<s>
F#	O
(	O
pronounced	O
F	B-Operating_System
sharp	I-Operating_System
)	O
is	O
a	O
functional-first	O
,	O
general-purpose	B-Language
,	O
strongly	O
typed	O
,	O
multi-paradigm	O
programming	O
language	O
that	O
encompasses	O
functional	B-Language
,	O
imperative	B-Application
,	O
and	O
object-oriented	B-Language
programming	I-Language
methods	O
.	O
</s>
<s>
It	O
is	O
most	O
often	O
used	O
as	O
a	O
cross-platform	B-Operating_System
Common	O
Language	O
Infrastructure	O
(	O
CLI	O
)	O
language	O
on	O
.NET	B-Application
,	O
but	O
can	O
also	O
generate	O
JavaScript	B-Language
and	O
graphics	B-Architecture
processing	I-Architecture
unit	I-Architecture
(	O
GPU	B-Architecture
)	O
code	O
.	O
</s>
<s>
F#	O
is	O
developed	O
by	O
the	B-Application
F#	I-Application
Software	I-Application
Foundation	I-Application
,	O
Microsoft	O
and	O
open	O
contributors	O
.	O
</s>
<s>
An	O
open	B-License
source	I-License
,	O
cross-platform	B-Operating_System
compiler	O
for	O
F#	O
is	O
available	O
from	O
the	B-Application
F#	I-Application
Software	I-Application
Foundation	I-Application
.	O
</s>
<s>
F#	O
is	O
a	O
fully	O
supported	O
language	O
in	O
Visual	B-Application
Studio	I-Application
and	O
JetBrains	O
Rider	O
.	O
</s>
<s>
Plug-ins	B-Application
supporting	O
F#	O
exist	O
for	O
many	O
widely	O
used	O
editors	O
including	O
Visual	B-Language
Studio	I-Language
Code	I-Language
,	O
Vim	B-Application
,	O
and	O
Emacs	B-Application
.	O
</s>
<s>
F#	O
is	O
a	O
member	O
of	O
the	O
ML	B-Language
language	I-Language
family	O
and	O
originated	O
as	O
a	O
.NET	B-Application
Framework	I-Application
implementation	O
of	O
a	O
core	O
of	O
the	O
programming	O
language	O
OCaml	B-Language
.	O
</s>
<s>
It	O
has	O
also	O
been	O
influenced	O
by	O
C#	B-Application
,	O
</s>
<s>
Python	B-Language
,	O
Haskell	B-Language
,	O
Scala	B-Application
and	O
Erlang	B-Operating_System
.	O
</s>
<s>
Version	O
Language	O
specification	O
Date	O
Platforms	B-Device
Runtime	B-Device
F#	O
1.x	O
May	O
2005Windows.NET	O
1.0	O
-	O
3.5	O
F#	O
2.0	O
August	O
2010	O
April	O
2010Linux	O
,	O
macOS	B-Application
,	O
Windows	B-Application
.NET	B-Application
2.0	O
-	O
4.0	O
,	O
Mono	B-Application
F#	O
3.0	O
November	O
2012	O
August	O
2012Linux	O
,	O
macOS	B-Application
,	O
Windows	B-Application
;	O
JavaScript	B-Language
,	O
GPU.NET	O
2.0	O
-	O
4.5	O
,	O
Mono	B-Application
F#	O
3.1	O
November	O
2013	O
October	O
2013Linux	O
,	O
macOS	B-Application
,	O
Windows	B-Application
;	O
JavaScript	B-Language
,	O
GPU.NET	O
2.0	O
-	O
4.5	O
,	O
Mono	B-Application
F#	O
4.0	O
January	O
2016	O
July	O
2015F#	O
4.1	O
May	O
2018March	O
2017Linux	O
,	O
macOS	B-Application
,	O
Windows	B-Application
,	O
</s>
<s>
JavaScript	B-Language
,	O
GPU.NET	O
3.5	O
-	O
4.6.2	O
,	O
.NET	B-Application
Core	I-Application
,	O
MonoF#	O
4.5August	O
2018Linux	O
,	O
macOS	B-Application
,	O
Windows	B-Application
,	O
</s>
<s>
JavaScript	B-Language
,	O
GPU	B-Architecture
.NET	B-Application
4.5	O
-	O
4.7.2	O
,	O
.NET	B-Application
Core	I-Application
SDK	O
2.1.400F	O
#	O
4.6March	O
2019Linux	O
,	O
macOS	B-Application
,	O
Windows	B-Application
,	O
</s>
<s>
JavaScript	B-Language
,	O
GPU	B-Architecture
.NET	B-Application
4.5	O
-	O
4.7.2	O
,	O
.NET	B-Application
Core	I-Application
SDK	O
2.2.300F	O
#	O
4.7September	O
2019Linux	O
,	O
macOS	B-Application
,	O
Windows	B-Application
,	O
</s>
<s>
JavaScript	B-Language
,	O
GPU	B-Architecture
.NET	B-Application
4.5	O
-	O
4.8	O
,	O
.NET	B-Application
Core	I-Application
SDK	O
3.0.100F	O
#	O
5.0November	O
2020Linux	O
,	O
macOS	B-Application
,	O
Windows	B-Application
,	O
</s>
<s>
JavaScript	B-Language
,	O
GPU	B-Architecture
.NET	B-Application
SDK	I-Application
5.0.100F	O
#	O
6.0November	O
2021Linux	O
,	O
macOS	B-Application
,	O
Windows	B-Application
,	O
</s>
<s>
JavaScript	B-Language
,	O
GPU	B-Architecture
.NET	B-Application
SDK	I-Application
6.0.100F	O
#	O
7.0November	O
2022Linux	O
,	O
macOS	B-Application
,	O
Windows	B-Application
,	O
</s>
<s>
F#	O
uses	O
an	O
open	B-License
development	I-License
and	O
engineering	O
process	O
.	O
</s>
<s>
The	O
language	O
evolution	O
process	O
is	O
managed	O
by	O
Don	O
Syme	O
from	O
Microsoft	O
Research	O
as	O
the	O
benevolent	O
dictator	O
for	O
life	O
(	O
BDFL	O
)	O
for	O
the	O
language	O
design	O
,	O
together	O
with	O
the	B-Application
F#	I-Application
Software	I-Application
Foundation	I-Application
.	O
</s>
<s>
F#	O
was	O
first	O
included	O
in	O
Visual	B-Application
Studio	I-Application
in	O
the	O
2010	O
edition	O
,	O
at	O
the	O
same	O
level	O
as	O
Visual	O
Basic	O
and	O
C#	B-Application
(	O
albeit	O
as	O
an	O
option	O
)	O
,	O
and	O
has	O
remained	O
in	O
subsequent	O
editions	O
,	O
thus	O
making	O
the	O
language	O
widely	O
available	O
and	O
well-supported	O
.	O
</s>
<s>
The	O
language	O
was	O
originally	O
designed	O
and	O
implemented	O
by	O
Don	O
Syme	O
,	O
according	O
to	O
whom	O
in	O
the	O
fsharp	B-Operating_System
team	O
,	O
they	O
say	O
the	O
F	O
is	O
for	O
"	O
Fun	O
"	O
.	O
</s>
<s>
The	O
Visual	O
F#	O
Tools	O
for	O
Visual	B-Application
Studio	I-Application
are	O
developed	O
by	O
Microsoft	O
.	O
</s>
<s>
The	B-Application
F#	I-Application
Software	I-Application
Foundation	I-Application
developed	O
the	O
F#	O
open-source	B-License
compiler	O
and	O
tools	O
,	O
incorporating	O
the	O
open-source	B-License
compiler	O
implementation	O
provided	O
by	O
the	O
Microsoft	O
Visual	O
F#	O
Tools	O
team	O
.	O
</s>
<s>
Added	O
support	O
for	O
N-d	O
arrays	B-Data_Structure
up	O
to	O
rank	O
32	O
.	O
</s>
<s>
While	O
supporting	O
object-oriented	B-Language
features	O
available	O
in	O
C#	B-Application
,	O
F#	O
is	O
a	O
strongly	O
typed	O
functional-first	O
language	O
with	O
a	O
large	O
number	O
of	O
capabilities	O
that	O
are	O
normally	O
found	O
only	O
in	O
functional	B-Language
programming	I-Language
languages	I-Language
.	O
</s>
<s>
Together	O
,	O
these	O
features	O
allow	O
F#	O
programs	O
to	O
be	O
written	O
in	O
a	O
completely	O
functional	B-Language
style	O
and	O
also	O
allow	O
functional	B-Language
and	O
object-oriented	B-Language
styles	O
to	O
be	O
mixed	O
.	O
</s>
<s>
Examples	O
of	O
functional	B-Language
features	O
are	O
:	O
</s>
<s>
For	O
functional	B-Language
programming	I-Language
,	O
F#	O
provides	O
tuple	O
,	O
record	O
,	O
discriminated	B-Language
union	I-Language
,	O
list	O
,	O
option	O
,	O
and	O
result	O
types	O
.	O
</s>
<s>
A	O
discriminated	B-Language
union	I-Language
type	O
is	O
a	O
type-safe	B-Language
version	O
of	O
C	O
unions	O
.	O
</s>
<s>
The	O
list	O
type	O
is	O
an	O
immutable	O
linked	B-Data_Structure
list	I-Data_Structure
represented	O
either	O
using	O
a	O
notation	O
(	O
:	O
:	O
is	O
the	O
cons	B-Protocol
operator	O
)	O
or	O
a	O
shorthand	O
as	O
.	O
</s>
<s>
The	O
option	O
type	O
is	O
a	O
discriminated	B-Language
union	I-Language
type	O
with	O
choices	O
Some(x )	O
or	O
None	O
.	O
</s>
<s>
F#	O
types	O
may	O
be	O
generic	B-Language
,	O
implemented	O
as	O
generic	B-Language
.NET	B-Application
types	O
.	O
</s>
<s>
F#	O
supports	O
lambda	B-Language
functions	I-Language
and	O
closures	B-Language
.	O
</s>
<s>
Functions	O
can	O
be	O
curried	B-Application
.	O
</s>
<s>
Like	O
other	O
functional	B-Language
programming	I-Language
languages	I-Language
,	O
F#	O
allows	O
function	B-Application
composition	I-Application
using	O
the	O
>>	O
and	O
<<	O
operators	O
.	O
</s>
<s>
Sequences	O
are	O
generators	O
–	O
values	O
are	O
generated	O
on-demand	O
(	O
i.e.	O
,	O
are	O
lazily	O
evaluated	O
)	O
–	O
while	O
lists	O
and	O
arrays	B-Data_Structure
are	O
evaluated	O
eagerly	O
.	O
</s>
<s>
F#	O
uses	O
pattern	B-Language
matching	I-Language
to	O
bind	O
values	O
to	O
names	O
.	O
</s>
<s>
Pattern	B-Language
matching	I-Language
is	O
also	O
used	O
when	O
accessing	O
discriminated	O
unions	O
–	O
the	O
union	O
is	O
value	O
matched	O
against	O
pattern	O
rules	O
and	O
a	O
rule	O
is	O
selected	O
when	O
a	O
match	O
succeeds	O
.	O
</s>
<s>
F#	O
also	O
supports	O
Active	O
Patterns	O
as	O
a	O
form	O
of	O
extensible	O
pattern	B-Language
matching	I-Language
.	O
</s>
<s>
hash	B-Application
table	I-Application
,	O
created	O
with	O
the	O
dict	O
[	O
...	O
]	O
syntax	O
or	O
System.Collections.Generic.Dictionaryxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx1	O
type	O
.	O
</s>
<s>
Also	O
,	O
F#	O
supports	O
access	O
to	O
all	O
CLI	O
types	O
and	O
objects	O
such	O
as	O
those	O
defined	O
in	O
the	O
System.Collections.Generic	O
namespace	O
defining	O
imperative	B-Application
data	O
structures	O
.	O
</s>
<s>
Like	O
other	O
Common	O
Language	O
Infrastructure	O
(	O
CLI	O
)	O
languages	O
,	O
F#	O
can	O
use	O
CLI	O
types	O
through	O
object-oriented	B-Language
programming	I-Language
.	O
</s>
<s>
F#	O
support	O
for	O
object-oriented	B-Language
programming	I-Language
in	O
expressions	O
includes	O
:	O
</s>
<s>
F#	O
object	O
type	O
definitions	O
can	O
be	O
class	O
,	O
struct	B-Application
,	O
interface	O
,	O
enum	O
,	O
or	O
delegate	O
type	O
definitions	O
,	O
corresponding	O
to	O
the	O
definition	O
forms	O
found	O
in	O
C#	B-Application
.	O
</s>
<s>
F#	O
supports	O
asynchronous	B-Operating_System
programming	I-Operating_System
through	O
asynchronous	O
workflows	O
.	O
</s>
<s>
Inversion	B-Language
of	I-Language
control	I-Language
in	O
F#	O
follows	O
this	O
pattern	O
.	O
</s>
<s>
Parallel	O
programming	O
is	O
also	O
supported	O
through	O
the	O
Array.Parallel	O
functional	B-Language
programming	I-Language
operators	O
in	O
the	O
F#	O
standard	O
library	O
,	O
direct	O
use	O
of	O
the	O
System.Threading.Tasks	O
task	O
programming	O
model	O
,	O
the	O
direct	O
use	O
of	O
.NET	B-Application
thread	O
pool	O
and	O
.NET	B-Application
threads	O
and	O
through	O
dynamic	O
translation	O
of	O
F#	O
code	O
to	O
alternative	O
parallel	O
execution	O
engines	O
such	O
as	O
GPU	B-Architecture
code	O
.	O
</s>
<s>
F#	O
allows	O
some	O
forms	O
of	O
syntax	O
customizing	O
via	O
metaprogramming	B-Application
to	O
support	O
embedding	O
custom	O
domain-specific	B-Language
languages	I-Language
within	O
the	O
F#	O
language	O
,	O
particularly	O
through	O
computation	O
expressions	O
.	O
</s>
<s>
F#	O
includes	O
a	O
feature	O
for	O
run-time	O
meta-programming	B-Application
called	O
quotations	O
.	O
</s>
<s>
F#	O
quotations	O
are	O
used	O
for	O
various	O
purposes	O
including	O
to	O
compile	O
F#	O
code	O
into	O
JavaScript	B-Language
and	O
GPU	B-Architecture
code	O
.	O
</s>
<s>
F#	O
3.0	O
introduced	O
a	O
form	O
of	O
compile-time	O
meta-programming	B-Application
through	O
statically	O
extensible	O
type	O
generation	O
called	O
F#	O
type	O
providers	O
.	O
</s>
<s>
In	O
F#	O
3.0	O
the	O
F#	O
quotation	O
and	O
computation	O
expression	O
features	O
are	O
combined	O
to	O
implement	O
LINQ	B-Language
queries	O
.	O
</s>
<s>
The	O
combination	O
of	O
type	O
providers	O
,	O
queries	O
and	O
strongly	O
typed	O
functional	B-Language
programming	I-Language
is	O
known	O
as	O
information	O
rich	O
programming	O
.	O
</s>
<s>
F#	O
supports	O
a	O
variation	O
of	O
the	O
Actor	B-Application
programming	O
model	O
through	O
the	O
in-memory	O
implementation	O
of	O
lightweight	O
asynchronous	O
agents	O
.	O
</s>
<s>
Visual	B-Application
Studio	I-Application
,	O
with	O
the	O
Visual	O
F#	O
tools	O
from	O
Microsoft	O
installed	O
,	O
can	O
be	O
used	O
to	O
create	O
,	O
run	O
and	O
debug	O
F#	O
projects	O
.	O
</s>
<s>
The	O
Visual	O
F#	O
tools	O
include	O
a	O
Visual	O
Studio-hosted	O
read	B-Application
–	I-Application
eval	I-Application
–	I-Application
print	I-Application
loop	I-Application
(	O
REPL	B-Application
)	O
interactive	O
console	O
that	O
can	O
execute	O
F#	O
code	O
as	O
it	O
is	O
written	O
.	O
</s>
<s>
Visual	B-Application
Studio	I-Application
for	O
Mac	O
also	O
fully	O
supports	O
F#	O
projects	O
.	O
</s>
<s>
Visual	B-Language
Studio	I-Language
Code	I-Language
contains	O
full	O
support	O
for	O
F#	O
via	O
the	O
.	O
</s>
<s>
Specific	O
support	O
exists	O
in	O
editors	O
such	O
as	O
Emacs	B-Application
.	O
</s>
<s>
LINQPad	B-General_Concept
has	O
supported	O
F#	O
since	O
version	O
2.x	O
.	O
</s>
<s>
F#	O
is	O
a	O
general-purpose	B-Language
programming	I-Language
language	I-Language
.	O
</s>
<s>
It	O
uses	O
ASP.NET	B-Application
Core	I-Application
on	O
the	O
server	O
side	O
and	O
on	O
the	O
client	O
side	O
.	O
</s>
<s>
An	O
alternative	O
end-to-end	O
F#	O
option	O
is	O
the	O
WebSharper	B-Application
framework	O
.	O
</s>
<s>
F#	O
can	O
be	O
used	O
together	O
with	O
the	O
to	O
develop	O
apps	O
for	O
iOS	B-Application
and	O
Android	B-Application
.	O
</s>
<s>
The	O
library	O
provides	O
a	O
more	O
comfortable	O
functional	B-Language
interface	O
.	O
</s>
<s>
Among	O
others	O
,	O
F#	O
is	O
used	O
for	O
quantitative	O
finance	O
programming	O
,	O
energy	O
trading	O
and	O
portfolio	O
optimization	O
,	O
machine	O
learning	O
,	O
business	O
intelligence	O
and	O
social	O
gaming	O
on	O
Facebook	B-Application
.	I-Application
</s>
<s>
In	O
the	O
2010s	O
,	O
F#	O
has	O
been	O
positioned	O
as	O
an	O
optimized	O
alternative	O
to	O
C#	B-Application
.	O
</s>
<s>
F#	O
can	O
be	O
used	O
as	O
a	O
scripting	O
language	O
,	O
mainly	O
for	O
desktop	O
read	B-Application
–	I-Application
eval	I-Application
–	I-Application
print	I-Application
loop	I-Application
(	O
REPL	B-Application
)	O
scripting	O
.	O
</s>
<s>
The	O
F#	O
open-source	B-License
community	O
includes	O
the	B-Application
F#	I-Application
Software	I-Application
Foundation	I-Application
and	O
the	O
F#	O
Open	B-License
Source	I-License
Group	O
at	O
GitHub	B-Application
.	O
</s>
<s>
Popular	O
open-source	B-License
F#	O
projects	O
include	O
:	O
</s>
<s>
,	O
an	O
F#	O
to	O
Javascript	B-Language
transpiler	O
based	O
on	O
.	O
</s>
<s>
,	O
an	O
alternative	O
package	O
manager	O
for	O
.NET	B-Application
that	O
can	O
still	O
use	O
NuGet	B-Application
repositories	O
,	O
but	O
has	O
centralised	O
version-management	O
.	O
</s>
<s>
,	O
a	O
functionally	O
oriented	O
middleware	O
for	O
ASP.NET	B-Application
Core	I-Application
.	O
</s>
<s>
F#	O
features	O
a	O
legacy	O
"	O
ML	B-Algorithm
compatibility	O
mode	O
"	O
that	O
can	O
directly	O
compile	O
programs	O
written	O
in	O
a	O
large	O
subset	O
of	O
OCaml	B-Language
roughly	O
,	O
with	O
no	O
functors	O
,	O
objects	O
,	O
polymorphic	O
variants	O
,	O
or	O
other	O
additions	O
.	O
</s>
<s>
A	O
simple	O
example	O
that	O
is	O
often	O
used	O
to	O
demonstrate	O
the	O
syntax	O
of	O
functional	B-Language
languages	I-Language
is	O
the	O
factorial	O
function	O
for	O
non-negative	O
32-bit	O
integers	O
,	O
here	O
shown	O
in	O
F#	O
:	O
</s>
<s>
A	O
sample	O
Windows	B-Application
Forms	O
program	O
:	O
</s>
