Expand benchmarks, example (#331)

Expand the benchmark a bit; use the toml-test files for this.

Also revamp/expand the example, and benchmark this as well. Remove all
the other examples as they're not really all that useful.

README.md

@@ -208,4 +208,4 @@ type clients struct {
 Note that a case insensitive match will be tried if an exact match can't be
 found.
 
-A working example of the above can be found in `_examples/example.{go,toml}`.
+A working example of the above can be found in `_example/example.{go,toml}`.

_example/example.go

@@ -0,0 +1,112 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"reflect"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/BurntSushi/toml"
+)
+
+type (
+	example struct {
+		Title      string
+		Desc       string
+		Integers   []int
+		Floats     []float64
+		Times      []fmtTime
+		Duration   []duration
+		Distros    []distro
+		Servers    map[string]server
+		Characters map[string][]struct {
+			Name string
+			Rank string
+		}
+	}
+
+	server struct {
+		IP       string
+		Hostname string
+		Enabled  bool
+	}
+
+	distro struct {
+		Name     string
+		Packages string
+	}
+
+	duration struct{ time.Duration }
+	fmtTime  struct{ time.Time }
+)
+
+func (d *duration) UnmarshalText(text []byte) (err error) {
+	d.Duration, err = time.ParseDuration(string(text))
+	return err
+}
+
+func (t fmtTime) String() string {
+	f := "2006-01-02 15:04:05.999999999"
+	if t.Time.Hour() == 0 {
+		f = "2006-01-02"
+	}
+	if t.Time.Year() == 0 {
+		f = "15:04:05.999999999"
+	}
+	if t.Time.Location() == time.UTC {
+		f += " UTC"
+	} else {
+		f += " -0700"
+	}
+	return t.Time.Format(`"` + f + `"`)
+}
+
+func main() {
+	f := "example.toml"
+	if _, err := os.Stat(f); err != nil {
+		f = "_example/example.toml"
+	}
+
+	var config example
+	meta, err := toml.DecodeFile(f, &config)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+
+	indent := strings.Repeat(" ", 14)
+
+	fmt.Print("Decoded")
+	typ, val := reflect.TypeOf(config), reflect.ValueOf(config)
+	for i := 0; i < typ.NumField(); i++ {
+		indent := indent
+		if i == 0 {
+			indent = strings.Repeat(" ", 7)
+		}
+		fmt.Printf("%s%-11s → %v\n", indent, typ.Field(i).Name, val.Field(i).Interface())
+	}
+
+	fmt.Print("\nKeys")
+	keys := meta.Keys()
+	sort.Slice(keys, func(i, j int) bool { return keys[i].String() < keys[j].String() })
+	for i, k := range keys {
+		indent := indent
+		if i == 0 {
+			indent = strings.Repeat(" ", 10)
+		}
+		fmt.Printf("%s%-10s %s\n", indent, meta.Type(k...), k)
+	}
+
+	fmt.Print("\nUndecoded")
+	keys = meta.Undecoded()
+	sort.Slice(keys, func(i, j int) bool { return keys[i].String() < keys[j].String() })
+	for i, k := range keys {
+		indent := indent
+		if i == 0 {
+			indent = strings.Repeat(" ", 5)
+		}
+		fmt.Printf("%s%-10s %s\n", indent, meta.Type(k...), k)
+	}
+}

_example/example.toml

@@ -0,0 +1,53 @@
+# This is an example TOML document which shows most of its features.
+
+# Simple key/value with a string.
+title = "TOML example \U0001F60A"
+
+desc = """
+An example TOML document. \
+"""
+
+# Array with integers and floats in the various allowed formats.
+integers = [42, 0x42, 0o42, 0b0110]
+floats   = [1.42, 1e-02]
+
+# Array with supported datetime formats.
+times = [
+	2021-11-09T15:16:17+01:00,  # datetime with timezone.
+	2021-11-09T15:16:17Z,       # UTC datetime.
+	2021-11-09T15:16:17,        # local datetime.
+	2021-11-09,                 # local date.
+	15:16:17,                   # local time.
+]
+
+# Custom Unmarshal.
+duration = ["4m49s", "8m03s", "1231h15m55s"]
+
+# Table with inline tables.
+distros = [
+	{name = "Arch Linux", packages = "pacman"},
+	{name = "Void Linux", packages = "xbps"},
+	{name = "Debian",     packages = "apt"},
+]
+
+# Create new table; note the "servers" table is created implicitly.
+[servers.alpha]
+	# You can indent as you please, tabs or spaces.
+	ip        = '10.0.0.1'
+	hostname  = 'server1'
+	enabled   = false
+[servers.beta]
+	ip        = '10.0.0.2'
+	hostname  = 'server2'
+	enabled   = true
+
+# Start a new table array; note that the "characters" table is created implicitly.
+[[characters.star-trek]]
+	name = "James Kirk"
+	rank = "Captain"
+[[characters.star-trek]]
+	name = "Spock"
+	rank = "Science officer"
+
+[undecoded] # To show the MetaData.Undecoded() feature.
+	key = "This table intentionally left undecoded"