<s>
In	O
computer	B-General_Concept
science	I-General_Concept
,	O
a	O
chart	B-Application
parser	I-Application
is	O
a	O
type	O
of	O
parser	B-Language
suitable	O
for	O
ambiguous	O
grammars	O
(	O
including	O
grammars	O
of	O
natural	O
languages	O
)	O
.	O
</s>
<s>
It	O
uses	O
the	O
dynamic	B-Algorithm
programming	I-Algorithm
approach	O
—	O
partial	O
hypothesized	O
results	O
are	O
stored	O
in	O
a	O
structure	O
called	O
a	O
chart	O
and	O
can	O
be	O
re-used	O
.	O
</s>
<s>
This	O
eliminates	O
backtracking	B-Algorithm
and	O
prevents	O
a	O
combinatorial	O
explosion	O
.	O
</s>
<s>
Chart	B-Application
parsing	I-Application
is	O
generally	O
credited	O
to	O
Martin	O
Kay	O
.	O
</s>
<s>
A	O
common	O
approach	O
is	O
to	O
use	O
a	O
variant	O
of	O
the	O
Viterbi	B-Algorithm
algorithm	I-Algorithm
.	O
</s>
<s>
The	O
Earley	B-Algorithm
parser	I-Algorithm
is	O
a	O
type	O
of	O
chart	B-Application
parser	I-Application
mainly	O
used	O
for	O
parsing	B-Language
in	O
computational	O
linguistics	O
,	O
named	O
for	O
its	O
inventor	O
.	O
</s>
<s>
Another	O
chart	B-Application
parsing	I-Application
algorithm	O
is	O
the	O
Cocke-Younger-Kasami	B-Application
(	O
CYK	B-Application
)	O
algorithm	O
.	O
</s>
<s>
Chart	B-Application
parsers	I-Application
can	O
also	O
be	O
used	O
for	O
parsing	B-Language
computer	O
languages	O
.	O
</s>
<s>
Earley	B-Algorithm
parsers	I-Algorithm
in	O
particular	O
have	O
been	O
used	O
in	O
compiler-compilers	B-Language
where	O
their	O
ability	O
to	O
parse	B-Language
using	O
arbitrary	O
Context-free	O
grammars	O
eases	O
the	O
task	O
of	O
writing	O
the	O
grammar	O
for	O
a	O
particular	O
language	O
.	O
</s>
<s>
In	O
bidirectional	O
chart	B-Application
parsing	I-Application
,	O
edges	O
of	O
the	O
chart	O
are	O
marked	O
with	O
a	O
direction	O
,	O
either	O
forwards	O
or	O
backwards	O
,	O
and	O
rules	O
are	O
enforced	O
on	O
the	O
direction	O
in	O
which	O
edges	O
must	O
point	O
in	O
order	O
to	O
be	O
combined	O
into	O
further	O
edges	O
.	O
</s>
<s>
In	O
incremental	O
chart	B-Application
parsing	I-Application
,	O
the	O
chart	O
is	O
constructed	O
incrementally	O
as	O
the	O
text	O
is	O
edited	O
by	O
the	O
user	O
,	O
with	O
each	O
change	O
to	O
the	O
text	O
resulting	O
in	O
the	O
minimal	O
possible	O
corresponding	O
change	O
to	O
the	O
chart	O
.	O
</s>
<s>
Chart	B-Application
parsers	I-Application
are	O
distinguished	O
between	O
top-down	B-Application
and	O
bottom-up	B-Application
,	O
as	O
well	O
as	O
active	O
and	O
passive	O
.	O
</s>
