\chapter{The standard library} \label{c:stdlib}\cutname{stdlib.html}

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.

\label{stdlib:top}

\begin{latexonly}

\section*{s:stdlib-conv}{Conventions}

For easy reference, the modules are listed below in alphabetical order
of module names.
For each module, the declarations from its signature are printed
one by one in typewriter font, followed by a short comment.
All modules and the identifiers they export are indexed at the end of
this report.

\section*{s:stdlib-overview}{Overview}

Here is a short listing, by theme, of the standard library modules.

\subsubsection*{sss:stdlib-data-structures}{Data structures:}
\begin{tabular}{lll}
% Beware: these entries must be written in a very rigidly-defined
% format, or the check-stdlib-modules script will complain.
"String" & p.~\stdpageref{String} & string operations \\
"Bytes" & p.~\stdpageref{Bytes} & operations on byte sequences\\
"Array" & p.~\stdpageref{Array} & array operations \\
"List" & p.~\stdpageref{List} & list operations \\
"StdLabels" & p.~\stdpageref{StdLabels} & labelized versions of
the above 4 modules \\
"Unit" & p.~\stdpageref{Unit} & unit values \\
"Bool" & p.~\stdpageref{Bool} & boolean values \\
"Char" & p.~\stdpageref{Char} & character operations \\
"Uchar" & p.~\stdpageref{Uchar} & Unicode characters \\
"Int" & p.~\stdpageref{Int} & integer values \\
"Option" & p.~\stdpageref{Option} & option values \\
"Pair" & p.~\stdpageref{Pair} & pairs of values \\
"Result" & p.~\stdpageref{Result} & result values \\
"Effect" & p.~\stdpageref{Effect} & effect handlers \\
"Either" & p.~\stdpageref{Either} & either values \\
"Hashtbl" & p.~\stdpageref{Hashtbl} & hash tables and hash functions \\
"Random" & p.~\stdpageref{Random} & pseudo-random number generator \\
"Set" & p.~\stdpageref{Set} & sets over ordered types \\
"Map" & p.~\stdpageref{Map} & association tables over ordered types \\
"MoreLabels" & p.~\stdpageref{MoreLabels} & labelized versions of
"Hashtbl", "Set", and "Map" \\
"Oo" & p.~\stdpageref{Oo} & useful functions on objects \\
"Stack" & p.~\stdpageref{Stack} & last-in first-out stacks \\
"Queue" & p.~\stdpageref{Queue} & first-in first-out queues \\
"Pqueue" & p.~\stdpageref{Pqueue} & priority queues \\
"Buffer" & p.~\stdpageref{Buffer} & buffers that grow on demand \\
"Dynarray" & p.~\stdpageref{Dynarray} & dynamic arrays: arrays that grow on demand \\
"Seq" & p.~\stdpageref{Seq} & functional iterators \\
"Lazy" & p.~\stdpageref{Lazy} & delayed evaluation \\
"Weak" & p.~\stdpageref{Weak} & references that don't prevent objects
from being garbage-collected \\
"Atomic" & p.~\stdpageref{Atomic} & atomic references (for compatibility with concurrent runtimes) \\
"Ephemeron" & p.~\stdpageref{Ephemeron} & ephemerons and weak hash tables \\
"Bigarray" & p.~\stdpageref{Bigarray} & large, multi-dimensional, numerical arrays \\
"Iarray" & p.~\stdpageref{Iarray} & immutable arrays
\end{tabular}
\subsubsection*{sss:stdlib-arith}{Arithmetic:}
\begin{tabular}{lll}
"Complex" & p.~\stdpageref{Complex} & complex numbers \\
"Float" & p.~\stdpageref{Float} & floating-point numbers \\
"Int32" & p.~\stdpageref{Int32} & operations on 32-bit integers \\
"Int64" & p.~\stdpageref{Int64} & operations on 64-bit integers \\
"Nativeint" & p.~\stdpageref{Nativeint} & operations on platform-native
integers
\end{tabular}
\subsubsection*{sss:stdlib-io}{input/output:}
\begin{tabular}{lll}
"In_channel" & p.~\stdpageref{In_channel} & input channels \\
"Out_channel" & p.~\stdpageref{Out_channel} & output channels \\
"Format" & p.~\stdpageref{Format} & pretty printing with automatic
indentation and line breaking \\
"Marshal" & p.~\stdpageref{Marshal} & marshaling of data structures \\
"Printf" & p.~\stdpageref{Printf} & formatting printing functions \\
"Scanf" & p.~\stdpageref{Scanf} & formatted input functions \\
"Digest" & p.~\stdpageref{Digest} & MD5 message digest \\
\end{tabular}
\subsubsection*{sss:stdlib-parsing}{Parsing:}
\begin{tabular}{lll}
"Lexing" & p.~\stdpageref{Lexing} & the run-time library for lexers generated by "ocamllex" \\
"Parsing" & p.~\stdpageref{Parsing} & the run-time library for parsers generated by "ocamlyacc" \\
\end{tabular}
\subsubsection*{sss:stdlib-system}{System interface:}
\begin{tabular}{lll}
"Arg" & p.~\stdpageref{Arg} & parsing of command line arguments \\
"Callback" & p.~\stdpageref{Callback} & registering OCaml functions to
be called from C \\
"Filename" & p.~\stdpageref{Filename} & operations on file names \\
"Gc" & p.~\stdpageref{Gc} & memory management control and statistics \\
"Printexc" & p.~\stdpageref{Printexc} & a catch-all exception handler \\
"Sys" & p.~\stdpageref{Sys} & system interface \\
\end{tabular}
\subsubsection*{sss:stdlib-multicore}{Multicore interface:}
\begin{tabular}{lll}
"Domain" & p.~\stdpageref{Domain} & domain spawn and join \\
"Mutex" & p.~\stdpageref{Mutex} & mutual exclusion locks \\
"Condition" & p.~\stdpageref{Condition} & condition variables \\
"Semaphore" & p.~\stdpageref{Semaphore} & semaphores \\
"Effect" & p.~\stdpageref{Effect} & deep and shallow effect handlers \\
\end{tabular}
\subsubsection*{sss:stdlib-misc}{Misc:}
\begin{tabular}{lll}
"Fun" & p.~\stdpageref{Fun} & function values \\
"Type" & p.~\stdpageref{Type} & type introspection \\
"Repr" & p.~\stdpageref{Repr} & functions defined on the low-level
representation of values \\
\end{tabular}
\end{latexonly}

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