Documentation and golint cleanup for markup

markup.go

@@ -1,6 +1,6 @@
 // Copyright (c) 2013 by Michael Dvorkin. All Rights Reserved.
-// Use of this source code is governed by a MIT-style
+// Use of this source code is governed by a MIT-style license that can
-// license that can be found in the LICENSE file.
+// be found in the LICENSE file.
 
 package mop
 
@@ -10,39 +10,65 @@ import (
 	`strings`
 )
 
+// Markup implements some minimalistic text formatting conventions that
+// get translated to Termbox colors and attributes. To colorize a string
+// wrap it in <color-name>...</> tags. Unlike HTML each tag sets a new
+// color whereas the </> tag changes color back to default. For example:
+//
+// <green>Hello, <red>world!</>
+//
+// The color tags could be combined with the attributes: <b>...</b> for
+// bold, <u>...</u> for underline, and <r>...</r> for reverse. Unlike
+// colors the attributes require matching closing tag.
+//
+// The <right>...</right> tag is used to right align the enclosed string
+// (ex. when displaying current time in the upper right corner).
 type Markup struct {
-	tags	      map[string]termbox.Attribute
+	Foreground     termbox.Attribute	     // Foreground color.
-	Foreground    termbox.Attribute
+	Background     termbox.Attribute	     // Background color (so far always termbox.ColorDefault).
-	Background    termbox.Attribute
+	RightAligned   bool			     // True when the string is right aligned.
-	RightAligned  bool
+	tags	       map[string]termbox.Attribute  // Tags to Termbox translation hash.
+	regex	      *regexp.Regexp		     // Regex to identify the supported tag names.
 }
 
-//-----------------------------------------------------------------------------
+// Initialize creates tags to Termbox translation hash and sets default
-func (self *Markup) Initialize() *Markup {
+// colors and string alignment.
-	self.tags = make(map[string]termbox.Attribute)
+func (markup *Markup) Initialize() *Markup {
-	self.tags[`/`]       = termbox.ColorDefault
+	markup.Foreground      = termbox.ColorDefault
-	self.tags[`black`]   = termbox.ColorBlack
+	markup.Background      = termbox.ColorDefault
-	self.tags[`red`]     = termbox.ColorRed
+	markup.RightAligned    = false
-	self.tags[`green`]   = termbox.ColorGreen
+
-	self.tags[`yellow`]  = termbox.ColorYellow
+	markup.tags = make(map[string]termbox.Attribute)
-	self.tags[`blue`]    = termbox.ColorBlue
+	markup.tags[`/`]       = termbox.ColorDefault
-	self.tags[`magenta`] = termbox.ColorMagenta
+	markup.tags[`black`]   = termbox.ColorBlack
-	self.tags[`cyan`]    = termbox.ColorCyan
+	markup.tags[`red`]     = termbox.ColorRed
-	self.tags[`white`]   = termbox.ColorWhite
+	markup.tags[`green`]   = termbox.ColorGreen
-	self.tags[`right`]   = termbox.ColorDefault	// Termbox can combine attributes and a single color using bitwise OR.
+	markup.tags[`yellow`]  = termbox.ColorYellow
-	self.tags[`b`]       = termbox.AttrBold		// Attribute = 1 << (iota + 4)
+	markup.tags[`blue`]    = termbox.ColorBlue
-	self.tags[`u`]       = termbox.AttrUnderline
+	markup.tags[`magenta`] = termbox.ColorMagenta
-	self.tags[`r`]       = termbox.AttrReverse
+	markup.tags[`cyan`]    = termbox.ColorCyan
-	self.Foreground      = termbox.ColorDefault
+	markup.tags[`white`]   = termbox.ColorWhite
-	self.Background      = termbox.ColorDefault
+	markup.tags[`right`]   = termbox.ColorDefault	 // Termbox can combine attributes and a single color using bitwise OR.
-	self.RightAligned    = false
+	markup.tags[`b`]       = termbox.AttrBold	 // Attribute = 1 << (iota + 4)
-
+	markup.tags[`u`]       = termbox.AttrUnderline
-	return self
+	markup.tags[`r`]       = termbox.AttrReverse
+	markup.regex           = markup.supportedTags()  // Once we have the hash we could build the regex.
+
+	return markup
 }
 
-//-----------------------------------------------------------------------------
+// Tokenize works just like strings.Split() except the resulting array includes
-func (self *Markup) Tokenize(str string) []string {
+// the delimiters. For example, the "<green>Hello, <red>world!</>" string when
-	matches := self.supported_tags().FindAllStringIndex(str, -1)
+// tokenized by tags produces the following:
+//
+//   [0] "<green>"
+//   [1] "Hello, "
+//   [2] "<red>"
+//   [3] "world!"
+//   [4] "</>"
+//
+func (markup *Markup) Tokenize(str string) []string {
+	matches := markup.regex.FindAllStringIndex(str, -1)
 	strings := make([]string, 0, len(matches))
 
 	head, tail := 0, 0
@@ -50,9 +76,11 @@ func (self *Markup) Tokenize(str string) []string {
 		tail = match[0]
 		if match[1] != 0 {
 			if head != 0 || tail != 0 {
-				strings = append(strings, str[head:tail]) // Apend text between tags.
+				// Apend the text between tags.
+				strings = append(strings, str[head:tail])
 			}
-			strings = append(strings, str[match[0]:match[1]]) // Append tag.
+			// Append the tag itmarkup.
+			strings = append(strings, str[match[0]:match[1]])
 		}
 		head = match[1]
 	}
@@ -64,35 +92,37 @@ func (self *Markup) Tokenize(str string) []string {
 	return strings
 }
 
-//-----------------------------------------------------------------------------
+// IsTag returns true when the given string looks like markup tag. When the
-func (self *Markup) IsTag(str string) bool {
+// tag name matches one of the markup-supported tags it gets translated to
-	tag, open := probe_tag(str)
+// relevant Termbox attributes and colors.
+func (markup *Markup) IsTag(str string) bool {
+	tag, open := probeForTag(str)
 
 	if tag == `` {
 		return false
 	}
 
-	return self.process(tag, open)
+	return markup.process(tag, open)
 }
 
 //-----------------------------------------------------------------------------
-func (self *Markup) process(tag string, open bool) bool {
+func (markup *Markup) process(tag string, open bool) bool {
-	if attribute, ok := self.tags[tag]; ok {
+	if attribute, ok := markup.tags[tag]; ok {
 		switch tag {
 		case `right`:
-			self.RightAligned = open
+			markup.RightAligned = open  // On for <right>, off for </right>.
 		default:
 			if open {
 				if attribute >= termbox.AttrBold {
-					self.Foreground |= attribute
+					markup.Foreground |= attribute   // Set the Termbox attribute.
 				} else {
-					self.Foreground = attribute
+					markup.Foreground = attribute	 // Set the Termbox color.
 				}
 			} else {
 				if attribute >= termbox.AttrBold {
-					self.Foreground &= ^attribute
+					markup.Foreground &= ^attribute	 // Clear the Termbox attribute.
 				} else {
-					self.Foreground = termbox.ColorDefault
+					markup.Foreground = termbox.ColorDefault
 				}
 			}
 		}
@@ -101,14 +131,12 @@ func (self *Markup) process(tag string, open bool) bool {
 	return true
 }
 
-//
+// supportedTags returns regular expression that matches all possible tags
-// Return regular expression that matches all possible tags, i.e.
+// supported by the markup, i.e. </?black>|</?red>| ... |<?b>| ... |</?right>
-// </?black>|</?red>| ... |</?white>
+func (markup *Markup) supportedTags() *regexp.Regexp {
-//-----------------------------------------------------------------------------
-func (self *Markup) supported_tags() *regexp.Regexp {
 	arr := []string{}
 
-	for tag, _ := range self.tags {
+	for tag := range markup.tags {
 		arr = append(arr, `</?` + tag + `>`)
 	}
 
@@ -116,18 +144,16 @@ func (self *Markup) supported_tags() *regexp.Regexp {
 }
 
 //-----------------------------------------------------------------------------
-func probe_tag(str string) (string, bool) {
+func probeForTag(str string) (string, bool) {
 	if len(str) > 2 && str[0:1] == `<` && str[len(str)-1:] == `>` {
-		return extract_tag_name(str), str[1:2] != `/`
+		return extractTagName(str), str[1:2] != `/`
 	}
 
 	return ``, false
 }
 
-//
+// Extract tag name from the given tag, i.e. `<hello>` => `hello`.
-// Extract tag name from the given tag, i.e. `<hello>` => `hello`
+func extractTagName(str string) string {
-//-----------------------------------------------------------------------------
-func extract_tag_name(str string) string {
 	if len(str) < 3 {
 		return ``
 	} else if str[1:2] != `/` {