From 4c5821c7d50b77870b925b3a9e2af0667cc6d7d6 Mon Sep 17 00:00:00 2001
From: Greg <gmp@wow.st>
Date: Mon, 6 Aug 2018 12:35:35 -0400
Subject: [PATCH] Refactor pgen to use a visitor struct instead of globals.

---
 cmd/pgen/main.go     | 72 ++++++++++++++++++++++++--------------------
 generate/generate.go | 10 +++---
 2 files changed, 46 insertions(+), 36 deletions(-)

diff --git a/cmd/pgen/main.go b/cmd/pgen/main.go
index 876e316..4ed92a1 100644
--- a/cmd/pgen/main.go
+++ b/cmd/pgen/main.go
@@ -15,8 +15,6 @@ import (
 	"gitlab.wow.st/gmp/persist/generate"
 )
 
-type visitor struct{}
-
 func trimType(n *string) {
 	*n = pkgreg.ReplaceAllString(*n,"")
 	*n = treg.ReplaceAllString(*n,"")
@@ -39,19 +37,19 @@ func (v *visitor) Visit(node ast.Node) ast.Visitor {
 			tp = "float64"
 		}
 	case *ast.CompositeLit:
-		tp = types.TypeString(info.TypeOf(arg),types.RelativeTo(pkg))
+		tp = types.TypeString(v.info.TypeOf(arg),types.RelativeTo(v.pkg))
 	case *ast.Ident:
-		tp = types.TypeString(info.TypeOf(arg),types.RelativeTo(pkg))
+		tp = types.TypeString(v.info.TypeOf(arg),types.RelativeTo(v.pkg))
 		trimType(&tp)
 		for _, s := range impreg.FindAllStringSubmatchIndex(tp, -1) {
 			pkgname := impreg.ExpandString(make([]byte,0), "$1", tp, s)
-			needImps[string(pkgname)] = true
+			v.needImps[string(pkgname)] = true
 		}
 	default:
 	}
 
 	name := reg.ReplaceAllString(id.Name,"$1")
-	ts[name] = tps{fun: id.Name, name: name, typ: tp}
+	v.ts[name] = tps{fun: id.Name, name: name, typ: tp}
 	return nil
 }
 
@@ -59,43 +57,58 @@ type tps struct {
 	fun,name,typ string
 }
 
-var fset *token.FileSet
-var pkg *types.Package
-var ts map[string]tps
-var reg *regexp.Regexp
-var pkgreg *regexp.Regexp
-var impreg *regexp.Regexp
-var treg *regexp.Regexp
-var imps map[string]string
-var needImps map[string]bool
-var info *types.Info
+type visitor struct {
+	pkg *types.Package
+	ts map[string]tps
+	imps map[string]string
+	needImps map[string]bool
+	info *types.Info
+}
 
-func chkpkg(p *ast.Package) {
+var (
+	fset *token.FileSet
+	reg, pkgreg, impreg, treg *regexp.Regexp
+)
+
+func newVisitor() *visitor {
+	var v = &visitor{}
+	v.imps = make(map[string]string)
+	v.needImps = make(map[string]bool)
+	v.info = &types.Info{
+		Types:	make(map[ast.Expr]types.TypeAndValue),
+		Defs:	make(map[*ast.Ident]types.Object),
+		Uses:	make(map[*ast.Ident]types.Object)}
+	v.ts = make(map[string]tps)
+	v.needImps = make(map[string]bool)
+	return v
+}
+
+func chkpkg(p *ast.Package) (map[string]tps, []string) {
 	fs := make([]*ast.File,0)
 	for _,f := range p.Files {
 		fs = append(fs,f)
 	}
 
 	conf := types.Config{Error: func(error) {}, Importer: importer.Default()}
+	v := newVisitor()
 	var err error
-	info = &types.Info{
-		Types:	make(map[ast.Expr]types.TypeAndValue),
-		Defs:	make(map[*ast.Ident]types.Object),
-		Uses:	make(map[*ast.Ident]types.Object)}
-
-	pkg, err = conf.Check("main", fset, fs, info)
+	v.pkg, err = conf.Check("main", fset, fs, v.info)
 	if err != nil {
 		log.Print("Check:",err)
 	}
-	var v = &visitor{}
 	for _,f := range fs {
 		for _,is := range f.Imports {
 			name := is.Path.Value
 			shortName := pkgreg.ReplaceAllString(name,"")
-			imps[shortName] = name
+			v.imps[shortName] = name
 		}
 		ast.Walk(v,f)
 	}
+	imps := make([]string,0)
+	for shortName := range v.needImps {
+		imps = append(imps,v.imps[shortName])
+	}
+	return v.ts, imps
 }
 
 func init() {
@@ -105,8 +118,6 @@ func init() {
 	impreg = regexp.MustCompile(`([a-zA-Z_]+[a-zA-Z_0-9]+)\.[a-zA-Z_]+[a-zA-Z_0-9]+`)
 	treg = regexp.MustCompile(`untyped `)
 
-	imps = make(map[string]string)
-	needImps = make(map[string]bool)
 	fset = token.NewFileSet()
 
 	// clear out old generated files
@@ -130,8 +141,7 @@ func main() {
 	// run type checker on each package
 	for _,pkg := range pkgs {
 		log.Print("Processing package ",pkg.Name)
-		ts = make(map[string]tps)
-		chkpkg(pkg)
+		ts,imps := chkpkg(pkg)
 		if len(ts) == 0 {
 			continue
 		}
@@ -139,9 +149,7 @@ func main() {
 		for _,v := range ts {
 			g.Add(v.fun, v.name, v.typ)
 		}
-		for name := range needImps {
-			g.Import(imps[name])
-		}
+		g.Import(imps...)
 		var of *os.File
 		var err error
 		if pkg.Name == "main" {
diff --git a/generate/generate.go b/generate/generate.go
index 537fd2f..5cf188b 100644
--- a/generate/generate.go
+++ b/generate/generate.go
@@ -131,14 +131,16 @@ func (g *Generator) Add(newName, typName, typ string) {
 	g.firstone = false
 }
 
-func (g *Generator) Import(name string) {
+func (g *Generator) Import(ns ...string) {
 	if g.nodes == nil {
 		return
 	}
 
-	// strip quotation marks from imports
-	name = qexp.ReplaceAllString(name,"")
-	astutil.AddImport(g.fset, g.nodes, name)
+	for _,n := range ns {
+		// strip quotation marks from imports
+		n = qexp.ReplaceAllString(n,"")
+		astutil.AddImport(g.fset, g.nodes, n)
+	}
 }
 
 func (g *Generator) Save(of io.Writer) {