<s>
The	O
Syntax/Semantic	O
Language	O
(	O
S/SL	B-Application
)	O
is	O
an	O
executable	O
high	B-Language
level	I-Language
specification	B-Application
language	I-Application
for	O
recursive	B-Application
descent	I-Application
parsers	I-Application
,	O
semantic	O
analyzers	O
and	O
code	B-Application
generators	I-Application
developed	O
by	O
James	O
Cordy	O
,	O
Ric	O
Holt	O
and	O
David	O
Wortman	O
at	O
the	O
University	O
of	O
Toronto	O
in	O
1980	O
.	O
</s>
<s>
S/SL	B-Application
is	O
a	O
small	O
programming	O
language	O
that	O
supports	O
cheap	O
recursion	O
and	O
defines	O
input	O
,	O
output	O
,	O
and	O
error	O
token	O
names	O
(	O
values	O
)	O
,	O
semantic	O
mechanisms	O
(	O
class	O
interfaces	O
whose	O
methods	O
are	O
really	O
escapes	O
to	O
routines	O
in	O
a	O
host	O
programming	O
language	O
but	O
allow	O
good	O
abstraction	O
in	O
the	O
pseudocode	B-Language
)	O
and	O
a	O
pseudocode	B-Language
program	O
that	O
defines	O
the	O
syntax	B-Application
of	O
the	O
input	O
language	O
by	O
the	O
token	O
stream	O
the	O
program	O
accepts	O
.	O
</s>
<s>
The	O
S/SL	B-Application
processor	O
compiles	B-Language
this	O
pseudocode	B-Language
into	O
a	O
table	O
(	O
byte-codes	O
)	O
that	O
is	O
interpreted	O
by	O
the	O
S/SL	B-Application
table-walker	O
(	O
interpreter	B-Application
)	O
.	O
</s>
<s>
The	O
pseudocode	B-Language
language	O
processes	O
the	O
input	O
language	O
in	O
LL(1 )	O
recursive	B-Application
descent	I-Application
style	O
but	O
extensions	O
allow	O
it	O
to	O
process	O
any	O
LR(k )	O
language	O
relatively	O
easily	O
.	O
</s>
<s>
S/SL	B-Application
is	O
designed	O
to	O
provide	O
excellent	O
syntax	B-Application
error	O
recovery	O
and	O
repair	O
.	O
</s>
<s>
It	O
is	O
more	O
powerful	O
and	O
transparent	O
than	O
Yacc	B-Application
but	O
can	O
be	O
slower	O
.	O
</s>
<s>
S/SL	B-Application
'	O
s	O
"	O
semantic	O
mechanisms	O
"	O
extend	O
its	O
capabilities	O
to	O
all	O
phases	O
of	O
compiling	B-Language
,	O
and	O
it	O
has	O
been	O
used	O
to	O
implement	O
all	O
phases	O
of	O
compilation	B-Language
,	O
including	O
scanners	B-Application
,	O
parsers	B-Language
,	O
semantic	O
analyzers	O
,	O
code	B-Application
generators	I-Application
and	O
virtual	B-Architecture
machine	I-Architecture
interpreters	B-Application
in	O
multi-pass	O
language	O
processors	O
.	O
</s>
<s>
S/SL	B-Application
has	O
been	O
used	O
to	O
implement	O
production	O
commercial	O
compilers	B-Language
for	O
languages	O
such	O
as	O
PL/I	B-Language
,	O
Euclid	B-Language
,	O
Turing	B-Language
,	O
Ada	B-Language
,	O
and	O
COBOL	B-Application
,	O
as	O
well	O
as	O
interpreters	B-Application
,	O
command	O
processors	O
,	O
and	O
domain	O
specific	O
languages	O
of	O
many	O
kinds	O
.	O
</s>
<s>
It	O
is	O
the	O
primary	O
technology	O
used	O
in	O
IBM	O
's	O
ILE/400	O
COBOL	B-Application
compiler	B-Language
,	O
and	O
the	O
ZMailer	B-Application
mail	B-Protocol
transfer	I-Protocol
agent	I-Protocol
uses	O
S/SL	B-Application
for	O
defining	O
both	O
its	O
mail	O
router	O
processing	O
language	O
and	O
its	O
RFC	O
822	O
email	O
address	O
validation	O
.	O
</s>
