<s>
A	O
strict	B-Application
programming	I-Application
language	I-Application
is	O
a	O
programming	O
language	O
which	O
employs	O
a	O
strict	O
programming	O
paradigm	O
,	O
allowing	O
only	O
strict	O
functions	O
(	O
functions	O
whose	O
parameters	O
must	O
be	O
evaluated	O
completely	O
before	O
they	O
may	O
be	O
called	O
)	O
to	O
be	O
defined	O
by	O
the	O
user	O
.	O
</s>
<s>
A	O
non-strict	B-Application
programming	I-Application
language	I-Application
allows	O
the	O
user	O
to	O
define	O
non-strict	O
functions	O
,	O
and	O
hence	O
may	O
allow	O
lazy	O
evaluation	O
.	O
</s>
<s>
Examples	O
include	O
C#	B-Application
,	O
Java	B-Language
,	O
Perl	B-Language
(	O
all	O
versions	O
,	O
i.e.	O
</s>
<s>
through	O
version5	O
and	O
version	O
7	O
)	O
,	O
Python	B-Language
,	O
Ruby	B-Language
,	O
Common	B-Language
Lisp	I-Language
,	O
and	O
ML	B-Language
.	O
</s>
<s>
Some	O
strict	B-Application
programming	I-Application
languages	I-Application
include	O
features	O
that	O
mimic	O
laziness	O
.	O
</s>
<s>
Raku	O
,	O
formerly	O
known	O
as	O
Perl	B-Language
6	O
,	O
has	O
lazy	O
lists	O
.	O
</s>
<s>
Python	B-Language
has	O
generator	O
functions	O
.	O
</s>
<s>
Julia	B-Application
provides	O
a	O
macro	O
system	O
to	O
build	O
non-strict	O
functions	O
,	O
as	O
does	O
Scheme	B-Language
.	O
</s>
<s>
Examples	O
for	O
non-strict	B-Application
languages	I-Application
are	O
Haskell	B-Language
,	O
R	O
,	O
Miranda	B-Language
,	O
and	O
Clean	B-Operating_System
.	O
</s>
<s>
In	O
most	O
non-strict	B-Application
languages	I-Application
the	O
non-strictness	O
extends	O
to	O
data	O
constructors	O
.	O
</s>
<s>
It	O
also	O
allows	O
for	O
the	O
use	O
of	O
very	O
large	O
but	O
finite	O
data	O
structures	O
such	O
as	O
the	O
complete	O
game	O
tree	O
of	O
chess	B-Application
.	O
</s>
<s>
Because	O
of	O
the	O
uncertainty	O
regarding	O
if	O
and	O
when	O
expressions	O
will	O
be	O
evaluated	O
,	O
non-strict	B-Application
languages	I-Application
generally	O
must	O
be	O
purely	O
functional	O
to	O
be	O
useful	O
.	O
</s>
<s>
All	O
hardware	O
architectures	O
in	O
common	O
use	O
are	O
optimized	O
for	O
strict	B-Application
languages	I-Application
,	O
so	O
the	O
best	O
compilers	O
for	O
non-strict	B-Application
languages	I-Application
produce	O
slower	O
code	O
than	O
the	O
best	O
compilers	O
for	O
strict	B-Application
languages	I-Application
.	O
</s>
<s>
Strict	B-Application
programming	I-Application
languages	I-Application
are	O
often	O
associated	O
with	O
eager	O
evaluation	O
,	O
and	O
non-strict	B-Application
languages	I-Application
with	O
lazy	O
evaluation	O
,	O
but	O
other	O
evaluation	B-Language
strategies	I-Language
are	O
possible	O
in	O
each	O
case	O
.	O
</s>
<s>
The	O
terms	O
"	O
eager	O
programming	O
language	O
"	O
and	O
"	O
lazy	O
programming	O
language	O
"	O
are	O
often	O
used	O
as	O
synonyms	O
for	O
"	O
strict	B-Application
programming	I-Application
language	I-Application
"	O
and	O
"	O
non-strict	B-Application
programming	I-Application
language	I-Application
"	O
respectively	O
.	O
</s>
<s>
In	O
many	O
strict	B-Application
languages	I-Application
,	O
some	O
advantages	O
of	O
non-strict	O
functions	O
can	O
be	O
obtained	O
through	O
the	O
use	O
of	O
macros	O
or	O
thunks	B-Application
.	O
</s>
