refactor: use maps instead of sorted slices

sloggen.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"bytes"
-	"cmp"
 	"fmt"
 	"go/format"
 	"io"
@@ -14,6 +13,8 @@ import (
 	"gopkg.in/yaml.v3"
 )
 
+// NOTE: when iterating over a map, text/template visits the elements in sorted key order.
+
 var tmpl = template.Must(template.New("").Funcs(funcs).Parse(
 	`// Code generated by go-simpler.org/sloggen. DO NOT EDIT.
 
@@ -23,24 +24,24 @@ package {{$.Pkg}}
 import "{{.}}"
 {{end}}
 
-{{range $.Levels -}}
-const Level{{title .Name}} = slog.Level({{.Severity}})
+{{range $severity, $name := $.Levels -}}
+const Level{{title $name}} = slog.Level({{$severity}})
 {{end}}
 
 {{range $.Consts -}}
 const {{snakeToCamel .}} = "{{.}}"
 {{end}}
 
-{{range $.Attrs -}}
-func {{snakeToCamel .Key}}(value {{.Type}}) slog.Attr { return slog.{{slogFunc .Type}}("{{.Key}}", value) }
+{{range $key, $type := $.Attrs -}}
+func {{snakeToCamel $key}}(value {{$type}}) slog.Attr { return slog.{{slogFunc $type}}("{{$key}}", value) }
 {{end}}
 
 {{if $.HasCustomLevels}}
 func ParseLevel(s string) (slog.Level, error) {
 	switch strings.ToUpper(s) {
-	{{range $.Levels -}}
-	case "{{upper .Name}}":
-		return Level{{title .Name}}, nil
+	{{range $_, $name := $.Levels -}}
+	case "{{upper $name}}":
+		return Level{{title $name}}, nil
 	{{end -}}
 	default:
 		return 0, fmt.Errorf("slog: level string %q: unknown name", s)
@@ -52,9 +53,9 @@ func ReplaceAttr(_ []string, attr slog.Attr) slog.Attr {
 		return attr
 	}
 	switch attr.Value.Any().(slog.Level) {
-	{{range $.Levels -}}
-	case Level{{title .Name}}:
-		attr.Value = slog.StringValue("{{upper .Name}}")
+	{{range $_, $name := $.Levels -}}
+	case Level{{title $name}}:
+		attr.Value = slog.StringValue("{{upper $name}}")
 	{{end -}}
 	}
 	return attr
@@ -63,9 +64,9 @@ func ReplaceAttr(_ []string, attr slog.Attr) slog.Attr {
 
 {{if $l := $.Logger}}
 type Logger struct{ Logger *slog.Logger }
-{{range $l.Levels}}
-func (l *Logger) {{title .Name}}({{if $l.Context}}ctx context.Context, {{end}}msg string, {{if $l.AttrAPI}}attrs ...slog.Attr{{else}}args ...any{{end}}) {
-	l.log({{if $l.Context}}ctx{{else}}context.Background(){{end}}, {{if not $.HasCustomLevels}}slog.{{end}}Level{{title .Name}}, msg, {{if $l.AttrAPI}}attrs{{else}}args{{end}})
+{{range $_, $name := $l.Levels}}
+func (l *Logger) {{title $name}}({{if $l.Context}}ctx context.Context, {{end}}msg string, {{if $l.AttrAPI}}attrs ...slog.Attr{{else}}args ...any{{end}}) {
+	l.log({{if $l.Context}}ctx{{else}}context.Background(){{end}}, {{if not $.HasCustomLevels}}slog.{{end}}Level{{title $name}}, msg, {{if $l.AttrAPI}}attrs{{else}}args{{end}})
 }
 {{end}}
 func (l *Logger) log(ctx context.Context, level slog.Level, msg string, {{if $l.AttrAPI}}attrs []slog.Attr{{else}}args []any{{end}}) {
@@ -106,22 +107,14 @@ type (
 	config struct {
 		Pkg             string
 		Imports         []string
-		Levels          []level
+		Levels          map[int]string // severity:name
 		Consts          []string
-		Attrs           []attr
+		Attrs           map[string]string // key:type
 		Logger          *logger
 		HasCustomLevels bool
 	}
-	level struct {
-		Name     string
-		Severity int
-	}
-	attr struct {
-		Key  string
-		Type string
-	}
 	logger struct {
-		Levels  []level
+		Levels  map[int]string
 		AttrAPI bool
 		Context bool
 	}
@@ -131,9 +124,9 @@ func readConfig(r io.Reader) (*config, error) {
 	var data struct {
 		Pkg     string              `yaml:"pkg"`
 		Imports []string            `yaml:"imports"`
-		Levels  []map[string]int    `yaml:"levels"` // name:severity
+		Levels  []map[string]int    `yaml:"levels"`
 		Consts  []string            `yaml:"consts"`
-		Attrs   []map[string]string `yaml:"attrs"` // key:type
+		Attrs   []map[string]string `yaml:"attrs"`
 		Logger  *struct {
 			API     string `yaml:"api"`
 			Context bool   `yaml:"context"`
@@ -146,37 +139,31 @@ func readConfig(r io.Reader) (*config, error) {
 	cfg := config{
 		Pkg:             data.Pkg,
 		Imports:         data.Imports,
-		Levels:          make([]level, len(data.Levels)),
+		Levels:          make(map[int]string, len(data.Levels)),
 		Consts:          data.Consts,
-		Attrs:           make([]attr, len(data.Attrs)),
+		Attrs:           make(map[string]string, len(data.Attrs)),
 		Logger:          nil,
 		HasCustomLevels: false,
 	}
 	if cfg.Pkg == "" {
 		cfg.Pkg = "slogx"
 	}
 
-	for i, m := range data.Levels {
+	for _, m := range data.Levels {
 		name, severity := getKV(m)
-		cfg.Levels[i] = level{name, severity}
+		cfg.Levels[severity] = name
 
 		switch slog.Level(severity) {
 		case slog.LevelDebug, slog.LevelInfo, slog.LevelWarn, slog.LevelError:
 		default:
 			cfg.HasCustomLevels = true
 		}
 	}
-	slices.SortFunc(cfg.Levels, func(l1, l2 level) int {
-		return cmp.Compare(l1.Severity, l2.Severity)
-	})
 
-	for i, m := range data.Attrs {
+	for _, m := range data.Attrs {
 		key, typ := getKV(m)
-		cfg.Attrs[i] = attr{key, typ}
+		cfg.Attrs[key] = typ
 	}
-	slices.SortFunc(cfg.Attrs, func(a1, a2 attr) int {
-		return cmp.Compare(a1.Key, a2.Key)
-	})
 
 	if data.Logger != nil {
 		cfg.Logger = &logger{
@@ -186,11 +173,11 @@ func readConfig(r io.Reader) (*config, error) {
 		}
 
 		if len(cfg.Levels) == 0 {
-			cfg.Logger.Levels = []level{
-				{"debug", int(slog.LevelDebug)},
-				{"info", int(slog.LevelInfo)},
-				{"warn", int(slog.LevelWarn)},
-				{"error", int(slog.LevelError)},
+			cfg.Logger.Levels = map[int]string{
+				int(slog.LevelDebug): "debug",
+				int(slog.LevelInfo):  "info",
+				int(slog.LevelWarn):  "warn",
+				int(slog.LevelError): "error",
 			}
 		}
 

sloggen_test.go

@@ -18,11 +18,11 @@ import (
 var cfg = config{
 	Pkg:     "test",
 	Imports: []string{"fmt", "log/slog", "strings", "time"},
-	Levels:  []level{{Name: "custom", Severity: -8}},
+	Levels:  map[int]string{-8: "custom"},
 	Consts:  []string{"foo"},
-	Attrs: []attr{
-		{Key: "bar", Type: "time.Time"},
-		{Key: "baz", Type: "time.Duration"},
+	Attrs: map[string]string{
+		"bar": "time.Time",
+		"baz": "time.Duration",
 	},
 	HasCustomLevels: true,
 }