Chapter ‍25 The standard library

This chapter describes the functions provided by the OCaml standard library. The modules from the standard library are automatically linked with the user’s object code files by the ocamlc command. Hence, these modules can be used in standalone programs without having to add any .cmo file on the command line for the linking phase. Similarly, in interactive use, these globals can be used in toplevel phrases without having to load any .cmo file in memory.

Unlike the core Stdlib module, submodules are not automatically “opened” when compilation starts, or when the toplevel system is launched. Hence it is necessary to use qualified identifiers to refer to the functions provided by these modules, or to add open directives.

Module Arg: parsing of command line arguments
Module Array: array operations
Module ArrayLabels: array operations (with labels)
Module Atomic: atomic references
Module Bigarray: large, multi-dimensional, numerical arrays
Module Bool: boolean values
Module Buffer: extensible buffers
Module Bytes: byte sequences
Module BytesLabels: byte sequences (with labels)
Module Callback: registering OCaml values with the C runtime
Module Char: character operations
Module Complex: complex numbers
Module Digest: MD5 message digest
Module Either: either values
Module Ephemeron: Ephemerons and weak hash table
Module Filename: operations on file names
Module Float: floating-point numbers
Module Format: pretty printing
Module Fun: function values
Module Gc: memory management control and statistics; finalized values
Module Genlex: a generic lexical analyzer
Module Hashtbl: hash tables and hash functions
Module Int: integers
Module Int32: 32-bit integers
Module Int64: 64-bit integers
Module Lazy: deferred computations
Module Lexing: the run-time library for lexers generated by ocamllex
Module List: list operations
Module ListLabels: list operations (with labels)
Module Map: association tables over ordered types
Module Marshal: marshaling of data structures
Module MoreLabels: include modules Hashtbl, Map and Set with labels
Module Nativeint: processor-native integers
Module Oo: object-oriented extension
Module Option: option values
Module Parsing: the run-time library for parsers generated by ocamlyacc
Module Printexc: facilities for printing exceptions
Module Printf: formatting printing functions
Module Queue: first-in first-out queues
Module Random: pseudo-random number generator (PRNG)
Module Result: result values
Module Scanf: formatted input functions
Module Seq: functional iterators
Module Set: sets over ordered types
Module Stack: last-in first-out stacks
Module StdLabels: include modules Array, List and String with labels
Module Stream: streams and parsers
Module String: string operations
Module StringLabels: string operations (with labels)
Module Sys: system interface
Module Uchar: Unicode characters
Module Unit: unit values
Module Weak: arrays of weak pointers