Update colors (#2)

Simplify example

Update colors

Add wrapping

Signed-off-by: jolheiser <john.olheiser@gmail.com>

Co-authored-by: jolheiser <john.olheiser@gmail.com>
Reviewed-on: https://gitea.com/jolheiser/beaver/pulls/2

README.md

@@ -49,3 +49,5 @@ Beaver allows you to customize the colors of various parts of the message
 // Set Trace logging to Magenta instead of Bold-Cyan
 color.Trace = color.New(color.FgMagenta)
 ```
+
+[More info for the `color` package](color/README.md)

color/README.md

@@ -0,0 +1,45 @@
+# Color
+
+Beaver comes with the `color` sub-package that can be used even without Beaver calls.
+
+## Formatting a string with a single attribute
+```go
+text := color.FgRed.Format("red")
+```
+
+## Formatting a string with a full color
+```go
+text := color.New(color.BgGreen, color.FgRed, color.Bold).Format("green background, red text, and bold")
+```
+
+## Formatting strings with multiple colors
+The following are different ways to print `This is a color test!`
+where the word `color` is red while everything else is `green`.
+
+### setup
+Assuming each example is preceded by
+```go
+green := color.New(color.FgGreen)
+red := color.New(color.FgRed)
+```
+
+#### pure `fmt.Println`
+```go
+fmt.Println(green.Format("This is a"), red.Format("color"), green.Format("test!"))
+```
+
+#### `color.Wrap`
+```go
+fmt.Println(green.Wrap("This is a #{color} test!", red))
+```
+
+#### string formatting with `fmt.Printf` and `color.Wrap`
+```go
+fmt.Printf(green.Wrap("This is a #{%s} test!\n", red), "color")
+```
+
+#### using a different directive prefix
+```go
+color.DirectivePrefix('$')
+fmt.Printf(green.Wrap("This is a ${%s} test!\n", red), "color")
+```

color/attribute.go

@@ -0,0 +1,87 @@
+package color
+
+// Attribute defines a single SGR Code
+type Attribute int
+
+// Logger attributes
+const (
+	Reset Attribute = iota
+	Bold
+	Faint
+	Italic
+	Underline
+	BlinkSlow
+	BlinkRapid
+	ReverseVideo
+	Concealed
+	CrossedOut
+)
+
+// Foreground text colors
+const (
+	FgBlack Attribute = iota + 30
+	FgRed
+	FgGreen
+	FgYellow
+	FgBlue
+	FgMagenta
+	FgCyan
+	FgWhite
+)
+
+// Foreground Hi-Intensity text colors
+const (
+	FgHiBlack Attribute = iota + 90
+	FgHiRed
+	FgHiGreen
+	FgHiYellow
+	FgHiBlue
+	FgHiMagenta
+	FgHiCyan
+	FgHiWhite
+)
+
+// Background text colors
+const (
+	BgBlack Attribute = iota + 40
+	BgRed
+	BgGreen
+	BgYellow
+	BgBlue
+	BgMagenta
+	BgCyan
+	BgWhite
+)
+
+// Background Hi-Intensity text colors
+const (
+	BgHiBlack Attribute = iota + 100
+	BgHiRed
+	BgHiGreen
+	BgHiYellow
+	BgHiBlue
+	BgHiMagenta
+	BgHiCyan
+	BgHiWhite
+)
+
+var attrCache = make(map[string]*Color)
+
+func attr(a Attribute) *Color {
+	if c, ok := attrCache[string(a)]; ok {
+		return c
+	}
+	c := New(a)
+	attrCache[string(a)] = c
+	return c
+}
+
+// Format is a quick way to format a string using a single attribute
+func (a Attribute) Format(text string) string {
+	return attr(a).Format(text)
+}
+
+// Format is a quick way to format a formatted string using a single attribute
+func (a Attribute) Formatf(text string, v ...interface{}) string {
+	return attr(a).Formatf(text, v...)
+}

color/color.go

@@ -2,82 +2,28 @@ package color
 
 import (
 	"fmt"
+	"regexp"
 	"strconv"
 	"strings"
 )
 
+const escape = "\x1b"
+
+var (
+	directive   = `{[^}]*}`
+	directiveRe = regexp.MustCompile("[#]" + directive)
+)
+
+// DirectivePrefix changes the directive prefix for parsing color wrap directives
+func DirectivePrefix(p rune) {
+	directiveRe = regexp.MustCompile("[" + string(p) + "]" + directive)
+}
+
 // Color defines a custom color object which is defined by SGR parameters.
 type Color struct {
 	Attrs []Attribute
 }
 
-// Attribute defines a single SGR Code
-type Attribute int
-
-const escape = "\x1b"
-
-// Logger attributes
-const (
-	Reset Attribute = iota
-	Bold
-	Faint
-	Italic
-	Underline
-	BlinkSlow
-	BlinkRapid
-	ReverseVideo
-	Concealed
-	CrossedOut
-)
-
-// Foreground text colors
-const (
-	FgBlack Attribute = iota + 30
-	FgRed
-	FgGreen
-	FgYellow
-	FgBlue
-	FgMagenta
-	FgCyan
-	FgWhite
-)
-
-// Foreground Hi-Intensity text colors
-const (
-	FgHiBlack Attribute = iota + 90
-	FgHiRed
-	FgHiGreen
-	FgHiYellow
-	FgHiBlue
-	FgHiMagenta
-	FgHiCyan
-	FgHiWhite
-)
-
-// Background text colors
-const (
-	BgBlack Attribute = iota + 40
-	BgRed
-	BgGreen
-	BgYellow
-	BgBlue
-	BgMagenta
-	BgCyan
-	BgWhite
-)
-
-// Background Hi-Intensity text colors
-const (
-	BgHiBlack Attribute = iota + 100
-	BgHiRed
-	BgHiGreen
-	BgHiYellow
-	BgHiBlue
-	BgHiMagenta
-	BgHiCyan
-	BgHiWhite
-)
-
 // New returns a new Color with attrs Attributes
 func New(attrs ...Attribute) *Color {
 	return &Color{Attrs: attrs}
@@ -118,17 +64,18 @@ func (c *Color) sequence() string {
 }
 
 func (c *Color) wrap(s string) string {
-	return c.format() + s + c.unformat()
+	return c.format() + s + unformat()
 }
 
 func (c *Color) format() string {
 	return fmt.Sprintf("%s[%sm", escape, c.sequence())
 }
 
-func (c *Color) unformat() string {
+func unformat() string {
 	return fmt.Sprintf("%s[%dm", escape, Reset)
 }
 
+// Format returns a string wrapped in the color
 func (c *Color) Format(text string) string {
 	if len(c.Attrs) > 0 {
 		return c.wrap(text)
@@ -136,6 +83,28 @@ func (c *Color) Format(text string) string {
 	return text
 }
 
+// Formatf returns a formatted string wrapped in the color
+func (c *Color) Formatf(format string, v ...interface{}) string {
+	return c.Format(fmt.Sprintf(format, v...))
+}
+
+func parse(text string, primary, secondary *Color) string {
+	for {
+		loc := directiveRe.FindStringIndex(text)
+		if loc == nil {
+			break
+		}
+		text = text[:loc[0]] + unformat() + secondary.Format(text[loc[0]+2:loc[1]-1]) + primary.format() + text[loc[1]:]
+	}
+	return text
+}
+
+// Wrap returns a string wrapped in a primary color, with #{} directives wrapped in a secondary color
+func (c *Color) Wrap(text string, secondary *Color) string {
+	text = parse(text, c, secondary)
+	return c.Format(text)
+}
+
 // ParseLevel parses a string and returns a Beaver Level's Color, defaulting to Info
 func ParseLevel(level string) *Color {
 	switch strings.ToUpper(level) {

logger.go

@@ -5,7 +5,6 @@ import (
 	"io"
 	"os"
 	"runtime"
-	"strings"
 	"time"
 
 	"go.jolheiser.com/beaver/color"
@@ -41,12 +40,12 @@ func New(writer io.Writer, level Level, opts FormatOptions) *Logger {
 
 func (l *Logger) write(level Level, text string) {
 	if l.Level <= level {
-		_, file, line, _ := runtime.Caller(l.skip)
 		var message string
 		if l.Format.TimePrefix {
 			message += color.Time.Format(timePrefix(time.Now())) + " "
 		}
 		if l.Format.StackPrefix {
+			_, file, line, _ := runtime.Caller(l.skip)
 			idx := len(file) - l.Format.StackLimit
 			if l.Format.StackLimit <= 0 {
 				idx = 0
@@ -75,11 +74,7 @@ func (l *Logger) write(level Level, text string) {
 }
 
 func (l *Logger) log(level Level, v ...interface{}) {
-	var args = make([]string, len(v))
+	text := fmt.Sprint(v...)
-	for i := 0; i < len(v); i++ {
-		args[i] = fmt.Sprintf("%v", v[i])
-	}
-	text := strings.Join(args, " ")
 	l.write(level, text)
 }