feat(trie): add trie package with Map and Set interfaces

trie/coverage_patch_test.go

@@ -0,0 +1,149 @@
+package trie
+
+import (
+	"testing"
+)
+
+func TestCoveragePatch(t *testing.T) {
+	sm := NewSliceMap[byte, int]()
+	m := NewMap[int]()
+
+	// 1. LongestPrefixOf on empty slice
+	slk, slv, slok := sm.LongestPrefixOf([]byte("xyz"))
+	if slok || len(slk) != 0 || slv != 0 {
+		t.Errorf("LongestPrefixOf empty slice failed")
+	}
+
+	// 2. Remove root values
+	m.Put("", 1)
+	m.Remove("")
+	if m.Size() != 0 {
+		t.Errorf("Remove empty string failed")
+	}
+
+	sm.Put([]byte{}, 1)
+	sm.Remove([]byte{})
+	if sm.Size() != 0 {
+		t.Errorf("Remove empty slice failed")
+	}
+
+	// 3. Remove non-existent long keys to hit removeNode nil children / missing key
+	m.Remove("ab")
+	m.Remove("xyz")
+	sm.Remove([]byte("ab"))
+	sm.Remove([]byte("xyz"))
+
+	// 4. Empty trie HasPrefix
+	emptyStrMap := NewMap[int]()
+	if emptyStrMap.HasPrefix("") {
+		t.Errorf("empty map should not have empty prefix")
+	}
+	emptySliceMap := NewSliceMap[byte, int]()
+	if emptySliceMap.HasPrefix([]byte{}) {
+		t.Errorf("empty slice map should not have empty prefix")
+	}
+
+	// 5. EntriesWithPrefix early exit
+	m.Put("abc", 1)
+	count := 0
+	for range m.EntriesWithPrefix("a") {
+		count++
+		break
+	}
+	if count != 1 {
+		t.Errorf("EntriesWithPrefix early exit failed")
+	}
+
+	sm.Put([]byte("abc"), 1)
+	count = 0
+	for range sm.EntriesWithPrefix([]byte("a")) {
+		count++
+		break
+	}
+	if count != 1 {
+		t.Errorf("EntriesWithPrefix early exit failed")
+	}
+
+	// 6. PrefixesOf early exit
+	count = 0
+	for range m.PrefixesOf("abc") {
+		count++
+		break
+	}
+	if count != 1 {
+		t.Errorf("PrefixesOf early exit failed")
+	}
+
+	count = 0
+	for range sm.PrefixesOf([]byte("abc")) {
+		count++
+		break
+	}
+	if count != 1 {
+		t.Errorf("PrefixesOf early exit failed")
+	}
+
+	count = 0
+	for range sm.PrefixesOf([]byte("abc")) {
+		count++
+		break
+	}
+	if count != 1 {
+		t.Errorf("PrefixesOf early exit failed")
+	}
+
+	// 7. Set interface methods coverage
+	ss1 := NewSliceSet[byte]()
+	ss2 := NewSliceSet[byte]()
+	ss2.Add([]byte("a"))
+	ss2.Add([]byte("b"))
+
+	ss1.AddAll(ss2.All())
+	if !ss1.ContainsAll(ss2) {
+		t.Errorf("ContainsAll failed")
+	}
+
+	ss1.RemoveAll(ss2)
+	if ss1.Size() != 0 {
+		t.Errorf("RemoveAll failed")
+	}
+
+	ss1.Add([]byte("a"))
+	ss1.Add([]byte("b"))
+	ss1.Add([]byte("c"))
+	ss3 := NewSliceSet[byte]()
+	ss3.Add([]byte("a"))
+	ss1.RetainAll(ss3)
+	if ss1.Size() != 1 || !ss1.Contains([]byte("a")) {
+		t.Errorf("RetainAll failed")
+	}
+
+	ss1.RemoveElement([]byte("a"))
+	if ss1.Size() != 0 {
+		t.Errorf("Remove failed")
+	}
+
+	// String set methods
+	strSet1 := NewSet()
+	strSet2 := NewSet()
+	strSet2.Add("a")
+	strSet1.AddAll(strSet2.All())
+	if !strSet1.ContainsAll(strSet2) {
+		t.Errorf("ContainsAll string failed")
+	}
+
+	// 8. PrefixesOf missing cases
+	sm2 := NewSliceMap[byte, int]()
+	sm2.Put([]byte("a"), 1)
+	for range sm2.PrefixesOf([]byte("ab")) {
+	} // no break
+
+	sm3 := NewMap[int]()
+	sm3.Put("a", 1)
+	for range sm3.PrefixesOf("ab") {
+	} // no break
+
+	// 9. ShortestPrefixOf missing cases
+	sm2.ShortestPrefixOf([]byte("x"))
+	sm3.ShortestPrefixOf("x")
+}

trie/example_test.go

@@ -0,0 +1,74 @@
+package trie_test
+
+import (
+	"fmt"
+
+	"github.com/lock14/collections/trie"
+)
+
+func ExampleNewMap() {
+	m := trie.NewMap[int]()
+
+	m.Put("apple", 1)
+	m.Put("app", 2)
+	m.Put("ape", 3)
+	m.Put("bat", 4)
+
+	v, ok := m.Get("app")
+	fmt.Printf("Get('app'): %d, %v\n", v, ok)
+
+	fmt.Printf("Size: %d\n", m.Size())
+
+	// Output:
+	// Get('app'): 2, true
+	// Size: 4
+}
+
+func ExampleMap_KeysWithPrefix() {
+	m := trie.NewMap[int]()
+
+	m.Put("apple", 1)
+	m.Put("app", 2)
+	m.Put("ape", 3)
+	m.Put("bat", 4)
+
+	fmt.Println("Keys with prefix 'ap':")
+	for k := range m.KeysWithPrefix("ap") {
+		fmt.Println(k)
+	}
+
+	// Output:
+	// Keys with prefix 'ap':
+	// ape
+	// app
+	// apple
+}
+
+func ExampleMap_LongestPrefixOf() {
+	m := trie.NewMap[int]()
+
+	// E.g., setting up routing rules
+	m.Put("/api/", 1)
+	m.Put("/api/v1/", 2)
+	m.Put("/api/v1/users", 3)
+
+	query := "/api/v1/users/123/profile"
+	k, v, ok := m.LongestPrefixOf(query)
+	fmt.Printf("Matched route: %s (value %d, found %v)\n", k, v, ok)
+
+	// Output:
+	// Matched route: /api/v1/users (value 3, found true)
+}
+
+func ExampleNewSliceMap() {
+	m := trie.NewSliceMap[byte, string]()
+
+	m.Put([]byte{192, 168, 0, 1}, "router")
+	m.Put([]byte{192, 168, 0, 100}, "laptop")
+
+	k, v, ok := m.LongestPrefixOf([]byte{192, 168, 0, 100, 255})
+	fmt.Printf("Matched: %v -> %s (found: %v)\n", k, v, ok)
+
+	// Output:
+	// Matched: [192 168 0 100] -> laptop (found: true)
+}