<s>
Syntax-directed	B-Application
translation	I-Application
refers	O
to	O
a	O
method	O
of	O
compiler	B-Language
implementation	O
where	O
the	O
source	O
language	O
translation	O
is	O
completely	O
driven	O
by	O
the	O
parser	B-Language
.	O
</s>
<s>
A	O
common	O
method	O
of	O
syntax-directed	B-Application
translation	I-Application
is	O
translating	O
a	O
string	O
into	O
a	O
sequence	O
of	O
actions	O
by	O
attaching	O
one	O
such	O
action	O
to	O
each	O
rule	O
of	O
a	O
grammar	O
.	O
</s>
<s>
SDT	O
provides	O
a	O
simple	O
way	O
to	O
attach	O
semantics	B-Application
to	O
any	O
such	O
syntax	B-Application
.	O
</s>
<s>
Syntax-directed	B-Application
translation	I-Application
fundamentally	O
works	O
by	O
adding	O
actions	O
to	O
the	O
productions	O
in	O
a	O
context-free	O
grammar	O
,	O
resulting	O
in	O
a	O
Syntax-Directed	B-Application
Definition	I-Application
(	O
SDD	O
)	O
.	O
</s>
<s>
A	O
grammar	O
specification	O
embedded	O
with	O
actions	O
to	O
be	O
performed	O
is	O
called	O
a	O
syntax-directed	B-Application
translation	I-Application
scheme	I-Application
(	O
sometimes	O
simply	O
called	O
a	O
'	O
translation	B-Application
scheme	I-Application
 '	O
.	O
)	O
</s>
<s>
Early	O
metacompilers	B-Language
use	O
the	O
terms	O
syntax-driven	O
and	O
syntax-directed	B-Application
translation	I-Application
in	O
their	O
descriptions	O
.	O
</s>
<s>
They	O
have	O
metaprogramming	B-Application
language	O
features	O
for	O
outputting	O
code	O
.	O
</s>
<s>
See	O
metacompiler	B-Language
,	O
META	B-Application
II	I-Application
,	O
and	O
TREE-META	B-Application
.	O
</s>
