Is there such a thing as a batch code optimizer? - batch-file

Question

So you know , when people write code they do it neat, best look and most understandable. but Is there an optimizer for batch? Could someone make one?
example-
it takes existing variables and replaces them with the shortest possible variants
set whatever=whatever
echo question
set /p answer=:
if %answer%=%whatever% whatever
and turns it into
set a=whatever
echo question
set /p b=:
if %b%=%a% whatever
so it basically shortens the variables , flags (or tags or whatever like :top) and does other things I cannot thing of to basically optimize everything.

Answer 1

There are certain constructs in Batch programs that slow down the execution. The sole construct that have a major impact for this point is assemble a loop via a GOTO instead of any type of FOR command. If a large program with many GOTO's is rewritten with FOR commands, an important time saving is expected. Another aspect that affect this point is the number of commands/lines a program have, that is, a program that get the same result than another one with less lines, will run faster. The way to achieve the same things with less commands is making good use of Batch file capabilities.
For example, this code:
set /A b=a+8
set /A c=b*2
set /A d=c+e
... run slower than this one:
set /A b=a+8, c=b*2, d=c+e
This code:
command-that-return-errorlevel
if %errorlevel% equ 1 goto label-1
if %errorlevel% equ 2 goto label-2
if %errorlevel% equ 3 goto label-3
... run slower than this one:
command-that-return-errorlevel
for %%e in (1 2 3) do if %errorlevel% equ %%e goto label-%%e
... and previous one run slower than this one:
command-that-return-errorlevel
goto label-%errorlevel%
Shorten the variable names have a very little impact in the execution speed.
This way, the best option is to write Batch files using these techniques from the very beginning. There is no easy way to develop a program that read a Batch file and perform the previous changes, that is, replace GOTO's with FOR and "compress" several lines in less ones.

Answer 2

The program below is just for fun!
#echo off
setlocal EnableDelayedExpansion
rem Get a list of current variable names
(for /F "delims==" %%v in ('set') do (
echo %%v
)) > varnames.txt
rem Call the Batch file, so it creates its variables
call "%~1"
rem Create an array with new variable names
set "_numVars="
set "_nextVar="
< varnames.txt (for /F "delims==" %%v in ('set') do (
if not defined _nextVar set /P _nextVar=
if "%%v" neq "!_nextVar!" (
set /A _numVars+=1
set "var[!_numVars!]=%%v"
) else (
set "_nextVar="
)
))
del varnames.txt
rem Rename the variables in a new file
setlocal DisableDelayedExpansion
(for /F "delims=" %%a in ('findstr /N "^" "%~1"') do (
set "line=%%a"
setlocal EnableDelayedExpansion
set "line=!line:*:=!"
if defined line (
for /L %%i in (1,1,%_numVars%) do (
for /F "delims=" %%v in ("!var[%%i]!") do set "line=!line:%%v=v%%i!"
)
)
echo(!line!
endlocal
)) > "%~1.new"
This program get all variables from the Batch file given in the parameter and renames they as "v#" with a sequential number. To use this program you must remove any setlocal command from the Batch file before pass it to this program. Of course, this detail may cause several pitfalls: although the called program have Delayed Expansion already Enabled, there is no way to activate any Disable/Enable delayed expansion that the Batch file may require in order to correctly run. Besides, the program changes all strings in the Batch file that are equal to any variable name, but even if this point could be fixed (and this is a big IF, because it requires to emulate the cmd.exe Batch file parser!) this program would still be useless: as I said in my other answer, renaming the variables in a Batch file have a very little effect on its performance. I just wrote it for fun!