Merge pull request #113 from jolheiser/gen

Update generators

data/README.md

@@ -0,0 +1,10 @@
+## Updating `data`
+
+1. Go to [https://github.com/PrismarineJS/minecraft-data/tree/master/data/pc/{version}](https://github.com/PrismarineJS/minecraft-data/tree/master/data/pc)
+2. Update `version` in the following files if there is a new corresponding JSON file available:
+   - [gen_block.go](block/gen_block.go) - `blocks.json`
+   - [gen_entity.go](entity/gen_entity.go) - `entities.json`
+   - [gen_item.go](item/gen_item.go) - `items.json`
+   - [gen_packetid.go](packetid/gen_packetid.go) - `protocol.json`
+3. Update the `URL` in [gen_soundid.go](soundid/gen_soundid.go) (verify the URL returns a response first)
+4. Run `go generate ./...`

data/block/gen_block.go

@@ -0,0 +1,151 @@
+//+build generate
+
+// gen_blocks.go generates block information.
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"os"
+	"text/template"
+
+	"github.com/iancoleman/strcase"
+)
+
+const (
+	version = "1.17"
+	infoURL = "https://raw.githubusercontent.com/PrismarineJS/minecraft-data/master/data/pc/" + version + "/blocks.json"
+	//language=gohtml
+	blockTmpl = `// Code generated by gen_block.go; DO NOT EDIT.
+
+// Package block stores information about blocks in Minecraft.
+package block
+
+import (
+	"math"
+)
+
+// BitsPerBlock indicates how many bits are needed to represent all possible
+// block states. This value is used to determine the size of the global palette.
+var BitsPerBlock = int(math.Ceil(math.Log2(float64(len(StateID)))))
+
+// ID describes the numeric ID of a block.
+type ID uint32
+
+// Block describes information about a type of block.
+type Block struct {
+	ID          ID
+	DisplayName string
+	Name        string
+
+	Hardness   float64
+	Diggable   bool
+	DropIDs    []uint32
+	NeedsTools map[uint32]bool
+
+	MinStateID uint32
+	MaxStateID uint32
+
+	Transparent      bool
+	FilterLightLevel int
+	EmitLightLevel   int
+}
+
+var (
+	{{- range .}}
+	{{.CamelName}} = Block{
+		ID: {{.ID}}, 
+		DisplayName: "{{.DisplayName}}", 
+		Name: "{{.Name}}", 
+		Hardness: {{.Hardness}}, 
+		Diggable: {{.Diggable}}, 
+		DropIDs: []uint32{ {{- range .DropIDs}}{{.}},{{end -}} }, 
+		NeedsTools: map[uint32]bool{ {{- range $key, $val := .NeedsTools}}{{$key}}: {{$val}},{{end -}} }, 
+		MinStateID: {{.MinStateID}}, 
+		MaxStateID: {{.MaxStateID}}, 
+		Transparent: {{.Transparent}}, 
+		FilterLightLevel: {{.FilterLightLevel}}, 
+		EmitLightLevel: {{.EmitLightLevel}}, 
+	}{{end}}
+)
+
+// ByID is an index of minecraft blocks by their ID.
+var ByID = map[ID]*Block{ {{range .}}
+	{{.ID}}: &{{.CamelName}},{{end}}
+}
+
+// StateID maps all possible state IDs to a corresponding block ID.
+var StateID = map[uint32]ID{ {{range $block := .}}
+	{{- range .States}}
+	{{.}}: {{$block.ID}},
+	{{- end}}{{end}}
+}`
+)
+
+type Block struct {
+	ID          uint32 `json:"id"`
+	CamelName   string `json:"-"`
+	DisplayName string `json:"displayName"`
+	Name        string `json:"name"`
+
+	Hardness   float64         `json:"hardness"`
+	Diggable   bool            `json:"diggable"`
+	DropIDs    []uint32        `json:"drops"`
+	NeedsTools map[uint32]bool `json:"harvestTools"`
+
+	MinStateID uint32 `json:"minStateId"`
+	MaxStateID uint32 `json:"maxStateId"`
+
+	Transparent      bool `json:"transparent"`
+	FilterLightLevel int  `json:"filterLight"`
+	EmitLightLevel   int  `json:"emitLight"`
+}
+
+func (b Block) States() []uint32 {
+	if b.MinStateID == b.MaxStateID {
+		return []uint32{b.MinStateID}
+	}
+	states := make([]uint32, 0)
+	for i := b.MinStateID; i <= b.MaxStateID; i++ {
+		states = append(states, i)
+	}
+	return states
+}
+
+func downloadInfo() ([]*Block, error) {
+	resp, err := http.Get(infoURL)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	var data []*Block
+	if err := json.NewDecoder(resp.Body).Decode(&data); err != nil {
+		return nil, err
+	}
+	for _, d := range data {
+		d.CamelName = strcase.ToCamel(d.Name)
+	}
+	return data, nil
+}
+
+//go:generate go run $GOFILE
+//go:generate go fmt block.go
+func main() {
+	fmt.Println("generating block.go")
+	blocks, err := downloadInfo()
+	if err != nil {
+		panic(err)
+	}
+
+	f, err := os.Create("block.go")
+	if err != nil {
+		panic(err)
+	}
+	defer f.Close()
+
+	if err := template.Must(template.New("").Parse(blockTmpl)).Execute(f, blocks); err != nil {
+		panic(err)
+	}
+}

data/block/gen_blocks.go

@@ -1,201 +0,0 @@
-//+build ignore
-
-// gen_blocks.go generates block information.
-package main
-
-import (
-	"encoding/json"
-	"fmt"
-	"go/ast"
-	"go/format"
-	"go/token"
-	"net/http"
-	"os"
-	"reflect"
-	"strconv"
-
-	"github.com/iancoleman/strcase"
-)
-
-const (
-	infoURL = "https://raw.githubusercontent.com/PrismarineJS/minecraft-data/master/data/pc/1.17/blocks.json"
-)
-
-type Block struct {
-	ID          uint32 `json:"id"`
-	DisplayName string `json:"displayName"`
-	Name        string `json:"name"`
-
-	Hardness   float64         `json:"hardness"`
-	Diggable   bool            `json:"diggable"`
-	DropIDs    []uint32        `json:"drops"`
-	NeedsTools map[uint32]bool `json:"harvestTools"`
-
-	MinStateID uint32 `json:"minStateId"`
-	MaxStateID uint32 `json:"maxStateId"`
-
-	Transparent      bool `json:"transparent"`
-	FilterLightLevel int  `json:"filterLight"`
-	EmitLightLevel   int  `json:"emitLight"`
-}
-
-func downloadInfo() ([]Block, error) {
-	resp, err := http.Get(infoURL)
-	if err != nil {
-		return nil, err
-	}
-	defer resp.Body.Close()
-
-	var data []Block
-	if err := json.NewDecoder(resp.Body).Decode(&data); err != nil {
-		return nil, err
-	}
-	return data, nil
-}
-
-func makeBlockDeclaration(blocks []Block) *ast.DeclStmt {
-	out := &ast.DeclStmt{Decl: &ast.GenDecl{Tok: token.VAR}}
-
-	for _, b := range blocks {
-		t := reflect.TypeOf(b)
-		fields := make([]ast.Expr, t.NumField())
-
-		for i := 0; i < t.NumField(); i++ {
-			ft := t.Field(i)
-
-			var val ast.Expr
-			switch ft.Type.Kind() {
-			case reflect.Uint32, reflect.Int:
-				val = &ast.BasicLit{Kind: token.INT, Value: fmt.Sprint(reflect.ValueOf(b).Field(i))}
-			case reflect.Float64:
-				val = &ast.BasicLit{Kind: token.FLOAT, Value: fmt.Sprint(reflect.ValueOf(b).Field(i))}
-			case reflect.String:
-				val = &ast.BasicLit{Kind: token.STRING, Value: strconv.Quote(reflect.ValueOf(b).Field(i).String())}
-			case reflect.Bool:
-				val = &ast.BasicLit{Kind: token.IDENT, Value: fmt.Sprint(reflect.ValueOf(b).Field(i).Bool())}
-
-			case reflect.Slice:
-				val = &ast.CompositeLit{
-					Type: &ast.ArrayType{
-						Elt: &ast.BasicLit{Kind: token.IDENT, Value: ft.Type.Elem().Name()},
-					},
-				}
-				v := reflect.ValueOf(b).Field(i)
-				switch ft.Type.Elem().Kind() {
-				case reflect.Uint32, reflect.Int:
-					for x := 0; x < v.Len(); x++ {
-						val.(*ast.CompositeLit).Elts = append(val.(*ast.CompositeLit).Elts, &ast.BasicLit{
-							Kind:  token.INT,
-							Value: fmt.Sprint(v.Index(x)),
-						})
-					}
-				}
-
-			case reflect.Map:
-				// Must be the NeedsTools map of type map[uint32]bool.
-				m := &ast.CompositeLit{
-					Type: &ast.MapType{
-						Key:   &ast.BasicLit{Kind: token.IDENT, Value: ft.Type.Key().Name()},
-						Value: &ast.BasicLit{Kind: token.IDENT, Value: ft.Type.Elem().Name()},
-					},
-				}
-				iter := reflect.ValueOf(b).Field(i).MapRange()
-				for iter.Next() {
-					m.Elts = append(m.Elts, &ast.KeyValueExpr{
-						Key:   &ast.BasicLit{Kind: token.INT, Value: fmt.Sprint(iter.Key().Uint())},
-						Value: &ast.BasicLit{Kind: token.IDENT, Value: fmt.Sprint(iter.Value().Bool())},
-					})
-				}
-
-				val = m
-			}
-
-			fields[i] = &ast.KeyValueExpr{
-				Key:   &ast.Ident{Name: ft.Name},
-				Value: val,
-			}
-		}
-
-		out.Decl.(*ast.GenDecl).Specs = append(out.Decl.(*ast.GenDecl).Specs, &ast.ValueSpec{
-			Names: []*ast.Ident{{Name: strcase.ToCamel(b.Name)}},
-			Values: []ast.Expr{
-				&ast.CompositeLit{
-					Type: &ast.Ident{Name: reflect.TypeOf(b).Name()},
-					Elts: fields,
-				},
-			},
-		})
-	}
-
-	return out
-}
-
-//go:generate go run $GOFILE > ./packetid.go
-func main() {
-	blocks, err := downloadInfo()
-	if err != nil {
-		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
-		os.Exit(1)
-	}
-
-	fmt.Println(`// Code generated by gen_blocks.go; DO NOT EDIT.
-
-// Package block stores information about blocks in Minecraft.
-package block
-
-import (
-	"math"
-)
-
-// BitsPerBlock indicates how many bits are needed to represent all possible
-// block states. This value is used to determine the size of the global palette.
-var BitsPerBlock = int(math.Ceil(math.Log2(float64(len(StateID)))))
-
-// ID describes the numeric ID of a block.
-type ID uint32
-
-// Block describes information about a type of block.
-type Block struct {
-	ID          ID
-	DisplayName string
-	Name        string
-
-	Hardness   float64
-	Diggable   bool
-	DropIDs    []uint32
-	NeedsTools map[uint32]bool
-
-	MinStateID uint32
-	MaxStateID uint32
-
-	Transparent      bool
-	FilterLightLevel int
-	EmitLightLevel   int
-}
-
-`)
-	format.Node(os.Stdout, token.NewFileSet(), makeBlockDeclaration(blocks))
-
-	fmt.Println()
-	fmt.Println()
-	fmt.Println("// ByID is an index of minecraft blocks by their ID.")
-	fmt.Println("var ByID = map[ID]*Block{")
-	for _, b := range blocks {
-		fmt.Printf("  %d: &%s,\n", b.ID, strcase.ToCamel(b.Name))
-	}
-	fmt.Println("}")
-
-	fmt.Println()
-	fmt.Println("// StateID maps all possible state IDs to a corresponding block ID.")
-	fmt.Println("var StateID = map[uint32]ID{")
-	for _, b := range blocks {
-		if b.MinStateID == b.MaxStateID {
-			fmt.Printf("  %d: %d,\n", b.MinStateID, b.ID)
-		} else {
-			for i := b.MinStateID; i <= b.MaxStateID; i++ {
-				fmt.Printf("  %d: %d,\n", i, b.ID)
-			}
-		}
-	}
-	fmt.Println("}")
-}

data/entity/gen/gen_entity.go

@@ -1,152 +0,0 @@
-// gen_entity.go generates entity information.
-
-package main
-
-import (
-	"encoding/json"
-	"fmt"
-	"go/ast"
-	"go/format"
-	"go/token"
-	"net/http"
-	"os"
-	"reflect"
-	"strconv"
-
-	"github.com/iancoleman/strcase"
-)
-
-const (
-	infoURL = "https://raw.githubusercontent.com/PrismarineJS/minecraft-data/master/data/pc/1.17/entities.json"
-)
-
-type Entity struct {
-	ID          uint32 `json:"id"`
-	InternalID  uint32 `json:"internalId"`
-	DisplayName string `json:"displayName"`
-	Name        string `json:"name"`
-
-	Width  float64 `json:"width"`
-	Height float64 `json:"height"`
-
-	Type string `json:"type"`
-}
-
-func downloadInfo() ([]Entity, error) {
-	resp, err := http.Get(infoURL)
-	if err != nil {
-		return nil, err
-	}
-	defer resp.Body.Close()
-
-	var data []Entity
-	if err := json.NewDecoder(resp.Body).Decode(&data); err != nil {
-		return nil, err
-	}
-	return data, nil
-}
-
-func makeEntityDeclaration(entities []Entity) *ast.DeclStmt {
-	out := &ast.DeclStmt{Decl: &ast.GenDecl{Tok: token.VAR}}
-
-	for _, e := range entities {
-		t := reflect.TypeOf(e)
-		fields := make([]ast.Expr, t.NumField())
-
-		for i := 0; i < t.NumField(); i++ {
-			ft := t.Field(i)
-
-			var val ast.Expr
-			switch ft.Type.Kind() {
-			case reflect.Uint32, reflect.Int:
-				val = &ast.BasicLit{Kind: token.INT, Value: fmt.Sprint(reflect.ValueOf(e).Field(i))}
-			case reflect.Float64:
-				val = &ast.BasicLit{Kind: token.FLOAT, Value: fmt.Sprint(reflect.ValueOf(e).Field(i))}
-			case reflect.String:
-				val = &ast.BasicLit{Kind: token.STRING, Value: strconv.Quote(reflect.ValueOf(e).Field(i).String())}
-			case reflect.Bool:
-				val = &ast.BasicLit{Kind: token.IDENT, Value: fmt.Sprint(reflect.ValueOf(e).Field(i).Bool())}
-
-			case reflect.Slice:
-				val = &ast.CompositeLit{
-					Type: &ast.ArrayType{
-						Elt: &ast.BasicLit{Kind: token.IDENT, Value: ft.Type.Elem().Name()},
-					},
-				}
-				v := reflect.ValueOf(e).Field(i)
-				switch ft.Type.Elem().Kind() {
-				case reflect.Uint32, reflect.Int:
-					for x := 0; x < v.Len(); x++ {
-						val.(*ast.CompositeLit).Elts = append(val.(*ast.CompositeLit).Elts, &ast.BasicLit{
-							Kind:  token.INT,
-							Value: fmt.Sprint(v.Index(x)),
-						})
-					}
-				}
-			}
-
-			fields[i] = &ast.KeyValueExpr{
-				Key:   &ast.Ident{Name: ft.Name},
-				Value: val,
-			}
-		}
-
-		out.Decl.(*ast.GenDecl).Specs = append(out.Decl.(*ast.GenDecl).Specs, &ast.ValueSpec{
-			Names: []*ast.Ident{{Name: strcase.ToCamel(e.Name)}},
-			Values: []ast.Expr{
-				&ast.CompositeLit{
-					Type: &ast.Ident{Name: reflect.TypeOf(e).Name()},
-					Elts: fields,
-				},
-			},
-		})
-	}
-
-	return out
-}
-
-//go:generate go run $GOFILE
-//go:generate go fmt ../entity.go
-func main() {
-	entities, err := downloadInfo()
-	if err != nil {
-		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
-		os.Exit(1)
-	}
-
-	f, err := os.Create("../entity.go")
-	if err != nil {
-		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
-		os.Exit(1)
-	}
-	defer f.Close()
-
-	fmt.Fprintln(f, `// Code generated by gen_entity.go DO NOT EDIT.
-// Package entity stores information about entities in Minecraft.
-package entity
-// ID describes the numeric ID of an entity.
-type ID uint32
-
-// Entity describes information about a type of entity.
-type Entity struct {
-	ID          ID
-	InternalID  uint32
-	DisplayName string
-	Name        string
-	Width  float64
-	Height float64
-	Type     string
-}`)
-	format.Node(f, token.NewFileSet(), makeEntityDeclaration(entities))
-
-	fmt.Fprintln(f)
-	fmt.Fprintln(f)
-	fmt.Fprintln(f, "// ByID is an index of minecraft entities by their ID.")
-	fmt.Fprintln(f, "var ByID = map[ID]*Entity{")
-	for _, e := range entities {
-		fmt.Fprintf(f, "  %d: &%s,\n", e.ID, strcase.ToCamel(e.Name))
-	}
-	fmt.Fprintln(f, "}")
-
-	fmt.Fprintln(f)
-}

data/entity/gen_entity.go

@@ -0,0 +1,104 @@
+//+build generate
+
+// gen_entity.go generates entity information.
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"os"
+	"text/template"
+
+	"github.com/iancoleman/strcase"
+)
+
+const (
+	version = "1.17"
+	infoURL = "https://raw.githubusercontent.com/PrismarineJS/minecraft-data/master/data/pc/" + version + "/entities.json"
+	//language=gohtml
+	entityTmpl = `// Code generated by gen_entity.go DO NOT EDIT.
+// Package entity stores information about entities in Minecraft.
+package entity
+// ID describes the numeric ID of an entity.
+type ID uint32
+
+// Entity describes information about a type of entity.
+type Entity struct {
+ID          ID
+InternalID  uint32
+DisplayName string
+Name        string
+Width  float64
+Height float64
+Type     string
+}
+
+var (
+	{{- range .}}
+	{{.CamelName}} = Entity{
+		ID: {{.ID}},
+		InternalID: {{.InternalID}},
+		DisplayName: "{{.DisplayName}}",
+		Name: "{{.Name}}",
+		Width: {{.Width}},
+		Height: {{.Height}},
+		Type: "{{.Type}}",
+	}{{end}}
+)
+
+// ByID is an index of minecraft entities by their ID.
+var ByID = map[ID]*Entity{ {{range .}}
+	{{.ID}}: &{{.CamelName}},{{end}}
+}`
+)
+
+type Entity struct {
+	ID          uint32 `json:"id"`
+	InternalID  uint32 `json:"internalId"`
+	CamelName   string `json:"-"`
+	DisplayName string `json:"displayName"`
+	Name        string `json:"name"`
+
+	Width  float64 `json:"width"`
+	Height float64 `json:"height"`
+
+	Type string `json:"type"`
+}
+
+func downloadInfo() ([]*Entity, error) {
+	resp, err := http.Get(infoURL)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	var data []*Entity
+	if err := json.NewDecoder(resp.Body).Decode(&data); err != nil {
+		return nil, err
+	}
+	for _, d := range data {
+		d.CamelName = strcase.ToCamel(d.Name)
+	}
+	return data, nil
+}
+
+//go:generate go run $GOFILE
+//go:generate go fmt entity.go
+func main() {
+	fmt.Println("generating entity.go")
+	entities, err := downloadInfo()
+	if err != nil {
+		panic(err)
+	}
+
+	f, err := os.Create("entity.go")
+	if err != nil {
+		panic(err)
+	}
+	defer f.Close()
+
+	if err := template.Must(template.New("").Parse(entityTmpl)).Execute(f, entities); err != nil {
+		panic(err)
+	}
+}

data/item/gen_item.go

@@ -1,139 +1,26 @@
-// gen_blocks.go generates block information.
+//+build generate
-
-//+build ignore
 
+// gen_item.go generates item information.
 package main
 
 import (
 	"encoding/json"
 	"fmt"
-	"go/ast"
-	"go/format"
-	"go/token"
 	"net/http"
 	"os"
-	"reflect"
+	"text/template"
-	"strconv"
 
 	"github.com/iancoleman/strcase"
 )
 
 const (
-	infoURL = "https://raw.githubusercontent.com/PrismarineJS/minecraft-data/master/data/pc/1.17/items.json"
+	version = "1.17"
-)
+	infoURL = "https://raw.githubusercontent.com/PrismarineJS/minecraft-data/master/data/pc/" + version + "/items.json"
-
+	//language=gohtml
-type Item struct {
+	itemTmpl = `// Code generated by gen_item.go DO NOT EDIT.
-	ID          uint32 `json:"id"`
+// Package item stores information about items in Minecraft.
-	DisplayName string `json:"displayName"`
-	Name        string `json:"name"`
-	StackSize   uint   `json:"stackSize"`
-}
-
-func downloadInfo() ([]Item, error) {
-	resp, err := http.Get(infoURL)
-	if err != nil {
-		return nil, err
-	}
-	defer resp.Body.Close()
-
-	var data []Item
-	if err := json.NewDecoder(resp.Body).Decode(&data); err != nil {
-		return nil, err
-	}
-	return data, nil
-}
-
-func makeItemDeclaration(blocks []Item) *ast.DeclStmt {
-	out := &ast.DeclStmt{Decl: &ast.GenDecl{Tok: token.VAR}}
-
-	for _, b := range blocks {
-		t := reflect.TypeOf(b)
-		fields := make([]ast.Expr, t.NumField())
-
-		for i := 0; i < t.NumField(); i++ {
-			ft := t.Field(i)
-
-			var val ast.Expr
-			switch ft.Type.Kind() {
-			case reflect.Uint32, reflect.Int, reflect.Uint:
-				val = &ast.BasicLit{Kind: token.INT, Value: fmt.Sprint(reflect.ValueOf(b).Field(i))}
-			case reflect.Float64:
-				val = &ast.BasicLit{Kind: token.FLOAT, Value: fmt.Sprint(reflect.ValueOf(b).Field(i))}
-			case reflect.String:
-				val = &ast.BasicLit{Kind: token.STRING, Value: strconv.Quote(reflect.ValueOf(b).Field(i).String())}
-			case reflect.Bool:
-				val = &ast.BasicLit{Kind: token.IDENT, Value: fmt.Sprint(reflect.ValueOf(b).Field(i).Bool())}
-
-			case reflect.Slice:
-				val = &ast.CompositeLit{
-					Type: &ast.ArrayType{
-						Elt: &ast.BasicLit{Kind: token.IDENT, Value: ft.Type.Elem().Name()},
-					},
-				}
-				v := reflect.ValueOf(b).Field(i)
-				switch ft.Type.Elem().Kind() {
-				case reflect.Uint32, reflect.Int:
-					for x := 0; x < v.Len(); x++ {
-						val.(*ast.CompositeLit).Elts = append(val.(*ast.CompositeLit).Elts, &ast.BasicLit{
-							Kind:  token.INT,
-							Value: fmt.Sprint(v.Index(x)),
-						})
-					}
-				}
-
-			case reflect.Map:
-				// Must be the NeedsTools map of type map[uint32]bool.
-				m := &ast.CompositeLit{
-					Type: &ast.MapType{
-						Key:   &ast.BasicLit{Kind: token.IDENT, Value: ft.Type.Key().Name()},
-						Value: &ast.BasicLit{Kind: token.IDENT, Value: ft.Type.Elem().Name()},
-					},
-				}
-				iter := reflect.ValueOf(b).Field(i).MapRange()
-				for iter.Next() {
-					m.Elts = append(m.Elts, &ast.KeyValueExpr{
-						Key:   &ast.BasicLit{Kind: token.INT, Value: fmt.Sprint(iter.Key().Uint())},
-						Value: &ast.BasicLit{Kind: token.IDENT, Value: fmt.Sprint(iter.Value().Bool())},
-					})
-				}
-
-				val = m
-			}
-
-			fields[i] = &ast.KeyValueExpr{
-				Key:   &ast.Ident{Name: ft.Name},
-				Value: val,
-			}
-		}
-
-		out.Decl.(*ast.GenDecl).Specs = append(out.Decl.(*ast.GenDecl).Specs, &ast.ValueSpec{
-			Names: []*ast.Ident{{Name: strcase.ToCamel(b.Name)}},
-			Values: []ast.Expr{
-				&ast.CompositeLit{
-					Type: &ast.Ident{Name: reflect.TypeOf(b).Name()},
-					Elts: fields,
-				},
-			},
-		})
-	}
-
-	return out
-}
-
-func main() {
-	items, err := downloadInfo()
-	if err != nil {
-		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
-		os.Exit(1)
-	}
-
-	fmt.Println(`// Package item stores information about items in Minecraft.
 package item
 
-import (
-	"math"
-)
-
 // ID describes the numeric ID of an item.
 type ID uint32
 
@@ -145,24 +32,65 @@ type Item struct {
 	StackSize   uint
 }
 
-`)
+var (
-	format.Node(os.Stdout, token.NewFileSet(), makeItemDeclaration(items))
+	{{- range .}}
+	{{.CamelName}} = Item{
+		ID: {{.ID}},
+		DisplayName: "{{.DisplayName}}",
+		Name: "{{.Name}}",
+		StackSize: {{.StackSize}},
+	}{{end}}
+)
 
-	fmt.Println()
+// ByID is an index of minecraft items by their ID.
-	fmt.Println()
+var ByID = map[ID]*Item{ {{range .}}
-	fmt.Println("// ByID is an index of minecraft items by their ID.")
+	{{.ID}}: &{{.CamelName}},{{end}}
-	fmt.Println("var ByID = map[ID]*Item{")
+}`
-	for _, i := range items {
+)
-		fmt.Printf("  %d: &%s,\n", i.ID, strcase.ToCamel(i.Name))
-	}
-	fmt.Println("}")
-	fmt.Println()
 
-	fmt.Println("// ByName is an index of minecraft items by their name.")
+type Item struct {
-	fmt.Println("var ByName = map[string]*Item{")
+	ID          uint32 `json:"id"`
-	for _, i := range items {
+	CamelName   string `json:"-"`
-		fmt.Printf("  %q: &%s,\n", i.Name, strcase.ToCamel(i.Name))
+	DisplayName string `json:"displayName"`
-	}
+	Name        string `json:"name"`
-	fmt.Println("}")
+	StackSize   uint   `json:"stackSize"`
-	fmt.Println()
+}
+
+func downloadInfo() ([]*Item, error) {
+	resp, err := http.Get(infoURL)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	var data []*Item
+	if err := json.NewDecoder(resp.Body).Decode(&data); err != nil {
+		return nil, err
+	}
+	for _, d := range data {
+		d.CamelName = strcase.ToCamel(d.Name)
+	}
+	return data, nil
+}
+
+//go:generate go run $GOFILE
+//go:generate go fmt item.go
+func main() {
+	fmt.Println("generating item.go")
+	items, err := downloadInfo()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+
+	f, err := os.Create("item.go")
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+	defer f.Close()
+
+	if err := template.Must(template.New("").Parse(itemTmpl)).Execute(f, items); err != nil {
+		panic(err)
+	}
 }

data/lang/gen_lang.go

@@ -1,11 +1,13 @@
-// This program can automatic download language.json file and convert into .go
+//+build generate
+
+// This program can automatically download language.json file and convert into .go
 package main
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
-	"log"
 	"net/http"
 	"os"
 	"path/filepath"
@@ -15,9 +17,23 @@ import (
 	"text/template"
 )
 
+var (
+	//language=gohtml
+	langTmpl = `// Code generated by downloader.go; DO NOT EDIT. 
+package {{.Name}}
+{{if ne .Name "en_us"}}
+import "github.com/Tnze/go-mc/chat"
+
+func init() { chat.SetLanguage(Map) }
+{{end}}
+var Map = {{.LangMap | printf "%#v"}}
+`
+)
+
 //go:generate go run $GOFILE
 //go:generate go fmt ./...
 func main() {
+	fmt.Println("generating langs")
 	if len(os.Args) == 2 {
 		f, err := os.Open(os.Args[1])
 		if err != nil {
@@ -27,17 +43,15 @@ func main() {
 		readLang("en_us", f)
 		return
 	}
-	// Pseudo code for get versionURL:
+
-	// $manifest = {https://launchermeta.mojang.com/mc/game/version_manifest.json}
+	versionURL, err := assetIndexURL()
-	// $latest = $manifest.latest.release
+	if err != nil {
-	// $version = {$manifest.versions[where .id == $latest ].url}
+		panic(err)
-	// $versionURL = $version.assetIndex.url
+	}
-	versionURL := "https://launchermeta.mojang.com/v1/packages/e5af543d9b3ce1c063a97842c38e50e29f961f00/1.17.json"
-	log.Print("start generating lang packages")
 
 	resp, err := http.Get(versionURL)
 	if err != nil {
-		log.Fatal(err)
+		panic(err)
 	}
 	defer resp.Body.Close()
 
@@ -50,7 +64,7 @@ func main() {
 
 	err = json.NewDecoder(resp.Body).Decode(&list)
 	if err != nil {
-		log.Fatal(err)
+		panic(err)
 	}
 
 	tasks := make(chan string)
@@ -76,13 +90,11 @@ func main() {
 }
 
 func lang(name, hash string) {
-	log.Print("generating ", name, " package")
-
 	//download language
 	LangURL := "http://resources.download.minecraft.net/" + hash[:2] + "/" + hash
 	resp, err := http.Get(LangURL)
 	if err != nil {
-		log.Fatal(err)
+		panic(err)
 	}
 	defer resp.Body.Close()
 	readLang(name, resp.Body)
@@ -93,7 +105,7 @@ func readLang(name string, r io.Reader) {
 	var LangMap map[string]string
 	err := json.NewDecoder(r).Decode(&LangMap)
 	if err != nil {
-		log.Fatal("unmarshal json fail: ", err)
+		panic(err)
 	}
 	trans(LangMap)
 
@@ -102,12 +114,12 @@ func readLang(name string, r io.Reader) {
 	// mkdir
 	err = os.Mkdir(pName, 0777)
 	if err != nil && !os.IsExist(err) {
-		log.Fatal(err)
+		panic(err)
 	}
 
 	f, err := os.OpenFile(filepath.Join(pName, name+".go"), os.O_CREATE|os.O_RDWR|os.O_TRUNC, 0666)
 	if err != nil {
-		log.Fatal(err)
+		panic(err)
 	}
 	defer f.Close()
 
@@ -121,18 +133,9 @@ func readLang(name string, r io.Reader) {
 		LangMap: LangMap,
 	}
 
-	tmpl := template.Must(template.New("code_template").Parse(
+	tmpl := template.Must(template.New("").Parse(langTmpl))
-		`// Code generated by downloader.go; DO NOT EDIT. 
-package {{.Name}}
-{{if ne .Name "en_us"}}
-import "github.com/Tnze/go-mc/chat"
-
-func init() { chat.SetLanguage(Map) }
-{{end}}
-var Map = {{.LangMap | printf "%#v"}}
-`))
 	if err := tmpl.Execute(f, genData); err != nil {
-		log.Fatal(err)
+		panic(err)
 	}
 }
 
@@ -148,10 +151,66 @@ func trans(m map[string]string) {
 				var index int
 				_, err := fmt.Sscanf(s, "%%%d$s", &index)
 				if err != nil {
-					log.Fatal(err)
+					panic(err)
 				}
 				return fmt.Sprintf("%%[%d]s", index)
 			})
 		}
 	}
 }
+
+func assetIndexURL() (string, error) {
+	// Pseudo code for get versionURL:
+	// $manifest = {https://launchermeta.mojang.com/mc/game/version_manifest.json}
+	// $latest = $manifest.latest.release
+	// $versionURL = {$manifest.versions[where .id == $latest ].url}
+	// $assetIndexURL = $version.assetIndex.url
+	var manifest struct {
+		Latest struct {
+			Release string `json:"release"`
+		} `json:"latest"`
+		Versions []struct{
+			ID string `json:"id"`
+			URL string `json:"url"`
+		} `json:"versions"`
+	}
+
+	manifestRes, err := http.Get("https://launchermeta.mojang.com/mc/game/version_manifest.json")
+	if err != nil {
+		return "", fmt.Errorf("could not reach version manifest: %w", err)
+	}
+	defer manifestRes.Body.Close()
+
+	if err := json.NewDecoder(manifestRes.Body).Decode(&manifest); err != nil {
+		return "", fmt.Errorf("could not decode manifest JSON: %w", err)
+	}
+
+	var versionURL string
+	for _, v := range manifest.Versions {
+		if strings.EqualFold(manifest.Latest.Release, v.ID) {
+			versionURL = v.URL
+			break
+		}
+	}
+	if versionURL == "" {
+		return "", errors.New("could not determine versionURL")
+	}
+
+	var version struct{
+		AssetIndex struct{
+			URL string `json:"url"`
+		} `json:"assetIndex"`
+	}
+
+	versionRes, err := http.Get(versionURL)
+	if err != nil {
+		return "", fmt.Errorf("could not reach versionURL: %w", err)
+	}
+	defer versionRes.Body.Close()
+
+	if err := json.NewDecoder(versionRes.Body).Decode(&version); err != nil {
+		return "", fmt.Errorf("could not decode version JSON: %w", err)
+	}
+
+	return version.AssetIndex.URL, nil
+}

data/packetid/gen_packetid.go

@@ -1,4 +1,6 @@
-// gen_packetIDs.go generates the enumeration of packet IDs used on the wire.
+//+build generate
+
+//gen_packetid.go generates the enumeration of packet IDs used on the wire.
 package main
 
 import (
@@ -13,7 +15,9 @@ import (
 )
 
 const (
-	protocolURL  = "https://raw.githubusercontent.com/PrismarineJS/minecraft-data/master/data/pc/1.17.1/protocol.json"
+	version     = "1.17.1"
+	protocolURL = "https://raw.githubusercontent.com/PrismarineJS/minecraft-data/master/data/pc/" + version + "/protocol.json"
+	//language=gohtml
 	packetidTmpl = `// This file is automatically generated by gen_packetIDs.go. DO NOT EDIT.
 
 package packetid
@@ -161,24 +165,22 @@ func downloadInfo() (*protocolIDs, error) {
 }
 
 //go:generate go run $GOFILE
-//go:generate go fmt ../packetid.go
+//go:generate go fmt packetid.go
 func main() {
+	fmt.Println("generating packetid.go")
 	pIDs, err := downloadInfo()
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		panic(err)
-		os.Exit(1)
 	}
 
-	f, err := os.Create("../packetid.go")
+	f, err := os.Create("packetid.go")
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		panic(err)
-		os.Exit(1)
 	}
 	defer f.Close()
 
 	tmpl := template.Must(template.New("packetIDs").Parse(packetidTmpl))
 	if err := tmpl.Execute(f, pIDs); err != nil {
-		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		panic(err)
-		os.Exit(1)
 	}
 }

data/soundid/gen_soundIDs.go

@@ -1,96 +0,0 @@
-//+build ignore
-
-// gen_soundIDs.go generates the enumeration of sound IDs.
-package main
-
-import (
-	"encoding/json"
-	"fmt"
-	"net/http"
-	"os"
-	"sort"
-)
-
-const (
-	protocolURL = "https://pokechu22.github.io/Burger/1.17.1.json"
-)
-
-type sound struct {
-	ID   int64
-	Name string
-}
-
-//go:generate go run $GOFILE
-func main() {
-	sounds, err := downloadSoundInfo()
-	if err != nil {
-		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
-		os.Exit(1)
-	}
-
-	f, err := os.Create("soundid.go")
-	if err != nil {
-		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
-		os.Exit(1)
-	}
-	defer f.Close()
-
-	fmt.Fprintln(f, "// Code generated by gen_soundIDs.go. DO NOT EDIT.")
-	fmt.Fprintln(f)
-	fmt.Fprintln(f, "package soundid")
-	fmt.Fprintln(f)
-
-	fmt.Fprintln(f, "// SoundID represents a sound ID used in the minecraft protocol.")
-	fmt.Fprintln(f, "type SoundID int32")
-	fmt.Fprintln(f)
-	fmt.Fprintln(f, "// SoundNames - map of ids to names for sounds.")
-
-	fmt.Fprintln(f, "var SoundNames map[SoundID]string = map[SoundID]string{")
-	for _, v := range sounds {
-		fmt.Fprintf(f, `    %d: "%s",`, v.ID, v.Name)
-		fmt.Fprintln(f)
-	}
-	fmt.Fprintln(f, "}")
-	fmt.Fprintln(f)
-
-	fmt.Fprintln(f, "// GetSoundNameByID helper method")
-	fmt.Fprintln(f, "func GetSoundNameByID(id SoundID) (string,bool) {")
-	fmt.Fprintln(f, "    name, ok := SoundNames[id]")
-	fmt.Fprintln(f, "    return name, ok")
-	fmt.Fprintln(f, "}")
-}
-
-func downloadSoundInfo() ([]sound, error) {
-	resp, err := http.Get(protocolURL)
-	if err != nil {
-		return nil, err
-	}
-	defer resp.Body.Close()
-
-	x := []map[string]interface{}{}
-
-	// if err := json.Unmarshal([]byte(data), &x); err != nil {
-	if err := json.NewDecoder(resp.Body).Decode(&x); err != nil {
-		return nil, err
-	}
-
-	out := []sound{}
-	for i := range x {
-		if sounds, ok := x[i]["sounds"]; ok {
-			// fmt.Fprintf("sounds: %#v\n", sounds)
-			for _, value := range sounds.(map[string]interface{}) {
-				// fmt.Fprintf("%d: %s\n", int64(value.(map[string]interface{})["id"].(float64)), value.(map[string]interface{})["name"])
-				out = append(out, sound{ID: int64(value.(map[string]interface{})["id"].(float64)), Name: value.(map[string]interface{})["name"].(string)})
-			}
-		} else {
-			// fmt.Fprintf("NO SOUNDS FOUND IN DATA!")
-			return nil, fmt.Errorf("No sounds found in data from %s", protocolURL)
-		}
-	}
-
-	sort.SliceStable(out, func(i, j int) bool {
-		return out[i].ID < out[j].ID
-	})
-
-	return out, nil
-}

data/soundid/gen_soundid.go

@@ -0,0 +1,96 @@
+//+build generate
+
+// gen_soundid.go generates the enumeration of sound IDs.
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"os"
+	"sort"
+	"text/template"
+)
+
+const (
+	version     = "1.17.1"
+	protocolURL = "https://pokechu22.github.io/Burger/" + version + ".json"
+	//language=gohtml
+	soundTmpl = `// Code generated by gen_soundid.go. DO NOT EDIT.
+
+package soundid
+
+// SoundID represents a sound ID used in the minecraft protocol.
+type SoundID int32
+
+// SoundNames - map of ids to names for sounds.
+var SoundNames = map[SoundID]string{ {{range .}}
+	{{.ID}}: "{{.Name}}",{{end}}
+}
+
+// GetSoundNameByID helper method
+func GetSoundNameByID(id SoundID) (string, bool) {
+	name, ok := SoundNames[id]
+	return name, ok
+}`
+)
+
+type Sound struct {
+	ID   int64
+	Name string
+}
+
+//go:generate go run $GOFILE
+func main() {
+	fmt.Println("generating soundid.go")
+	sounds, err := downloadSoundInfo()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+
+	f, err := os.Create("soundid.go")
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+	defer f.Close()
+
+	if err := template.Must(template.New("").Parse(soundTmpl)).Execute(f, sounds); err != nil {
+		panic(err)
+	}
+}
+
+func downloadSoundInfo() ([]*Sound, error) {
+	resp, err := http.Get(protocolURL)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	// I'm not sure why the response returns a list, it appears to ever only have a single object...
+	var data []struct {
+		Sounds map[string]Sound `json:"sounds"`
+	}
+
+	if err := json.NewDecoder(resp.Body).Decode(&data); err != nil {
+		return nil, err
+	}
+
+	out := make([]*Sound, 0)
+	for _, d := range data {
+		if has := len(d.Sounds); has > 0 {
+			for _, val := range d.Sounds {
+				out = append(out, &Sound{ID: val.ID, Name: val.Name})
+			}
+		} else {
+			return nil, fmt.Errorf("no sounds found in data from %s", protocolURL)
+		}
+	}
+
+	sort.SliceStable(out, func(i, j int) bool {
+		return out[i].ID < out[j].ID
+	})
+
+	return out, nil
+}

data/soundid/soundid.go

@@ -1,4 +1,4 @@
-// Code generated by gen_soundIDs.go. DO NOT EDIT.
+// Code generated by gen_soundid.go. DO NOT EDIT.
 
 package soundid
 
@@ -6,7 +6,7 @@ package soundid
 type SoundID int32
 
 // SoundNames - map of ids to names for sounds.
-var SoundNames map[SoundID]string = map[SoundID]string{
+var SoundNames = map[SoundID]string{ 
 	0: "ambient.cave",
 	1: "ambient.basalt_deltas.additions",
 	2: "ambient.basalt_deltas.loop",