<s>
Tree	O
Description	O
Language	O
(	O
TreeDL	B-Language
)	O
is	O
a	O
computer	B-Language
language	I-Language
for	O
description	O
of	O
strictly-typed	O
tree	B-Application
data	I-Application
structures	I-Application
and	O
operations	O
on	O
them	O
.	O
</s>
<s>
The	O
main	O
use	O
of	O
TreeDL	B-Language
is	O
in	O
the	O
development	O
of	O
language-oriented	O
tools	O
(	O
compilers	B-Language
,	O
translators	O
,	O
etc	O
.	O
)	O
</s>
<s>
for	O
the	O
description	O
of	O
a	O
structure	O
of	O
abstract	B-Data_Structure
syntax	I-Data_Structure
trees	I-Data_Structure
.	O
</s>
<s>
a	O
documentation	O
of	O
interface	O
between	O
parser	B-Language
and	O
other	O
subsystems	O
;	O
</s>
<s>
a	O
source	O
for	O
generation	O
of	O
various	O
support	O
code	O
:	O
visitors	O
,	O
walkers	O
,	O
factories	B-Application
,	O
etc	O
.	O
</s>
<s>
TreeDL	B-Language
can	O
be	O
used	O
with	O
any	O
parser	B-Language
generator	I-Language
that	O
allows	O
custom	O
actions	O
during	O
parsing	O
(	O
for	O
example	O
,	O
ANTLR	B-Application
,	O
JavaCC	B-Language
)	O
.	O
</s>
<s>
Attributes	O
are	O
used	O
to	O
store	O
literals	O
during	O
tree	O
construction	O
and	O
additional	O
information	O
gathered	O
during	O
tree	O
analysis	O
(	O
for	O
example	O
,	O
links	O
between	O
reference	O
and	O
definition	O
,	O
to	O
represent	O
higher-order	B-Application
abstract	I-Application
syntax	I-Application
)	O
.	O
</s>
