cleaned up code and add comments

README.md

@@ -13,8 +13,7 @@ fast and flexible way of exploring HTML from the terminal.
 
 ## Examples
 
-Download a webpage with `wget`. _Please exercise restraint when using any 
+Download a webpage with `wget`.
-automated request tool._ 
 
 ```bash
 $ wget http://en.wikipedia.org/wiki/Robots_exclusion_standard -O robots.html

main.go

@@ -6,12 +6,11 @@ import (
 	"github.com/ericchiang/pup/selector"
 	"io"
 	"os"
-	"regexp"
 	"strconv"
 	"strings"
 )
 
-const VERSION = "0.1.0"
+const VERSION string = "0.1.0"
 
 var (
 	// Flags
@@ -20,20 +19,17 @@ var (
 	maxPrintLevel int           = -1
 	printNumber   bool          = false
 	printColor    bool          = false
-
-	// Helpers
-	whitespaceRegexp *regexp.Regexp = regexp.MustCompile(`^\s*$`)
-	preWhitespace    *regexp.Regexp = regexp.MustCompile(`^\s+`)
-	postWhitespace   *regexp.Regexp = regexp.MustCompile(`\s+$`)
 )
 
+// Print to stderr and exit
 func Fatal(format string, args ...interface{}) {
 	fmt.Fprintf(os.Stderr, format, args...)
 	fmt.Fprintf(os.Stderr, "\n")
 	os.Exit(1)
 }
 
-func printHelp() {
+// Print help to stderr and quit
+func PrintHelp() {
 	helpString := `Usage
 
     pup [list of css selectors]
@@ -54,7 +50,8 @@ Flags
 	Fatal(helpString, VERSION)
 }
 
-func processFlags(cmds []string) []string {
+// Process command arguments and return all non-flags.
+func ProcessFlags(cmds []string) []string {
 	var i int
 	var err error
 	defer func() {
@@ -77,7 +74,7 @@ func processFlags(cmds []string) []string {
 			}
 			i++
 		case "-h", "--help":
-			printHelp()
+			PrintHelp()
 			os.Exit(1)
 		case "-i", "--indent":
 			indentLevel, err := strconv.Atoi(cmds[i+1])
@@ -109,8 +106,9 @@ func processFlags(cmds []string) []string {
 	return nonFlagCmds[:n]
 }
 
+// pup
 func main() {
-	cmds := processFlags(os.Args[1:])
+	cmds := ProcessFlags(os.Args[1:])
 	root, err := html.Parse(inputStream)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, err.Error())
@@ -121,9 +119,9 @@ func main() {
 		PrintNode(root, 0)
 		os.Exit(0)
 	}
-	selectors := make([]selector.Selector, len(cmds))
+	selectors := make([]*selector.Selector, len(cmds))
 	for i, cmd := range cmds {
-		selectors[i], err = selector.ParseSelector(cmd)
+		selectors[i], err = selector.NewSelector(cmd)
 		if err != nil {
 			fmt.Fprintf(os.Stderr, err.Error())
 			os.Exit(2)
@@ -134,7 +132,8 @@ func main() {
 	for _, selector := range selectors {
 		selected = []*html.Node{}
 		for _, node := range currNodes {
-			selected = append(selected, selector.FindAllChildren(node)...)
+			selected = append(selected,
+				selector.FindAllChildren(node)...)
 		}
 		currNodes = selected
 	}

printing.go

@@ -5,13 +5,20 @@ import (
 	"code.google.com/p/go.net/html/atom"
 	"fmt"
 	"github.com/fatih/color"
+	"regexp"
 )
 
 var (
+	// Colors
 	tagColor     *color.Color = color.New(color.FgYellow).Add(color.Bold)
 	tokenColor                = color.New(color.FgCyan).Add(color.Bold)
 	attrKeyColor              = color.New(color.FgRed)
 	quoteColor                = color.New(color.FgBlue)
+
+	// Regexp helpers
+	whitespaceRegexp *regexp.Regexp = regexp.MustCompile(`^\s*$`)
+	preWhitespace    *regexp.Regexp = regexp.MustCompile(`^\s+`)
+	postWhitespace   *regexp.Regexp = regexp.MustCompile(`\s+$`)
 )
 
 func printIndent(level int) {
@@ -48,6 +55,7 @@ func printChildren(n *html.Node, level int) {
 	}
 }
 
+// Print a node and all of it's children to `maxlevel`.
 func PrintNode(n *html.Node, level int) {
 	switch n.Type {
 	case html.TextNode:

selector/selector.go

@@ -7,20 +7,22 @@ import (
 	"strings"
 )
 
+// A CSS Selector
 type Selector struct {
 	Class, ID, Name *regexp.Regexp
 	Attrs           map[string]*regexp.Regexp
 }
 
-type SelectorType string
+type selectorField string
 
 const (
-	Class SelectorType = "class"
+	Class selectorField = "class"
-	ID    SelectorType = "id"
+	ID    selectorField = "id"
-	Name  SelectorType = "name"
+	Name  selectorField = "name"
 )
 
-func setTypeValue(s *Selector, a SelectorType, v string) error {
+// Set a field of this selector.
+func (s *Selector) setFieldValue(a selectorField, v string) error {
 	if v == "" {
 		return nil
 	}
@@ -41,7 +43,8 @@ func setTypeValue(s *Selector, a SelectorType, v string) error {
 	return nil
 }
 
-func ParseSelector(s string) (Selector, error) {
+// Convert a string to a selector.
+func NewSelector(s string) (*Selector, error) {
 	attrs := map[string]*regexp.Regexp{}
 	selector := &Selector{nil, nil, nil, attrs}
 	nextAttr := Name
@@ -49,26 +52,30 @@ func ParseSelector(s string) (Selector, error) {
 	for i, c := range s {
 		switch c {
 		case '.':
-			err := setTypeValue(selector, nextAttr, s[start:i])
+			err := selector.setFieldValue(nextAttr, s[start:i])
 			if err != nil {
-				return *selector, err
+				return selector, err
 			}
 			nextAttr = Class
 			start = i + 1
 		case '#':
-			err := setTypeValue(selector, nextAttr, s[start:i])
+			err := selector.setFieldValue(nextAttr, s[start:i])
 			if err != nil {
-				return *selector, err
+				return selector, err
 			}
 			nextAttr = ID
 			start = i + 1
 		}
 	}
-	setTypeValue(selector, nextAttr, s[start:])
+	err := selector.setFieldValue(nextAttr, s[start:])
-	return *selector, nil
+	if err != nil {
+		return selector, err
+	}
+	return selector, nil
 }
 
-func (sel Selector) FindAllChildren(node *html.Node) []*html.Node {
+// Find all nodes which match a selector.
+func (sel *Selector) FindAllChildren(node *html.Node) []*html.Node {
 	selected := []*html.Node{}
 	child := node.FirstChild
 	for child != nil {
@@ -79,7 +86,8 @@ func (sel Selector) FindAllChildren(node *html.Node) []*html.Node {
 	return selected
 }
 
-func (sel Selector) FindAll(node *html.Node) []*html.Node {
+// Find all nodes which match a selector. May return itself.
+func (sel *Selector) FindAll(node *html.Node) []*html.Node {
 	selected := []*html.Node{}
 	if sel.Match(node) {
 		return []*html.Node{node}
@@ -93,7 +101,8 @@ func (sel Selector) FindAll(node *html.Node) []*html.Node {
 	return selected
 }
 
-func (sel Selector) Match(node *html.Node) bool {
+// Does this selector match a given node?
+func (sel *Selector) Match(node *html.Node) bool {
 	if node.Type != html.ElementNode {
 		return false
 	}