<s>
ML/1	B-Language
(	O
Macro	O
Language/One	O
)	O
is	O
a	O
powerful	O
general-purpose	B-Application
macro	I-Application
processor	I-Application
.	O
</s>
<s>
Typical	O
uses	O
of	O
ML/1	B-Language
include	O
:	O
</s>
<s>
ML/1	B-Language
was	O
developed	O
in	O
1966	O
by	O
Peter	O
J	O
.	O
</s>
<s>
In	O
1984	O
,	O
Robert	O
D	O
.	O
Eager	O
,	O
one	O
of	O
Peter	O
Brown	O
's	O
colleagues	O
at	O
the	O
University	O
of	O
Kent	O
,	O
rewrote	O
ML/I	B-Language
,	O
first	O
in	O
BCPL	B-Language
in	O
1981	O
,	O
and	O
later	O
in	O
C	B-Language
in	O
1984	O
,	O
which	O
increased	O
its	O
portability	O
.	O
</s>
<s>
Note	O
that	O
Peter	O
Brown	O
's	O
original	O
name	O
for	O
the	O
language	O
was	O
ML/I	B-Language
,	O
where	O
(	O
as	O
in	O
IBM	O
's	O
PL/I	B-Language
)	O
the	O
last	O
character	O
is	O
the	O
Roman	O
numeral	O
"	O
I	O
"	O
,	O
not	O
the	O
Arabic	O
numeral	O
"	O
1	O
"	O
.	O
</s>
<s>
Most	O
subsequent	O
implementations	O
however	O
have	O
been	O
called	O
ML/1	B-Language
(	O
where	O
the	O
last	O
character	O
is	O
the	O
Arabic	O
numeral	O
"	O
1	O
"	O
)	O
.	O
</s>
<s>
Since	O
then	O
,	O
ML/1	B-Language
has	O
been	O
ported	O
to	O
many	O
platforms	O
and	O
operating	O
systems	O
,	O
including	O
VMS	B-Operating_System
,	O
MVS	B-Application
,	O
MS-DOS	B-Application
,	O
OS/2	B-Application
,	O
and	O
UNIX	B-Application
.	O
</s>
<s>
In	O
his	O
implementations	O
of	O
ML/1	B-Language
,	O
Bob	O
Eager	O
has	O
added	O
features	O
and	O
capabilities	O
in	O
addition	O
to	O
those	O
originally	O
specified	O
in	O
Peter	O
Brown	O
's	O
thesis	O
.	O
</s>
<s>
That	O
version	O
is	O
available	O
for	O
multiple	O
platforms	O
via	O
the	O
ML/1	B-Language
web	O
site	O
,	O
.	O
</s>
<s>
The	O
ML/1	B-Language
web	O
site	O
provides	O
further	O
information	O
about	O
ML/1	B-Language
,	O
as	O
well	O
as	O
documentation	O
(	O
including	O
a	O
tutorial	O
,	O
simple	O
introductory	O
guide	O
,	O
and	O
full	O
user	O
manual	O
)	O
.	O
</s>
<s>
Although	O
the	O
total	O
number	O
of	O
ML/1	B-Language
users	O
in	O
the	O
world	O
is	O
small	O
,	O
there	O
are	O
ML/1	B-Language
users	O
all	O
over	O
the	O
world	O
,	O
and	O
Bob	O
has	O
corresponded	O
with	O
ML/1	B-Language
users	O
in	O
the	O
United	O
States	O
,	O
Canada	O
,	O
Australia	O
,	O
New	O
Zealand	O
,	O
Germany	O
,	O
Holland	O
,	O
and	O
India	O
.	O
</s>
<s>
In	O
a	O
1976	O
paper	O
,	O
Andrew	O
S	O
.	O
Tanenbaum	O
describes	O
using	O
ML/I	B-Language
as	O
a	O
compiler-compiler	B-Language
.	O
</s>
<s>
ML/I	B-Language
accepts	O
input	O
in	O
completely	O
free	O
form	O
,	O
treating	O
data	O
as	O
a	O
stream	O
of	O
bytes	O
rather	O
than	O
a	O
series	O
of	O
lines	O
or	O
records	O
.	O
</s>
<s>
ML/I	B-Language
was	O
used	O
to	O
implement	O
several	O
items	O
of	O
portable	O
software	O
,	O
including	O
itself	O
.	O
</s>
<s>
This	O
mapping	O
was	O
done	O
using	O
ML/I	B-Language
itself	O
.	O
</s>
<s>
After	O
this	O
mapping	O
ML/I	B-Language
was	O
often	O
used	O
to	O
implement	O
SIL	O
's	O
(	O
system	O
implementation	O
languages	O
,	O
such	O
as	O
C	B-Language
)	O
for	O
the	O
new	O
generation	O
of	O
16-bit	B-Device
architecture	I-Device
minicomputers	B-Architecture
.	O
</s>
<s>
In	O
the	O
most	O
basic	O
terms	O
,	O
here	O
's	O
how	O
ML/1	B-Language
works	O
.	O
</s>
<s>
The	O
user	O
supplies	O
ML/1	B-Language
with	O
a	O
file	O
containing	O
input	O
text	O
.	O
</s>
<s>
In	O
another	O
file	O
(	O
or	O
,	O
optionally	O
,	O
in	O
the	O
same	O
file	O
)	O
the	O
user	O
supplies	O
a	O
set	O
of	O
ML/1	B-Language
macros	O
.	O
</s>
<s>
The	O
macros	O
tell	O
the	O
ML/1	B-Language
interpreter	O
what	O
insertions	O
,	O
deletions	O
,	O
expansions	O
,	O
translations	O
and	O
other	O
modifications	O
the	O
user	O
wants	O
made	O
to	O
the	O
input	O
text	O
.	O
</s>
<s>
When	O
ML/1	B-Language
is	O
run	O
on	O
the	O
input	O
text	O
,	O
ML/1	B-Language
follows	O
the	O
instructions	O
in	O
the	O
ML/1	B-Language
macros	O
,	O
changes	O
the	O
text	O
,	O
and	O
writes	O
out	O
a	O
new	O
file	O
containing	O
the	O
modified	O
text	O
.	O
</s>
<s>
There	O
are	O
several	O
ways	O
in	O
which	O
ML/1	B-Language
is	O
more	O
powerful	O
than	O
simple	O
"	O
scan	O
and	O
replace	O
"	O
utilities	O
.	O
</s>
<s>
ML/1	B-Language
does	O
not	O
process	O
text	O
on	O
a	O
character-string	O
by	O
character-string	O
basis	O
;	O
it	O
processes	O
text	O
on	O
a	O
word	O
by	O
word	O
(	O
or	O
,	O
in	O
ML/1	B-Language
'	O
s	O
terminology	O
,	O
on	O
an	O
"	O
atom	O
by	O
atom	O
"	O
)	O
basis	O
.	O
</s>
<s>
With	O
ML/1	B-Language
,	O
in	O
contrast	O
,	O
this	O
will	O
not	O
happen	O
because	O
the	O
string	O
"	O
DO	O
"	O
will	O
trigger	O
text-replacement	O
only	O
when	O
it	O
occurs	O
as	O
a	O
word	O
(	O
that	O
is	O
,	O
when	O
it	O
is	O
preceded	O
and	O
followed	O
by	O
delimiters	O
such	O
as	O
spaces	O
,	O
tabs	O
,	O
newlines	O
,	O
or	O
punctuation	O
characters	O
)	O
.	O
</s>
<s>
ML/1	B-Language
,	O
rather	O
than	O
operating	O
on	O
a	O
line-by-line	O
basis	O
,	O
recognizes	O
patterns	O
of	O
text	O
that	O
can	O
be	O
quite	O
complex	O
,	O
nested	O
,	O
with	O
multiple	O
delimiters	O
,	O
and	O
spanning	O
many	O
lines	O
.	O
</s>
<s>
ML/1	B-Language
can	O
,	O
for	O
instance	O
,	O
process	O
a	O
pattern	O
such	O
as	O
the	O
common	O
programming	O
language	O
IF	O
...	O
THEN	O
...	O
</s>
<s>
ML/1	B-Language
can	O
recognize	O
embedded	O
comments	O
and	O
literal	O
quotations	O
,	O
and	O
protect	O
them	O
from	O
alteration	O
.	O
</s>
<s>
In	O
order	O
to	O
deal	O
with	O
such	O
complicated	O
patterns	O
,	O
ML/1	B-Language
needs	O
to	O
be	O
a	O
programming	O
language	O
in	O
its	O
own	O
right	O
.	O
</s>
<s>
Like	O
other	O
programming	O
languages	O
,	O
ML/1	B-Language
supports	O
variables	O
and	O
assignment	O
statements	O
,	O
GOTOs	O
and	O
labels	O
,	O
IF	O
...	O
THEN	O
tests	O
and	O
loops	O
.	O
</s>
<s>
These	O
features	O
give	O
ML/1	B-Language
an	O
unusual	O
degree	O
of	O
power	O
and	O
flexibility	O
.	O
</s>
<s>
ML/1	B-Language
is	O
case-sensitive	O
,	O
so	O
it	O
does	O
not	O
support	O
case-insensitive	O
text	O
processing	O
.	O
</s>
