<s>
SAC	O
(	O
Single	O
Assignment	O
C	B-Language
)	O
is	O
a	O
strict	O
purely	B-Application
functional	I-Application
programming	I-Application
language	O
whose	O
design	O
is	O
focused	O
on	O
the	O
needs	O
of	O
numerical	O
applications	O
.	O
</s>
<s>
Emphasis	O
is	O
laid	O
on	O
efficient	O
support	O
for	O
array	B-Algorithm
processing	I-Algorithm
via	O
data	B-Operating_System
parallelism	I-Operating_System
.	O
</s>
<s>
On	O
the	O
one	O
hand	O
,	O
efficiency	O
in	O
program	O
development	O
is	O
to	O
be	O
improved	O
by	O
the	O
opportunity	O
to	O
specify	O
array	B-Application
operations	O
on	O
a	O
high	O
level	O
of	O
abstraction	B-Application
.	O
</s>
<s>
the	O
runtime	O
performance	O
of	O
programs	O
,	O
in	O
time	O
and	O
memory	O
consumption	O
,	O
is	O
still	O
to	O
be	O
achieved	O
by	O
sophisticated	O
compilation	B-Language
schemes	O
.	O
</s>
<s>
To	O
facilitate	O
compiling	B-Language
to	O
efficiently	O
executable	O
code	O
,	O
certain	O
functional	B-Language
language	I-Language
features	O
which	O
are	O
not	O
considered	O
essential	O
for	O
numerical	O
applications	O
,	O
e.g.	O
</s>
<s>
higher-order	O
functions	O
,	O
polymorphism	B-Application
,	O
or	O
lazy	O
evaluation	O
,	O
are	O
not	O
(	O
yet	O
)	O
supported	O
by	O
SAC	O
.	O
</s>
<s>
These	O
may	O
be	O
found	O
in	O
general-purpose	O
functional	B-Language
languages	I-Language
,	O
e.g.	O
</s>
<s>
Haskell	B-Language
,	O
Clean	B-Operating_System
,	O
Miranda	B-Language
,	O
or	O
ML	B-Language
.	O
</s>
<s>
To	O
overcome	O
the	O
acceptance	O
problems	O
encountered	O
by	O
other	O
functional	B-Language
or	O
array	B-Application
based	O
languages	O
intended	O
for	O
numerical	O
/	O
array	B-Application
intensive	O
applications	O
,	O
e.g.	O
</s>
<s>
SISAL	B-Language
,	O
NESL	B-Language
,	O
Nial	B-Language
,	O
APL	B-Language
,	O
J	B-Language
,	O
or	O
K	B-Application
,	O
particular	O
regard	O
is	O
paid	O
to	O
ease	O
the	O
transition	O
from	O
a	O
C	B-Language
/	O
Fortran	B-Application
like	O
programming	O
environment	O
to	O
SAC	O
.	O
</s>
<s>
provide	O
a	O
purely	B-Application
functional	I-Application
language	O
with	O
a	O
syntax	O
very	O
similar	O
to	O
that	O
of	O
C	B-Language
in	O
order	O
to	O
ease	O
,	O
for	O
a	O
large	O
community	O
of	O
programmers	O
,	O
the	O
transition	O
from	O
an	O
imperative	O
to	O
a	O
functional	B-Language
programming	I-Language
style	O
;	O
</s>
<s>
allow	O
the	O
specification	O
of	O
shape	O
-	O
and	O
dimension-invariant	O
array	B-Application
operations	O
;	O
</s>
<s>
provide	O
high-level	O
array	B-Application
operations	O
that	O
liberate	O
programming	O
from	O
tedious	O
and	O
error-prone	O
specifications	O
of	O
starts	O
,	O
stops	O
and	O
strides	O
for	O
array	B-Application
traversals	O
thereby	O
improving	O
code	O
reusability	O
and	O
programming	O
productivity	O
,	O
in	O
general	O
.	O
</s>
<s>
incorporate	O
a	O
module	O
system	O
that	O
allows	O
for	O
separate	O
compilation	B-Language
,	O
separate	O
name	O
spaces	O
,	O
and	O
abstract	O
data	O
types	O
,	O
and	O
,	O
additionally	O
,	O
provides	O
an	O
interface	O
to	O
foreign	O
languages	O
in	O
order	O
to	O
enable	O
reuse	O
of	O
existing	O
code	O
;	O
</s>
<s>
provide	O
means	O
for	O
a	O
smooth	O
integration	O
of	O
states	O
and	O
state	O
modifications	O
into	O
the	O
functional	B-Language
paradigm	I-Language
based	O
on	O
uniqueness	O
types	O
;	O
</s>
<s>
use	O
the	O
module	O
system	O
,	O
the	O
foreign	O
language	O
interface	O
,	O
and	O
the	O
integration	O
of	O
states	O
in	O
order	O
to	O
create	O
a	O
standard	O
library	O
which	O
provides	O
a	O
functionality	O
similar	O
to	O
that	O
of	O
the	O
standard	O
C	B-Language
libraries	O
,	O
e.g.	O
</s>
<s>
facilitate	O
the	O
compilation	B-Language
to	O
host	O
machine	O
code	O
which	O
can	O
be	O
efficiently	O
executed	O
both	O
in	O
terms	O
of	O
time	O
and	O
space	O
demand	O
;	O
</s>
<s>
facilitate	O
the	O
compilation	B-Language
for	O
non-sequential	O
program	O
execution	O
in	O
multiprocessor	B-Operating_System
environments	O
.	O
</s>
