<s>
PureScript	B-Language
is	O
a	O
strongly-typed	O
,	O
purely-functional	B-Application
programming	O
language	O
that	O
transpiles	B-Language
to	O
JavaScript	B-Language
,	O
C++11	B-Language
,	O
and	O
Go	B-Application
.	O
</s>
<s>
It	O
can	O
be	O
used	O
to	O
develop	O
web	O
applications	O
,	O
server	O
side	O
apps	O
,	O
and	O
also	O
desktop	O
applications	O
with	O
use	O
of	O
Electron	B-Operating_System
or	O
via	O
C++11	B-Language
and	O
Go	B-Application
compilers	O
with	O
suitable	O
libraries	O
.	O
</s>
<s>
Its	O
syntax	O
is	O
mostly	O
comparable	O
to	O
that	O
of	O
Haskell	B-Language
.	O
</s>
<s>
In	O
addition	O
,	O
it	O
introduces	O
row	O
polymorphism	O
and	O
extensible	B-Application
records	I-Application
.	O
</s>
<s>
Also	O
,	O
contrary	O
to	O
Haskell	B-Language
,	O
the	O
PureScript	B-Language
language	O
is	O
defined	O
as	O
having	O
a	O
strict	O
evaluation	O
strategy	O
,	O
although	O
there	O
are	O
non-conforming	O
back	O
ends	O
which	O
implement	O
a	O
lazy	O
evaluation	O
strategy	O
.	O
</s>
<s>
PureScript	B-Language
was	O
initially	O
designed	O
by	O
Phil	O
Freeman	O
in	O
2013	O
.	O
</s>
<s>
He	O
started	O
to	O
work	O
on	O
PureScript	B-Language
since	O
he	O
was	O
n't	O
satisfied	O
by	O
other	O
attempts	O
to	O
transpile	B-Language
Haskell	B-Language
to	O
JavaScript	B-Language
(	O
e.g.	O
</s>
<s>
Since	O
then	O
it	O
has	O
been	O
picked	O
up	O
by	O
the	O
community	O
and	O
is	O
developed	O
on	O
GitHub	B-Application
.	O
</s>
<s>
PureScript	B-Language
features	O
strict	O
evaluation	O
,	O
persistent	B-Application
data	I-Application
structures	I-Application
and	O
type	O
inference	O
.	O
</s>
<s>
The	O
PureScript	B-Language
type	O
system	O
shares	O
many	O
features	O
with	O
those	O
of	O
similar	O
functional	B-Language
languages	I-Language
like	O
Haskell	B-Language
:	O
algebraic	O
data	O
types	O
and	O
pattern	B-Language
matching	I-Language
,	O
higher	O
kinded	O
types	O
,	O
type	O
classes	O
and	O
functional	B-Language
dependencies	O
,	O
and	O
higher-rank	O
polymorphism	O
.	O
</s>
<s>
PureScript	B-Language
's	O
type	O
system	O
adds	O
support	O
for	O
row	O
polymorphism	O
and	O
extensible	B-Application
records	I-Application
.	O
</s>
<s>
However	O
,	O
PureScript	B-Language
lacks	O
support	O
for	O
some	O
of	O
the	O
more	O
advanced	O
features	O
of	O
Haskell	B-Language
like	O
GADTs	B-Application
and	O
type	O
families	O
.	O
</s>
<s>
The	O
PureScript	B-Language
transpilers	B-Language
attempt	O
to	O
produce	O
readable	O
code	O
,	O
where	O
possible	O
.	O
</s>
<s>
Through	O
a	O
simple	O
FFI	B-Application
interface	I-Application
,	O
it	O
also	O
allows	O
the	O
reuse	O
of	O
existing	O
JavaScript/C	O
++	O
11/Go	O
code	O
.	O
</s>
<s>
PureScript	B-Language
supports	O
incremental	B-Application
compilation	I-Application
,	O
and	O
the	O
transpiler	B-Language
to	O
JavaScript	B-Language
distribution	O
includes	O
support	O
for	O
building	O
source	B-Application
code	I-Application
editor	I-Application
plugins	O
for	O
iterative	O
development	O
.	O
</s>
<s>
Editor	O
plugins	O
exist	O
for	O
many	O
popular	O
text	O
editors	O
,	O
including	O
Vim	B-Application
,	O
Emacs	B-Application
,	O
Sublime	B-Language
Text	I-Language
,	O
Atom	B-Application
and	O
Visual	B-Language
Studio	I-Language
Code	I-Language
.	O
</s>
<s>
PureScript	B-Language
supports	O
type-driven	O
development	O
via	O
its	O
typed	O
holes	O
feature	O
,	O
in	O
which	O
a	O
program	O
can	O
be	O
constructed	O
with	O
missing	O
subexpressions	O
.	O
</s>
<s>
The	O
JavaScript	B-Language
transpiler	B-Language
will	O
subsequently	O
attempt	O
to	O
infer	O
the	O
types	O
of	O
the	O
missing	O
subexpressions	O
,	O
and	O
report	O
those	O
types	O
to	O
the	O
user	O
.	O
</s>
<s>
This	O
feature	O
has	O
inspired	O
similar	O
work	O
in	O
the	O
GHC	B-Application
Haskell	I-Application
compiler	O
.	O
</s>
<s>
Here	O
is	O
a	O
minimal	O
"	O
Hello	O
world	O
"	O
program	O
in	O
PureScript	B-Language
:	O
</s>
<s>
Here	O
,	O
the	O
type	O
of	O
the	O
program	O
is	O
inferred	O
and	O
checked	O
by	O
the	O
PureScript	B-Language
transpiler	B-Language
.	O
</s>
