# Batteries user guide

OCaml Batteries Included documentation.

OCaml Batteries included (or simply "Batteries") is a community-driven effort to standardize on an consistent, documented, and comprehensive development platform for the OCaml programming language.

For the moment, Batteries Included concentrates on:

- data structures
- file manipulation
- inputs and outputs
- concurrency
- numbers
- text, including Unicode

For more information on the installation of Batteries Included, please read the Installation guide and for an example using it in different build systems, we have the Getting started manual.

Do you have suggestions? Remarks? Bug reports ? To contact us or to be kept informed, don't hesitate to visit our website, Git repo, and our Issue tracker.

###### New Data Structures in Batteries

BatBitSet | Efficient bit sets.
BatCache | The data structure for a manual cache with keys `'a` and values `'b`.
BatDeque | Functional double-ended queues
BatDllist | A mutable, imperative, circular, doubly linked list library
BatDynArray | Dynamic arrays.
BatEnum | Enumeration over abstract collection of elements.
BatFingerTree | This module implements a generic finger tree datastructure as described here: Finger Trees: A Simple General-purpose Data Structure http://www.soi.city.ac.uk/~ross/papers/FingerTree.pdf
BatGlobal | Mutable global variable.
BatHashcons | Hash consing of data structures
BatHeap | Functional heaps over ordered types
BatIMap | DIET Maps from integers, packed using ranges
BatISet | DIET : Discrete Interval Encoding Trees
BatLazyList | Lazy lists of elements.
BatMultiPMap | Polymorphic Multi-Map.
BatRefList | Reference on lists.
BatSeq | Sequence of elements
BatSplay | Maps and sets based on splay trees
BatUref | Unifiable references using destructive union-find
BatVect | Extensible vectors with constant-time append/prepend.

###### New Modules in Batteries

BatBase64 | Base64 codec.
BatCharParser | Parsing character strings.
BatFile | File manipulation.
BatInterfaces | Common signatures for data structures.
BatIO | High-order abstract I/O.
BatLog | Simple logging
BatLogger | Logging Library
BatNumber | A common interface for numbers.
BatOptParse | Modules for GNU `getopt(3)`-style command line parsing.
BatParserCo | A simple parser combinator library.
BatResult | Monadic results of computations that can raise exceptions
BatReturn | Local exceptions/labels/goto/return.

###### Builtin Types as Modules

BatBool | Operations on booleans
BatChar | Operations on characters.
BatFloat | Operations on floating-point numbers.
BatInt | Operations on integers.
BatInt32 | 32-bit integers.
BatInt64 | 64-bit integers.
BatNativeint | Processor-native integers.
BatOption | Functions for the option type.
BatRef | Operations on references.
BatTuple | Tuples.
BatUnit | Operations on `unit`.

###### Extensions to the Standard Library

These modules have base library equivalents. When using `open Batteries`, `BatFoo` will replace `Foo`, so that the new functions are easily available without a `Bat` prefix on the module name. As well, `BatPervasives` is opened into the global namespace. Finally, the previous versions of replaced modules are available in the `Legacy` module, i.e. `Legacy.Unix` and `Legacy.Pervasives`.

BatArray | Array operations
BatBigarray | Additional and modified functions for big arrays.
BatBig_int | Operations on arbitrary-precision integers.
BatBuffer | Extensible string buffers.
BatComplex | Additional and modified functions for complex numbers.
BatDigest | MD5 message digest.
BatFormat | Pretty printing.
BatGc | Memory management control and statistics; finalised values.
BatGenlex | A generic lexical analyzer.
BatHashtbl | Extra functions over hashtables.
BatLexing | Simple lexing using ocaml conventions
BatList | Additional and modified functions for lists.
BatMap | Association tables over ordered types.
BatMarshal | Marshaling of data structures.
BatNum | Operation on arbitrary-precision numbers.
BatOo | Operations on objects
BatPervasives | Additional functions.
BatPrintexc | Facilities for printing exceptions.
BatPrintf | Formatted output functions (also known as unparsing).
BatQueue | First-in first-out queues.
BatRandom | Pseudo-random number generators (PRNG).
BatScanf | Formatted input functions.
BatSet | Sets over ordered types.
BatStack | Last-in first-out stacks.
BatStream | Streams and stream parsers
BatString | String operations.
BatSys | System interface.
BatUnix | Low-level interface to the operating system (both Unix and Windows).

###### Thread-related Modules

These modules are available only when compiling with threads. To use them, do `open BatteriesThread` at the top of your code.

BatConcurrent | Definition of concurrency primitives.
BatMutex | Locks for mutual exclusion.
BatRMutex | Reentrant Mutexes

###### Incubator

These modules are available only inside `Batteries.Incubator`. Their interface is not guaranteed stable, and may be changed at any time, including with backwards incompatible changes between point releases. They are included for testing and stabilization until they can be finalized and moved to batteries proper.

BatBounded | Bounded values
BatOrd | An algebraic datatype for ordering.
BatPathGen | Filepath handling.
BatSubstring | `Substring.t` is the type of substrings of a basestring, an efficient representation of a piece of a string.

###### Internal Modules

BatAvlTree | Internals of ISet and IMap, usable as generic tree library
BatInnerIO | Core of the BatIO module.
BatInnerWeaktbl | Weak hash table library for OCaml, with an interface compatible with the standard Hashtbl module.