# Mmap
**Module**: `rustkmer::io::mmap`
## Overview
Memory-mapped file operations
Provides memory-mapped file reading for large genomic datasets.
## API Reference
### Fns
#### as_slice
```rust
pub fn as_slice(&self) -> &[u8] {
```
Get a slice of the memory-mapped data
# Returns
Slice of the file contents
#### len
```rust
pub fn len(&self) -> usize {
```
Get length of the mapped file
# Returns
File length in bytes
#### is_empty
```rust
pub fn is_empty(&self) -> bool {
```
Check if the file is empty
# Returns
True if file is empty
#### lines
```rust
pub fn lines(&self) -> impl Iterator<Item = &[u8]> + '_ {
```
Get an iterator over lines in the file
# Returns
Iterator over line slices
#### read_to_string
```rust
pub fn read_to_string(&self) -> Result<String, std::string::FromUtf8Error> {
```
Read file into a String (for smaller files)
# Returns
String containing file contents
---
*Source: [`mmap.rs`](../../../io/mmap.rs)*