<s>
Store-passing	B-Application
style	I-Application
is	O
a	O
programming	O
technique	O
that	O
is	O
used	O
to	O
model	O
mutable	B-Application
state	I-Application
without	O
using	O
mutable	B-Application
state	I-Application
.	O
</s>
<s>
It	O
generally	O
arises	O
in	O
the	O
conversion	O
of	O
imperative	B-Application
programs	I-Application
into	O
purely	B-Application
functional	I-Application
ones	O
.	O
</s>
<s>
So	O
,	O
for	O
instance	O
,	O
consider	O
this	O
JavaScript	B-Language
program	O
,	O
written	O
in	O
a	O
non-store-passing-style	O
:	O
</s>
<s>
In	O
store-passing	B-Application
style	I-Application
,	O
the	O
value	O
of	O
the	O
global	O
variable	O
(	O
or	O
variables	O
)	O
is	O
passed	O
along	O
to	O
each	O
call	O
,	O
and	O
also	O
returned	O
from	O
each	O
call	O
and	O
threaded	O
through	O
the	O
next	O
call	O
.	O
</s>
<s>
Store-passing	B-Application
style	I-Application
can	O
be	O
quite	O
painful	O
to	O
write	O
,	O
but	O
can	O
help	O
to	O
eliminate	O
race	O
conditions	O
by	O
isolating	O
state	O
within	O
function	O
calls	O
,	O
and	O
can	O
potentially	O
make	O
code	O
more	O
parallelizable	O
.	O
</s>
