Implement AddKeysFromFile()

fixtures/test.txt

@@ -0,0 +1,3 @@
+foo
+bar
+baz

trie.go

@@ -1,5 +1,13 @@
 package trie
 
+import (
+	"bufio"
+	"io"
+	"log"
+	"os"
+	"strings"
+)
+
 // Implementation of an R-Way Trie data structure.
 //
 // A Trie has a root Node which is the base of the tree.
@@ -62,6 +70,28 @@ func (t *Trie) AddKey(key string) int {
 	return t.addrune(t.Root(), runes, 0)
 }
 
+func (t *Trie) AddKeysFromFile(path string) {
+	file, err := os.Open(path)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	reader := bufio.NewReader(file)
+
+	for {
+		line, err := reader.ReadString('\n')
+		if err != nil {
+			if err == io.EOF {
+				break
+			}
+			log.Fatal(err)
+		}
+
+		line = strings.TrimSuffix(line, "\n")
+		t.AddKey(line)
+	}
+}
+
 func (t *Trie) Keys() []string {
 	return t.KeysWithPrefix("")
 }

trie_test.go

@@ -14,6 +14,26 @@ func TestTrieAdd(t *testing.T) {
 	}
 }
 
+func TestTrieAddFromFile(t *testing.T) {
+	path := "fixtures/test.txt"
+	expected := []string{"foo", "bar", "baz"}
+
+	trie := CreateTrie()
+	trie.AddKeysFromFile(path)
+	keys := trie.Keys()
+
+	kl := len(keys)
+	if kl != 3 {
+		t.Errorf("Expected 3 keys, got %d, keys were: %v", kl, trie.Keys())
+	}
+
+	for i, key := range keys {
+		if key != expected[i] {
+			t.Errorf("Expected %#v, got %#v", expected[i], key)
+		}
+	}
+}
+
 func TestTrieKeys(t *testing.T) {
 	trie := CreateTrie()
 	expected := []string{"bar", "foo"}