word magic

huffman.go

@@ -15,10 +15,10 @@ func (n Node) Lookup(value interface{}) *Node {
 	return nil
 }
 
-func NewPathTree(paths []string) *Node {
+func NewWordTree(words []string) *Node {
 	nodes := []*Node{}
-	for i := range paths {
-		nodes = append(nodes, &Node{Weight: int64(i + 1), Value: paths[i]})
+	for i := range words {
+		nodes = append(nodes, &Node{Weight: int64(i + 1), Value: words[i]})
 	}
 
 	h := nodeInterface(nodes)

huffman_test.go

@@ -6,15 +6,8 @@ import (
 )
 
 func TestNode(t *testing.T) {
-  paths := []string{
-    "/content/dist/rhel/server/6/$releasever/$relarch/os",
-    "/content/dist/rhui/server/6/$releasever/$relarch/os",
-    "/content/beta/rhel/server/6/$releasever/$relarch/os",
-    "/content/beta/rhel/server/7/$releasever/$relarch/os",
-    "/content/beta/rhui/server/6/$releasever/$relarch/os",
-    "/content/beta/rhui/server/7/$releasever/$relarch/os",
-  }
-
-  pt := NewPathTree(paths)
+  // Paths defined in words_test.go
+	w := GetWeights(Paths, "/")
+  pt := NewWordTree(w.Sorted())
   fmt.Printf("%#v\n", pt)
 }

words.go

@@ -0,0 +1,66 @@
+package huff
+
+import (
+	"sort"
+	"strings"
+)
+
+type Words []Word
+
+// Returns the position of the word, or -1 if not present
+func (w Words) Contains(word string) int {
+	for i := range w {
+		if w[i].Value == word {
+			return i
+		}
+	}
+	return -1
+}
+
+// add word or increment existing word's counter
+func (w *Words) InsertOrUpdate(word string) {
+	ref := *w
+	if i := w.Contains(word); i >= 0 {
+		ref[i].Count += 1
+	} else {
+		ref = append(ref, Word{Count: 0, Value: word})
+	}
+	*w = ref
+}
+
+// get a string array, with the most frequent words first
+func (w Words) Sorted() []string {
+	wi := wordsInterface(w)
+	sort.Sort(wi)
+	list := []string{}
+	for i := range wi {
+		list = append(list, wi[i].Value)
+	}
+	for i, j := 0, len(list)-1; i < j; i, j = i+1, j-1 {
+		list[i], list[j] = list[j], list[i]
+	}
+	return list
+}
+
+type wordsInterface []Word
+
+func (wi wordsInterface) Len() int           { return len(wi) }
+func (wi wordsInterface) Less(i, j int) bool { return wi[i].Count < wi[j].Count }
+func (wi wordsInterface) Swap(i, j int)      { wi[i], wi[j] = wi[j], wi[i] }
+
+type Word struct {
+	Count int64
+	Value string
+}
+
+// From an array of strings, split on 'sep' delimiter,
+// and return the cumulative weigting of all the words.
+func GetWeights(paths []string, sep string) Words {
+	words := &Words{}
+	for _, path := range paths {
+		for _, word := range strings.Split(path, sep) {
+			words.InsertOrUpdate(word)
+		}
+	}
+	return *words
+}

words_test.go

@@ -0,0 +1,21 @@
+package huff
+
+import (
+	"fmt"
+	"testing"
+)
+
+var Paths = []string{
+	"/content/dist/rhel/server/6/$releasever/$relarch/os",
+	"/content/dist/rhui/server/6/$releasever/$relarch/os",
+	"/content/beta/rhel/server/6/$releasever/$relarch/os",
+	"/content/beta/rhel/server/7/$releasever/$relarch/os",
+	"/content/beta/rhui/server/6/$releasever/$relarch/os",
+	"/content/beta/rhui/server/7/$releasever/$relarch/os",
+}
+
+func TestWords(t *testing.T) {
+	w := GetWeights(Paths, "/")
+	fmt.Printf("%#v\n", w)
+	fmt.Printf("%#v\n", w.Sorted())
+}