add flatbuffers

commit 6da1cf79d90eb242e7da5318241d42279a3df3ba
Author: Max Burke <max@urbanlogiq.com>
Date:   Sun Jan 19 14:47:28 2020 -0800

    [rust] Add use declarations to Rust-generated bindings for imported FB definitions (#5645)

    * Bugfix for Rust generation of union fields named with language keywords

flatbuffers/samples/sample_binary.go

@@ -0,0 +1,165 @@
+/*
+ * Copyright 2015 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// To run, use the `go_sample.sh` script.
+
+package main
+
+import (
+	sample "MyGame/Sample"
+	"fmt"
+	flatbuffers "github.com/google/flatbuffers/go"
+	"strconv"
+)
+
+// Example how to use Flatbuffers to create and read binary buffers.
+func main() {
+	builder := flatbuffers.NewBuilder(0)
+
+	// Create some weapons for our Monster ("Sword" and "Axe").
+	weaponOne := builder.CreateString("Sword")
+	weaponTwo := builder.CreateString("Axe")
+
+	sample.WeaponStart(builder)
+	sample.WeaponAddName(builder, weaponOne)
+	sample.WeaponAddDamage(builder, 3)
+	sword := sample.WeaponEnd(builder)
+
+	sample.WeaponStart(builder)
+	sample.WeaponAddName(builder, weaponTwo)
+	sample.WeaponAddDamage(builder, 5)
+	axe := sample.WeaponEnd(builder)
+
+	// Serialize the FlatBuffer data.
+	name := builder.CreateString("Orc")
+
+	sample.MonsterStartInventoryVector(builder, 10)
+	// Note: Since we prepend the bytes, this loop iterates in reverse.
+	for i := 9; i >= 0; i-- {
+		builder.PrependByte(byte(i))
+	}
+	inv := builder.EndVector(10)
+
+	sample.MonsterStartWeaponsVector(builder, 2)
+	// Note: Since we prepend the weapons, prepend in reverse order.
+	builder.PrependUOffsetT(axe)
+	builder.PrependUOffsetT(sword)
+	weapons := builder.EndVector(2)
+
+	pos := sample.CreateVec3(builder, 1.0, 2.0, 3.0)
+
+	sample.MonsterStart(builder)
+	sample.MonsterAddPos(builder, pos)
+	sample.MonsterAddHp(builder, 300)
+	sample.MonsterAddName(builder, name)
+	sample.MonsterAddInventory(builder, inv)
+	sample.MonsterAddColor(builder, sample.ColorRed)
+	sample.MonsterAddWeapons(builder, weapons)
+	sample.MonsterAddEquippedType(builder, sample.EquipmentWeapon)
+	sample.MonsterAddEquipped(builder, axe)
+	orc := sample.MonsterEnd(builder)
+
+	builder.Finish(orc)
+
+	// We now have a FlatBuffer that we could store on disk or send over a network.
+
+	// ...Saving to file or sending over a network code goes here...
+
+	// Instead, we are going to access this buffer right away (as if we just received it).
+
+	buf := builder.FinishedBytes()
+
+	// Note: We use `0` for the offset here, since we got the data using the
+	// `builder.FinishedBytes()` method. This simulates the data you would store/receive in your
+	// FlatBuffer. If you wanted to read from the `builder.Bytes` directly, you would need to
+	// pass in the offset of `builder.Head()`, as the builder actually constructs the buffer
+	// backwards.
+	monster := sample.GetRootAsMonster(buf, 0)
+
+	// Note: We did not set the `mana` field explicitly, so we get the
+	// default value.
+	assert(monster.Mana() == 150, "`monster.Mana()`", strconv.Itoa(int(monster.Mana())), "150")
+	assert(monster.Hp() == 300, "`monster.Hp()`", strconv.Itoa(int(monster.Hp())), "300")
+	assert(string(monster.Name()) == "Orc", "`string(monster.Name())`", string(monster.Name()),
+		"\"Orc\"")
+	assert(monster.Color() == sample.ColorRed, "`monster.Color()`",
+		strconv.Itoa(int(monster.Color())), strconv.Itoa(int(sample.ColorRed)))
+
+	// Note: Whenever you access a new object, like in `Pos()`, a new temporary accessor object
+	// gets created. If your code is very performance sensitive, you can pass in a pointer to an
+	// existing `Vec3` instead of `nil`. This allows you to reuse it across many calls to reduce
+	// the amount of object allocation/garbage collection.
+	assert(monster.Pos(nil).X() == 1.0, "`monster.Pos(nil).X()`",
+		strconv.FormatFloat(float64(monster.Pos(nil).X()), 'f', 1, 32), "1.0")
+	assert(monster.Pos(nil).Y() == 2.0, "`monster.Pos(nil).Y()`",
+		strconv.FormatFloat(float64(monster.Pos(nil).Y()), 'f', 1, 32), "2.0")
+	assert(monster.Pos(nil).Z() == 3.0, "`monster.Pos(nil).Z()`",
+		strconv.FormatFloat(float64(monster.Pos(nil).Z()), 'f', 1, 32), "3.0")
+
+	// For vectors, like `Inventory`, they have a method suffixed with 'Length' that can be used
+	// to query the length of the vector. You can index the vector by passing an index value
+	// into the accessor.
+	for i := 0; i < monster.InventoryLength(); i++ {
+		assert(monster.Inventory(i) == byte(i), "`monster.Inventory(i)`",
+			strconv.Itoa(int(monster.Inventory(i))), strconv.Itoa(int(byte(i))))
+	}
+
+	expectedWeaponNames := []string{"Sword", "Axe"}
+	expectedWeaponDamages := []int{3, 5}
+	weapon := new(sample.Weapon) // We need a `sample.Weapon` to pass into `monster.Weapons()`
+	// to capture the output of that function.
+	for i := 0; i < monster.WeaponsLength(); i++ {
+		if monster.Weapons(weapon, i) {
+			assert(string(weapon.Name()) == expectedWeaponNames[i], "`weapon.Name()`",
+				string(weapon.Name()), expectedWeaponNames[i])
+			assert(int(weapon.Damage()) == expectedWeaponDamages[i],
+				"`weapon.Damage()`", strconv.Itoa(int(weapon.Damage())),
+				strconv.Itoa(expectedWeaponDamages[i]))
+		}
+	}
+
+	// For FlatBuffer `union`s, you can get the type of the union, as well as the union
+	// data itself.
+	assert(monster.EquippedType() == sample.EquipmentWeapon, "`monster.EquippedType()`",
+		strconv.Itoa(int(monster.EquippedType())), strconv.Itoa(int(sample.EquipmentWeapon)))
+
+	unionTable := new(flatbuffers.Table)
+	if monster.Equipped(unionTable) {
+		// An example of how you can appropriately convert the table depending on the
+		// FlatBuffer `union` type. You could add `else if` and `else` clauses to handle
+		// other FlatBuffer `union` types for this field. (Similarly, this could be
+		// done in a switch statement.)
+		if monster.EquippedType() == sample.EquipmentWeapon {
+			unionWeapon := new(sample.Weapon)
+			unionWeapon.Init(unionTable.Bytes, unionTable.Pos)
+
+			assert(string(unionWeapon.Name()) == "Axe", "`unionWeapon.Name()`",
+				string(unionWeapon.Name()), "Axe")
+			assert(int(unionWeapon.Damage()) == 5, "`unionWeapon.Damage()`",
+				strconv.Itoa(int(unionWeapon.Damage())), strconv.Itoa(5))
+		}
+	}
+
+	fmt.Printf("The FlatBuffer was successfully created and verified!\n")
+}
+
+// A helper function to print out if an assertion failed.
+func assert(assertPassed bool, codeExecuted string, actualValue string, expectedValue string) {
+	if assertPassed == false {
+		panic("Assert failed! " + codeExecuted + " (" + actualValue +
+			") was not equal to " + expectedValue + ".")
+	}
+}