<s>
High	B-Application
Level	I-Application
Assembly	I-Application
(	O
HLA	O
)	O
is	O
a	O
language	B-Application
developed	O
by	O
Randall	O
Hyde	O
that	O
allows	O
the	O
use	O
of	O
higher-level	O
language	B-Application
constructs	O
to	O
aid	O
both	O
beginners	O
and	O
advanced	O
assembly	O
developers	O
.	O
</s>
<s>
It	O
fully	O
supports	O
advanced	O
data	O
types	O
and	O
object-oriented	B-Language
programming	I-Language
.	O
</s>
<s>
It	O
uses	O
a	O
syntax	O
loosely	O
based	O
on	O
several	O
high-level	B-Language
programming	I-Language
languages	I-Language
(	O
HLLs	O
)	O
,	O
such	O
as	O
Pascal	B-Application
,	O
Ada	B-Language
,	O
Modula-2	B-Language
,	O
and	O
C++	B-Language
,	O
to	O
allow	O
the	O
creation	O
of	O
readable	O
assembly	B-Language
language	I-Language
programs	O
,	O
and	O
to	O
allow	O
HLL	O
programmers	O
to	O
learn	O
HLA	O
as	O
fast	O
as	O
possible	O
.	O
</s>
<s>
HLA	O
was	O
originally	O
conceived	O
as	O
a	O
tool	O
to	O
teach	O
assembly	B-Language
language	I-Language
programming	O
at	O
the	O
college-university	O
level	O
.	O
</s>
<s>
The	O
goal	O
is	O
to	O
leverage	O
students	O
 '	O
existing	O
programming	O
knowledge	O
when	O
learning	O
assembly	B-Language
language	I-Language
to	O
get	O
them	O
up	O
to	O
speed	O
as	O
fast	O
as	O
possible	O
.	O
</s>
<s>
Most	O
students	O
taking	O
an	O
assembly	B-Language
language	I-Language
programming	O
course	O
have	O
already	O
been	O
introduced	O
to	O
high-level	O
control	O
flow	O
structures	B-General_Concept
,	O
such	O
as	O
IF	O
,	O
WHILE	O
,	O
FOR	O
,	O
etc	O
.	O
</s>
<s>
HLA	O
allows	O
students	O
to	O
immediately	O
apply	O
that	O
programming	O
knowledge	O
to	O
assembly	B-Language
language	I-Language
coding	O
early	O
in	O
their	O
course	O
,	O
allowing	O
them	O
to	O
master	O
other	O
prerequisite	O
subjects	O
in	O
assembly	O
before	O
learning	O
how	O
to	O
code	O
low-level	O
forms	O
of	O
these	O
control	O
structures	B-General_Concept
.	O
</s>
<s>
The	O
book	O
The	O
Art	O
of	O
Assembly	B-Language
Language	I-Language
Programming	O
by	O
Randall	O
Hyde	O
uses	O
HLA	O
for	O
this	O
purpose	O
.	O
</s>
<s>
The	O
HLA	O
v2.x	O
assembler	B-Language
supports	O
the	O
same	O
low-level	O
machine	O
instructions	O
as	O
a	O
regular	O
low-level	O
assembler	B-Language
,	O
while	O
high-end	O
assemblers	B-Language
also	O
support	O
high-level-language-like	O
statements	O
,	O
such	O
as	O
IF	O
,	O
WHILE	O
,	O
and	O
so	O
on	O
,	O
and	O
fancier	O
data	O
declaration	O
directives	O
,	O
such	O
as	O
structures-records	O
,	O
unions	O
,	O
and	O
even	O
classes	O
.	O
</s>
<s>
Some	O
examples	O
of	O
high-end	O
assemblers	B-Language
are	O
HLA	O
,	O
Microsoft	B-Application
Macro	I-Application
Assembler	I-Application
(	O
MASM	B-Application
)	O
,	O
and	O
the	O
Turbo	B-Application
Assembler	I-Application
(	O
TASM	B-Application
)	O
on	O
the	O
Intel	B-Operating_System
x86	I-Operating_System
processor	O
family	O
,	O
</s>
<s>
Unlike	O
most	O
other	O
assembler	B-Language
tools	O
,	O
the	O
HLA	O
compiler	O
includes	O
a	O
Standard	O
Library	O
with	O
thousands	O
of	O
functions	O
,	O
procedures	O
,	O
and	O
macros	O
that	O
can	O
be	O
used	O
to	O
create	O
full	O
applications	O
with	O
the	O
ease	O
of	O
a	O
high-level	B-Language
language	I-Language
.	O
</s>
<s>
While	O
assembly	B-Language
language	I-Language
libraries	B-Library
are	O
not	O
new	O
,	O
a	O
language	B-Application
that	O
includes	O
a	O
large	O
standardized	O
library	O
encourages	O
programmers	O
to	O
use	O
the	O
library	O
code	O
rather	O
than	O
simply	O
writing	O
their	O
own	O
library	B-Library
functions	I-Library
.	O
</s>
<s>
HLA	O
supports	O
all	O
the	O
same	O
low-level	O
machine	O
instructions	O
as	O
other	O
x86	B-Operating_System
assemblers	B-Language
.	O
</s>
<s>
Furthermore	O
,	O
HLA	O
's	O
high-level	O
control	O
structures	B-General_Concept
are	O
based	O
on	O
the	O
ones	O
found	O
in	O
MASM	B-Application
and	O
TASM	B-Application
,	O
which	O
HLL-like	O
features	O
predated	O
the	O
arrival	O
of	O
HLA	O
by	O
several	O
years	O
.	O
</s>
<s>
In	O
HLA	O
,	O
low-level	O
assembly	B-Language
code	I-Language
can	O
be	O
written	O
as	O
easily	O
as	O
with	O
any	O
other	O
assembler	B-Language
by	O
simply	O
ignoring	O
the	O
HLL-control	O
constructs	O
.	O
</s>
<s>
In	O
contrast	O
to	O
HLLs	O
like	O
Pascal	B-Application
and	O
C( ++	O
)	O
,	O
HLA	O
does	O
n't	O
require	O
inline	O
asm	O
statements	O
.	O
</s>
<s>
In	O
practice	O
,	O
many	O
experienced	O
programmers	O
continue	O
to	O
use	O
HLL-like	O
statements	O
in	O
HLA	O
,	O
MASM	B-Application
,	O
and	O
TASM	B-Application
,	O
long	O
after	O
mastering	O
the	O
low-level	O
instruction	O
set	O
,	O
but	O
this	O
is	O
usually	O
done	O
to	O
improve	O
readability	O
.	O
</s>
<s>
It	O
is	O
also	O
possible	O
to	O
write	O
high-level	O
programs	O
using	O
HLA	O
,	O
avoiding	O
much	O
of	O
the	O
tedium	O
of	O
low-level	O
assembly	B-Language
language	I-Language
programming	O
.	O
</s>
<s>
Some	O
assembly	B-Language
language	I-Language
programmers	O
reject	O
HLA	O
out	O
of	O
hand	O
,	O
because	O
it	O
allows	O
programmers	O
to	O
do	O
this	O
.	O
</s>
<s>
However	O
,	O
supporting	O
both	O
high-level	O
and	O
low-level	O
programming	O
gives	O
any	O
language	B-Application
an	O
expanded	O
range	O
of	O
applicability	O
.	O
</s>
<s>
Two	O
HLA	O
features	O
set	O
it	O
apart	O
from	O
other	O
x86	B-Operating_System
assemblers	B-Language
:	O
its	O
powerful	O
macro	O
system	O
(	O
compile-time	O
language	B-Application
)	O
and	O
the	O
HLA	O
Standard	O
Library	O
.	O
</s>
<s>
HLA	O
's	O
compile-time	O
language	B-Application
allows	O
extending	O
the	O
language	B-Application
with	O
ease	O
,	O
even	O
creating	O
small	O
domain-specific	B-Language
languages	I-Language
to	O
help	O
easily	O
solve	O
common	O
programming	O
problems	O
.	O
</s>
<s>
Most	O
assemblers	B-Language
provide	O
some	O
sort	O
of	O
macro	O
ability	O
:	O
the	O
advantage	O
that	O
HLA	O
offers	O
over	O
other	O
assemblers	B-Language
is	O
that	O
it	O
can	O
process	O
macro	O
arguments	O
like	O
r:10:2	O
using	O
HLA	O
's	O
extensive	O
compile-time	O
string	O
functions	O
,	O
and	O
HLA	O
's	O
macro	O
facilities	O
can	O
infer	O
the	O
types	O
of	O
variables	O
and	O
use	O
that	O
information	O
to	O
direct	O
macro	O
expansion	O
.	O
</s>
<s>
HLA	O
's	O
macro	O
language	B-Application
provides	O
a	O
special	O
Context-Free	O
macro	O
facility	O
.	O
</s>
<s>
The	O
HLA	O
macro	O
system	O
is	O
actually	O
a	O
subset	O
of	O
a	O
larger	O
feature	O
known	O
as	O
the	O
HLA	O
Compile-Time	O
Language	B-Application
(	O
CTL	O
)	O
.	O
</s>
<s>
The	O
HLA	O
CTL	O
is	O
an	O
interpreted	O
language	B-Application
that	O
is	O
available	O
in	O
an	O
HLA	O
program	O
source	O
file	O
.	O
</s>
<s>
An	O
interpreter	O
executes	O
HLA	O
CTL	O
statements	O
during	O
the	O
compiling	O
of	O
an	O
HLA	O
source	O
file	O
;	O
hence	O
the	O
name	O
compile-time	O
language	B-Application
.	O
</s>
<s>
The	O
HLA	O
CTL	O
allows	O
programmers	O
to	O
create	O
CTL	O
programs	O
that	O
scan	O
and	O
parse	O
strings	O
,	O
allowing	O
those	O
programmers	O
to	O
create	O
embedded	O
domain-specific	B-Language
languages	I-Language
(	O
EDSLs	O
,	O
also	O
termed	O
mini-languages	B-Language
)	O
.	O
</s>
<s>
Perhaps	O
just	O
as	O
important	O
,	O
the	O
HLA	O
Standard	O
Library	O
allows	O
programmers	O
to	O
write	O
portable	O
applications	O
that	O
run	O
under	O
Windows	O
or	O
Linux	B-Application
with	O
nothing	O
more	O
than	O
recompiling	O
the	O
source	O
code	O
.	O
</s>
<s>
Like	O
the	B-Language
C	I-Language
standard	I-Language
library	I-Language
for	O
the	O
programming	B-Language
language	I-Language
C	I-Language
,	O
the	O
HLA	O
Standard	O
Library	O
allows	O
users	O
to	O
abstract	O
away	O
low-level	O
operating	B-General_Concept
system	I-General_Concept
(	O
OS	O
)	O
calls	O
,	O
so	O
the	O
same	O
set	O
of	O
OS	O
application	B-Application
programming	I-Application
interfaces	I-Application
(	O
APIs	B-Application
)	O
can	O
serve	O
for	O
all	O
operating	B-General_Concept
systems	I-General_Concept
that	O
HLA	O
supports	O
.	O
</s>
<s>
While	O
an	O
assembly	B-Language
language	I-Language
allows	O
making	O
any	O
needed	O
OS	O
calls	O
,	O
where	O
programs	O
use	O
the	O
HLA	O
Standard	O
Library	O
API	B-Application
set	O
,	O
writing	O
OS-portable	O
programs	O
is	O
easy	O
.	O
</s>
<s>
The	O
HLA	O
v2.x	O
language	B-Application
system	O
is	O
a	O
command-line	O
driven	O
tool	O
that	O
consists	O
of	O
several	O
components	O
,	O
including	O
a	O
shell	O
program	O
(	O
e.g.	O
,	O
hla.exe	O
under	O
Windows	O
)	O
,	O
the	O
HLA	O
language	B-Application
compiler	O
(	O
e.g.	O
,	O
hlaparse.exe	O
)	O
,	O
a	O
low-level	O
translator	O
(	O
e.g.	O
,	O
the	O
HLABE	O
,	O
or	O
HLA	O
Back	O
Engine	O
)	O
,	O
a	O
linker	B-Application
(	O
link.exe	O
under	O
Windows	O
,	O
ld	O
under	O
Linux	B-Application
)	O
,	O
and	O
other	O
tools	O
such	O
as	O
a	O
resource	O
compiler	O
for	O
Windows	O
.	O
</s>
<s>
Versions	O
before	O
2.0	O
relied	O
on	O
an	O
external	O
assembler	B-Language
back	O
end	O
;	O
versions	O
2.x	O
and	O
later	O
of	O
HLA	O
use	O
the	O
built-in	O
HLABE	O
as	O
the	O
back-end	O
object	O
code	O
formatter	O
.	O
</s>
<s>
It	O
accepts	O
as	O
input	O
.hla	O
files	O
(	O
HLA	O
source	O
files	O
)	O
,	O
.asm	O
files	O
(	O
source	O
files	O
for	O
MASM	B-Application
,	O
TASM	B-Application
,	O
FASM	B-Application
,	O
NASM	B-Application
,	O
or	O
Gas	O
assemblers	B-Language
)	O
,	O
.obj	O
files	O
for	O
input	O
to	O
the	O
linker	B-Application
,	O
and	O
.rc	O
files	O
(	O
for	O
use	O
by	O
a	O
resource	O
compiler	O
)	O
.	O
</s>
<s>
Originally	O
,	O
the	O
HLA	O
v1.x	O
tool	O
compiled	O
its	O
source	O
code	O
into	O
an	O
intermediate	O
source	O
file	O
that	O
a	O
back-end	O
assembler	B-Language
such	O
as	O
MASM	B-Application
,	O
TASM	B-Application
,	O
flat	B-Application
assembler	I-Application
(	O
FASM	B-Application
)	O
,	O
Netwide	B-Application
Assembler	I-Application
(	O
NASM	B-Application
)	O
,	O
or	O
GNU	B-Application
Assembler	I-Application
(	O
Gas	O
)	O
would	O
translate	O
into	O
the	O
low-level	O
object	O
code	O
file	O
.	O
</s>
<s>
However	O
,	O
via	O
various	O
command-line	O
parameters	O
,	O
HLA	O
v2.x	O
still	O
has	O
the	O
ability	O
to	O
translate	O
an	O
HLA	O
source	O
file	O
into	O
a	O
source	O
file	O
that	O
is	O
compatible	O
with	O
one	O
of	O
these	O
other	O
assemblers	B-Language
.	O
</s>
<s>
The	O
HLA	O
Back	O
Engine	O
(	O
HLABE	O
)	O
is	O
a	O
compiler	O
back	O
end	O
that	O
translates	O
an	O
internal	O
intermediate	O
language	B-Application
into	O
low-level	O
Portable	O
Executable	O
(	O
PE	O
)	O
,	O
Common	O
Object	O
File	O
Format	O
(	O
COFF	O
)	O
,	O
Executable	O
and	O
Linkable	O
Format	O
(	O
ELF	O
)	O
,	O
or	O
Mach-O	B-Operating_System
object	O
code	O
.	O
</s>
<s>
An	O
HLABE	O
program	O
mostly	O
consists	O
of	O
data	O
(	O
byte	O
)	O
emission	O
statements	O
,	O
32-bit	O
relocatable	O
address	O
statements	O
,	O
x86	B-Operating_System
control-transfer	O
instructions	O
,	O
and	O
various	O
directives	O
.	O
</s>
<s>
It	O
is	O
public	O
domain	O
and	O
open	O
source	O
(	O
hosted	O
on	O
SourceForge.net	B-Application
)	O
.	O
</s>
