<s>
A	O
combinator	B-Library
library	I-Library
is	O
a	O
software	B-Library
library	I-Library
which	O
implements	O
combinators	B-Application
for	O
a	O
functional	B-Language
programming	I-Language
language	I-Language
;	O
"	O
the	O
key	O
idea	O
is	O
this	O
:	O
a	O
combinator	B-Library
library	I-Library
offers	O
functions	O
(	O
the	O
combinators	B-Application
)	O
that	O
combine	O
functions	O
together	O
to	O
make	O
bigger	O
functions	O
"	O
.	O
</s>
<s>
These	O
kinds	O
of	O
libraries	O
are	O
particularly	O
useful	O
for	O
allowing	O
domain-specific	B-Language
programming	I-Language
languages	I-Language
to	O
be	O
easily	O
embedded	O
into	O
a	O
general	O
purpose	O
language	O
by	O
defining	O
a	O
few	O
primitive	O
functions	O
for	O
the	O
given	O
domain	O
and	O
turning	O
over	O
the	O
task	O
of	O
expanding	O
higher-level	O
constructs	O
to	O
the	O
general	O
language	O
.	O
</s>
<s>
An	O
example	O
would	O
be	O
the	O
monadic	O
Parsec	B-Language
parser	I-Language
for	O
Haskell	B-Language
.	O
</s>
