diff --git a/README.md b/README.md
index ecfa696..c2e2ffc 100644
--- a/README.md
+++ b/README.md
@@ -24,6 +24,6 @@ repositories {
 }
 
 dependencies {
-    implementation("me.alex_s168:blitz:0.1")
+    implementation("me.alex_s168:blitz:0.5")
 }
 ```
\ No newline at end of file
diff --git a/build.gradle.kts b/build.gradle.kts
index 5517be4..7f944e7 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -5,7 +5,7 @@ plugins {
 }
 
 group = "me.alex_s168"
-version = "0.3"
+version = "0.5"
 
 repositories {
     mavenCentral()
diff --git a/src/main/kotlin/blitz/IO.kt b/src/main/kotlin/blitz/IO.kt
new file mode 100644
index 0000000..41f69b1
--- /dev/null
+++ b/src/main/kotlin/blitz/IO.kt
@@ -0,0 +1,5 @@
+package blitz
+
+fun warn(msg: String) {
+    System.err.println(msg)
+}
\ No newline at end of file
diff --git a/src/main/kotlin/blitz/collections/BatchedUtils.kt b/src/main/kotlin/blitz/collections/BatchedUtils.kt
index f337239..5cff024 100644
--- a/src/main/kotlin/blitz/collections/BatchedUtils.kt
+++ b/src/main/kotlin/blitz/collections/BatchedUtils.kt
@@ -7,4 +7,12 @@ fun ByteBatchSequence.stringify(batch: Int = 64): Sequence<String> {
             iter.nextBytes(batch).decodeToString()
         else null
     }
+}
+
+fun Sequence<String>.flatten(): String {
+    val out = StringBuilder()
+    forEach {
+        out.append(it)
+    }
+    return out.toString()
 }
\ No newline at end of file
diff --git a/src/main/kotlin/blitz/io/Path.kt b/src/main/kotlin/blitz/io/Path.kt
index c034cc5..aea26ce 100644
--- a/src/main/kotlin/blitz/io/Path.kt
+++ b/src/main/kotlin/blitz/io/Path.kt
@@ -84,7 +84,7 @@ value class Path(
             if (path.isEmpty()) return Path(emptyArray())
             val kx = kotlinx.io.files.Path(path)
             if (kx.isAbsolute)
-                return Path(path.substring(1).split(separator).toTypedArray())
+                return Path(path.split(separator, '/', '\\').filterNot { it.isEmpty() }.toTypedArray())
             return of(SystemFileSystem.resolve(kx).toString())
         }
     }
diff --git a/src/main/kotlin/blitz/str/SplitWithNesting.kt b/src/main/kotlin/blitz/str/SplitWithNesting.kt
new file mode 100644
index 0000000..0b8748b
--- /dev/null
+++ b/src/main/kotlin/blitz/str/SplitWithNesting.kt
@@ -0,0 +1,33 @@
+package blitz.str
+
+fun String.splitWithNesting(
+    delim: Char,
+    nestUp: Char,
+    nestDown: Char,
+    dest: MutableList<String> = mutableListOf()
+): MutableList<String> {
+    val last = StringBuilder()
+    val iter = iterator()
+    var nesting = 0
+    while (iter.hasNext()) {
+        val c = iter.next()
+        if (nesting == 0 && c == delim) {
+            dest.add(last.toString())
+            last.clear()
+        } else if (c == nestUp) {
+            nesting ++
+            last.append(c)
+        } else if (c == nestDown) {
+            if (nesting == 0)
+                throw Exception("Unmatched $nestDown")
+            nesting --
+            last.append(c)
+        } else {
+            last.append(c)
+        }
+    }
+    dest.add(last.toString())
+    if (nesting != 0)
+        throw Exception("Unmatched $nestUp")
+    return dest
+}
\ No newline at end of file