(j*";
+    code += NumToString(InlineSize(vectortype)) + "), n)\n";
+    code += "\t}\n";
+    code += "\treturn false\n";
+    code += "}\n\n";
+  }
+
   // Generate a struct field setter, conditioned on its child type(s).
   void GenStructMutator(const StructDef &struct_def, const FieldDef &field,
                         std::string *code_ptr) {
@@ -630,6 +651,10 @@ class GoGenerator : public BaseGenerator {
       } else {
         MutateScalarFieldOfTable(struct_def, field, code_ptr);
       }
+    } else if (field.value.type.base_type == BASE_TYPE_VECTOR) {
+      if (IsScalar(field.value.type.element)) {
+        MutateElementOfVectorOfNonStruct(struct_def, field, code_ptr);
+      }
     }
   }
 

tests/MyGame/Example/Monster.go

@@ -99,6 +99,15 @@ func (rcv *Monster) InventoryBytes() []byte {
 	return nil
 }
 
+func (rcv *Monster) MutateInventory(j int, n byte) bool {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(14))
+	if o != 0 {
+		a := rcv._tab.Vector(o)
+		return rcv._tab.MutateByte(a+flatbuffers.UOffsetT(j*1), n)
+	}
+	return false
+}
+
 func (rcv *Monster) Color() Color {
 	o := flatbuffers.UOffsetT(rcv._tab.Offset(16))
 	if o != 0 {
@@ -230,6 +239,15 @@ func (rcv *Monster) TestnestedflatbufferBytes() []byte {
 	return nil
 }
 
+func (rcv *Monster) MutateTestnestedflatbuffer(j int, n byte) bool {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(30))
+	if o != 0 {
+		a := rcv._tab.Vector(o)
+		return rcv._tab.MutateByte(a+flatbuffers.UOffsetT(j*1), n)
+	}
+	return false
+}
+
 func (rcv *Monster) Testempty(obj *Stat) *Stat {
 	o := flatbuffers.UOffsetT(rcv._tab.Offset(32))
 	if o != 0 {
@@ -368,6 +386,15 @@ func (rcv *Monster) TestarrayofboolsLength() int {
 	return 0
 }
 
+func (rcv *Monster) MutateTestarrayofbools(j int, n bool) bool {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(52))
+	if o != 0 {
+		a := rcv._tab.Vector(o)
+		return rcv._tab.MutateBool(a+flatbuffers.UOffsetT(j*1), n)
+	}
+	return false
+}
+
 func (rcv *Monster) Testf() float32 {
 	o := flatbuffers.UOffsetT(rcv._tab.Offset(54))
 	if o != 0 {
@@ -465,6 +492,15 @@ func (rcv *Monster) FlexBytes() []byte {
 	return nil
 }
 
+func (rcv *Monster) MutateFlex(j int, n byte) bool {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(64))
+	if o != 0 {
+		a := rcv._tab.Vector(o)
+		return rcv._tab.MutateByte(a+flatbuffers.UOffsetT(j*1), n)
+	}
+	return false
+}
+
 func (rcv *Monster) Test5(obj *Test, j int) bool {
 	o := flatbuffers.UOffsetT(rcv._tab.Offset(66))
 	if o != 0 {
@@ -501,6 +537,15 @@ func (rcv *Monster) VectorOfLongsLength() int {
 	return 0
 }
 
+func (rcv *Monster) MutateVectorOfLongs(j int, n int64) bool {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(68))
+	if o != 0 {
+		a := rcv._tab.Vector(o)
+		return rcv._tab.MutateInt64(a+flatbuffers.UOffsetT(j*8), n)
+	}
+	return false
+}
+
 func (rcv *Monster) VectorOfDoubles(j int) float64 {
 	o := flatbuffers.UOffsetT(rcv._tab.Offset(70))
 	if o != 0 {
@@ -518,6 +563,15 @@ func (rcv *Monster) VectorOfDoublesLength() int {
 	return 0
 }
 
+func (rcv *Monster) MutateVectorOfDoubles(j int, n float64) bool {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(70))
+	if o != 0 {
+		a := rcv._tab.Vector(o)
+		return rcv._tab.MutateFloat64(a+flatbuffers.UOffsetT(j*8), n)
+	}
+	return false
+}
+
 func (rcv *Monster) ParentNamespaceTest(obj *MyGame.InParentNamespace) *MyGame.InParentNamespace {
 	o := flatbuffers.UOffsetT(rcv._tab.Offset(72))
 	if o != 0 {
@@ -580,6 +634,15 @@ func (rcv *Monster) VectorOfWeakReferencesLength() int {
 	return 0
 }
 
+func (rcv *Monster) MutateVectorOfWeakReferences(j int, n uint64) bool {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(78))
+	if o != 0 {
+		a := rcv._tab.Vector(o)
+		return rcv._tab.MutateUint64(a+flatbuffers.UOffsetT(j*8), n)
+	}
+	return false
+}
+
 func (rcv *Monster) VectorOfStrongReferrables(obj *Referrable, j int) bool {
 	o := flatbuffers.UOffsetT(rcv._tab.Offset(80))
 	if o != 0 {
@@ -629,6 +692,15 @@ func (rcv *Monster) VectorOfCoOwningReferencesLength() int {
 	return 0
 }
 
+func (rcv *Monster) MutateVectorOfCoOwningReferences(j int, n uint64) bool {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(84))
+	if o != 0 {
+		a := rcv._tab.Vector(o)
+		return rcv._tab.MutateUint64(a+flatbuffers.UOffsetT(j*8), n)
+	}
+	return false
+}
+
 func (rcv *Monster) NonOwningReference() uint64 {
 	o := flatbuffers.UOffsetT(rcv._tab.Offset(86))
 	if o != 0 {
@@ -658,6 +730,15 @@ func (rcv *Monster) VectorOfNonOwningReferencesLength() int {
 	return 0
 }
 
+func (rcv *Monster) MutateVectorOfNonOwningReferences(j int, n uint64) bool {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(88))
+	if o != 0 {
+		a := rcv._tab.Vector(o)
+		return rcv._tab.MutateUint64(a+flatbuffers.UOffsetT(j*8), n)
+	}
+	return false
+}
+
 func (rcv *Monster) AnyUniqueType() byte {
 	o := flatbuffers.UOffsetT(rcv._tab.Offset(90))
 	if o != 0 {
@@ -717,6 +798,15 @@ func (rcv *Monster) VectorOfEnumsLength() int {
 	return 0
 }
 
+func (rcv *Monster) MutateVectorOfEnums(j int, n Color) bool {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(98))
+	if o != 0 {
+		a := rcv._tab.Vector(o)
+		return rcv._tab.MutateInt8(a+flatbuffers.UOffsetT(j*1), n)
+	}
+	return false
+}
+
 func MonsterStart(builder *flatbuffers.Builder) {
 	builder.StartObject(48)
 }

tests/MyGame/Example/TypeAliases.go

@@ -163,6 +163,15 @@ func (rcv *TypeAliases) V8Length() int {
 	return 0
 }
 
+func (rcv *TypeAliases) MutateV8(j int, n int8) bool {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(24))
+	if o != 0 {
+		a := rcv._tab.Vector(o)
+		return rcv._tab.MutateInt8(a+flatbuffers.UOffsetT(j*1), n)
+	}
+	return false
+}
+
 func (rcv *TypeAliases) Vf64(j int) float64 {
 	o := flatbuffers.UOffsetT(rcv._tab.Offset(26))
 	if o != 0 {
@@ -180,6 +189,15 @@ func (rcv *TypeAliases) Vf64Length() int {
 	return 0
 }
 
+func (rcv *TypeAliases) MutateVf64(j int, n float64) bool {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(26))
+	if o != 0 {
+		a := rcv._tab.Vector(o)
+		return rcv._tab.MutateFloat64(a+flatbuffers.UOffsetT(j*8), n)
+	}
+	return false
+}
+
 func TypeAliasesStart(builder *flatbuffers.Builder) {
 	builder.StartObject(12)
 }

tests/go_test.go

@@ -334,6 +334,7 @@ func CheckMutateBuffer(org []byte, offset flatbuffers.UOffsetT, fail func(string
 		testcase{"Pos.Test2'", func() bool { return monster.Pos(nil).Test2() == int8(2) }},
 		testcase{"Pos.Test3.A", func() bool { return monster.Pos(nil).Test3(nil).A() == int16(5) }},
 		testcase{"Pos.Test3.B", func() bool { return monster.Pos(nil).Test3(nil).B() == int8(6) }},
+		testcase{"Inventory[2]", func() bool { return monster.Inventory(2) == byte(2) }},
 	}
 
 	testMutability := []testcase{
@@ -347,6 +348,7 @@ func CheckMutateBuffer(org []byte, offset flatbuffers.UOffsetT, fail func(string
 		testcase{"Pos.Test2", func() bool { return monster.Pos(nil).MutateTest2(20) }},
 		testcase{"Pos.Test3.A", func() bool { return monster.Pos(nil).Test3(nil).MutateA(50) }},
 		testcase{"Pos.Test3.B", func() bool { return monster.Pos(nil).Test3(nil).MutateB(60) }},
+		testcase{"Inventory[2]", func() bool { return monster.MutateInventory(2, 200) }},
 	}
 
 	testForMutatedValues := []testcase{
@@ -360,6 +362,7 @@ func CheckMutateBuffer(org []byte, offset flatbuffers.UOffsetT, fail func(string
 		testcase{"Pos.Test2'", func() bool { return monster.Pos(nil).Test2() == int8(20) }},
 		testcase{"Pos.Test3.A", func() bool { return monster.Pos(nil).Test3(nil).A() == int16(50) }},
 		testcase{"Pos.Test3.B", func() bool { return monster.Pos(nil).Test3(nil).B() == int8(60) }},
+		testcase{"Inventory[2]", func() bool { return monster.Inventory(2) == byte(200) }},
 	}
 
 	// make sure original values are okay
@@ -412,6 +415,7 @@ func CheckMutateBuffer(org []byte, offset flatbuffers.UOffsetT, fail func(string
 	monster.Pos(nil).MutateTest2(2)
 	monster.Pos(nil).Test3(nil).MutateA(5)
 	monster.Pos(nil).Test3(nil).MutateB(6)
+	monster.MutateInventory(2, 2)
 
 	for _, t := range testForOriginalValues {
 		if !t.testfn() {