Remove pencil.NewFrom(*pencil.Options) function (#24)

The `pencil.NewFrom(*pencil.Options)` [1] function was not necessary
because...

1. ...there was no way to get the actual options from a `pencil`
   instance.
2. ...new `pencil` instances with different options can be simply
   composed ny using the variadic parameter of the
   `pencil.New(pencil.Option...)` function.

Therefore the `pencil.NewFrom(*pencil.Options)` has been removed to
simply the package surface.

[1]: https://github.com/svengreb/nib/blob/2dac3395/pencil/pencil.go#L26-L27

Closes GH-23

inkpen/inkpen.go

@@ -17,13 +17,13 @@ import (
 // Inkpen composes pencil.Pencil to support colored output including automatic TTY and terminal color detection.
 type Inkpen struct {
 	*pencil.Pencil
-	opts Options
+	opts *Options
 }
 
 // New creates and returns a new inkpen with default Options and pencil.Options.
 func New(opts ...Option) *Inkpen {
 	opt := NewOptions(opts...)
-	p := pencil.NewFrom(opt.pencilOpts)
+	p := pencil.New(opt.pencilOpts...)
 	return &Inkpen{
 		Pencil: p,
 		opts:   opt,

inkpen/options.go

@@ -31,22 +31,24 @@ type IconColorFunc func(format string, args ...interface{}) string
 type Options struct {
 	coloredIcons   bool
 	iconColorFuncs map[nib.Verbosity]IconColorFunc
-	pencilOpts     pencil.Options
+	pencilOpts     []pencil.Option
 }
 
 // Option is a inkpen option.
 type Option func(*Options)
 
 // NewOptions creates new default inkpen Options and pencil.Options and merges them with the given list of Option.
 // By default the output writer is DefaultWriter and colorization for verbosity level icons is enabled.
-func NewOptions(opts ...Option) Options {
-	opt := Options{
+func NewOptions(opts ...Option) *Options {
+	opt := &Options{
 		iconColorFuncs: getDefaultIconColorFuncs(),
 		coloredIcons:   true,
-		pencilOpts:     pencil.NewOptions(pencil.WithWriter(DefaultWriter)),
+		pencilOpts: []pencil.Option{
+			pencil.WithWriter(DefaultWriter),
+		},
 	}
 	for _, o := range opts {
-		o(&opt)
+		o(opt)
 	}
 	return opt
 }
@@ -70,13 +72,9 @@ func WithIconColorFuncs(iconColorFuncs map[nib.Verbosity]IconColorFunc) Option {
 }
 
 // WithPencilOptions sets the given list of pencil.Option.
-func WithPencilOptions(pencilOpts ...pencil.Option) Option {
+func WithPencilOptions(opts ...pencil.Option) Option {
 	return func(o *Options) {
-		pOpts := o.pencilOpts
-		for _, po := range pencilOpts {
-			po(&pOpts)
-		}
-		o.pencilOpts = pOpts
+		o.pencilOpts = append(o.pencilOpts, opts...)
 	}
 }
 

pencil/options.go

@@ -42,16 +42,16 @@ type Option func(*Options)
 
 // NewOptions creates new default Options and merges them with the given options.
 // By default the verbosity level is DefaultVerbosity and icons are enabled with output to DefaultWriter.
-func NewOptions(opts ...Option) Options {
-	opt := Options{
+func NewOptions(opts ...Option) *Options {
+	opt := &Options{
 		Icons:     GetDefaultIcons(),
 		Prefixes:  []string{},
 		UseIcons:  true,
 		Verbosity: DefaultVerbosity,
 		Writer:    DefaultWriter,
 	}
 	for _, o := range opts {
-		o(&opt)
+		o(opt)
 	}
 	return opt
 }

pencil/pencil.go

@@ -17,15 +17,12 @@ import (
 
 // Pencil is a writer for human-facing CLI messages with support for custom prefixes and verbosity level icons.
 type Pencil struct {
-	opts Options
+	opts *Options
 }
 
 // New creates new pencil with default Options and merges them with the given list of Option.
 func New(opts ...Option) *Pencil { return &Pencil{opts: NewOptions(opts...)} }
 
-// NewFrom creates new pencil from the given Options.
-func NewFrom(opts Options) *Pencil { return &Pencil{opts: opts} }
-
 // Compile compiles the format and arguments, ensuring a trailing newline, when the given verbosity level is enabled.
 func (p *Pencil) Compile(v nib.Verbosity, format string, args ...interface{}) string {
 	if p.Enabled(v) {