Batch "macros" with arguments
Posted: 18 May 2011 21:47
IMPORTANT UPDATE - See Macros with parameters appended for major improvements to the basic construction of a macro with arguments. But by all means, read this thread to get a basic understanding of macros along with many important macro concepts and design techniques.
All languages have time consuming overhead when calling a function. Unfortunately the time overhead for a batch function call can get quite large, especially when the batch file becomes large.
Many languages have the ability to avoid function call overhead via macros. It is common practice in "DOS" batch files to emulate a simple macro by storing commands in a variable, but typical implementations do not support arguments. DOSKEY supports true macros with arguments, but they can't be used in batch.
I've often wanted batch macros with arguments, but didn't think it was possible - until...
Ed Dyreen introduced a working emulation of macros with arguments in this thread SET /a -- Random Number!
I've been working with the basic syntax he developed, and I think it has a lot of potential, even for moderately complex algorithms. It's even possible to format the macro definitions and macro "calls" so they are relatively easy to read and understand.
I've prepared three sample macros that have identical functionality to existing functions. I also implemented timing routines as macros.
Not only are the macros faster, their performance should remain unchanged regardless of the size of the batch file.
Besides significant speed improvements over functions, the macros are very easy to use in multiple batch files. A library of macros can be defined by running a single batch file. Then any number of batch files can utilize the macros without worrying about including them in the file!
There are still some things to figure out:
- I think the macros that return numbers are good to go, but the toLower macro has issues with the FOR /F eol problem. We don't want any delimiter and the returned string could start with any character. I couldn't figure out how to use Jeb's technique of eol=<LF> in the macro.
- I'm wondering if a macro can call a macro? I haven't figured out a way to do this.
- Debugging is impacted and takes some getting used to. (I'm not there yet!)
- I imagine there are other issues yet to be discovered!
See my Batch "macros" with arguments - Major Update post on the 3rd page of this thread for significant updates to this batch project.
results:
Dave Benham
All languages have time consuming overhead when calling a function. Unfortunately the time overhead for a batch function call can get quite large, especially when the batch file becomes large.
Many languages have the ability to avoid function call overhead via macros. It is common practice in "DOS" batch files to emulate a simple macro by storing commands in a variable, but typical implementations do not support arguments. DOSKEY supports true macros with arguments, but they can't be used in batch.
I've often wanted batch macros with arguments, but didn't think it was possible - until...
Ed Dyreen introduced a working emulation of macros with arguments in this thread SET /a -- Random Number!
I've been working with the basic syntax he developed, and I think it has a lot of potential, even for moderately complex algorithms. It's even possible to format the macro definitions and macro "calls" so they are relatively easy to read and understand.
I've prepared three sample macros that have identical functionality to existing functions. I also implemented timing routines as macros.
Not only are the macros faster, their performance should remain unchanged regardless of the size of the batch file.
Besides significant speed improvements over functions, the macros are very easy to use in multiple batch files. A library of macros can be defined by running a single batch file. Then any number of batch files can utilize the macros without worrying about including them in the file!
There are still some things to figure out:
- I think the macros that return numbers are good to go, but the toLower macro has issues with the FOR /F eol problem. We don't want any delimiter and the returned string could start with any character. I couldn't figure out how to use Jeb's technique of eol=<LF> in the macro.
- I'm wondering if a macro can call a macro? I haven't figured out a way to do this.
- Debugging is impacted and takes some getting used to. (I'm not there yet!)
- I imagine there are other issues yet to be discovered!
See my Batch "macros" with arguments - Major Update post on the 3rd page of this thread for significant updates to this batch project.
Code: Select all
@echo off
setlocal
::------------------------------------------
:: DEFINE MACROS
set callMacro=for /f "tokens=1-26" %%a in
set macroNum2Hex=do^
setlocal enableDelayedExpansion^
^&(if defined hex set "hex=")^
^&set /a "dec=(%%~a)"^
^&set "map=0123456789ABCDEF"^
^&(for /l %%n in (1,1,8) do^
set /a "d=dec&15,dec>>=4"^
^&for %%d in (!d!) do set "hex=!map:~%%d,1!!hex!"^
)^
^&(for %%v in (!hex!) do endlocal^&if "%%~b" neq "" (set %%~b=%%v) else echo %%v)
set macroStrLen=do^
setlocal enableDelayedExpansion^
^&set "str=A!%%~a!"^
^&set "len=0"^
^&(for /l %%A in (12,-1,0) do^
set /a "len|=1<<%%A"^
^&for %%B in (!len!) do if "!str:~%%B,1!"=="" set /a "len&=~1<<%%A"^
)^
^&(for %%v in (!len!) do endlocal^&if "%%~b" neq "" (set %%~b=%%v) else echo %%v)
set macroToLower=do^
setlocal enableDelayedExpansion^
^&set "str=!%%~a!"^
^&(for %%A in (^
"A=a" "B=b" "C=c" "D=d" "E=e" "F=f" "G=g" "H=h" "I=i"^
"J=j" "K=k" "L=l" "M=m" "N=n" "O=o" "P=p" "Q=q" "R=r"^
"S=s" "T=t" "U=u" "V=v" "W=w" "X=x" "Y=y" "Z=z" "Ä=ä"^
"Ö=ö" "Ü=ü"^
) do set "str=!str:%%~A!")^
^&(for /f "delims=" %%v in ("!str!") do endlocal^&set "%%~a=%%~v")
set macroGetTime=do^
setlocal enableDelayedExpansion^
^&set "t=0"^
^&(for /f "tokens=1-4 delims=:." %%A in ("!time: =0!") do set /a "t=(((1%%A*60)+1%%B)*60+1%%C)*100+1%%D-36610100")^
^&(for %%v in (!t!) do endlocal^&set %%~a=%%v)
set macroDiffTime=do^
setlocal enableDelayedExpansion^
^&set /a "DD=(%%~b)-(%%~a)"^
^&(if !DD! lss 0 set /a "DD+=24*60*60*100")^
^&set /a "HH=DD/360000, DD-=HH*360000, MM=DD/6000, DD-=MM*6000, SS=DD/100, DD-=SS*100"^
^&(if "!HH:~1!"=="" set "HH=0!HH!")^
^&(if "!MM:~1!"=="" set "MM=0!MM!")^
^&(if "!SS:~1!"=="" set "SS=0!SS!")^
^&(if "!DD:~1!"=="" set "DD=0!DD!")^
^&(for %%v in (!HH!:!MM!:!SS!.!DD!) do endlocal^&if "%%~c" neq "" (set %%~c=%%v) else echo %%v)
:: END MACROS
::------------------------------------------
set "txt=I Wonder HOW long this text string is?"
::==== Test Macros =============================
echo --------------------------
echo Macro results:
set result=
%callMacro% ("56789") %macroNum2Hex%
%callMacro% ("-1 result") %macroNum2Hex%
set result
%callMacro% ("t1") %macroGetTime%
(for /l %%n in (1,1,255) do %callMacro% ("%%n result") %macroNum2Hex%)
%callMacro% ("t2") %macroGetTime%
%callMacro% ("t1 t2 timeMacroNum2Hex") %macroDiffTime%
set result
set "result=%txt%"
%callMacro% ("t1") %macroGetTime%
(for /l %%n in (1,1,255) do %callMacro% ("result") %macroToLower%)
%callMacro% ("t2") %macroGetTime%
%callMacro% ("t1 t2 timeMacroToLower") %macroDiffTime%
set result
%callMacro% ("txt") %macroStrLen%
%callMacro% ("t1") %macroGetTime%
(for /l %%n in (1,1,255) do %callMacro% ("txt result") %macroStrLen%)
%callMacro% ("t2") %macroGetTime%
%callMacro% ("t1 t2 timeMacroStrLen") %macroDiffTime%
set result
::===== Test Function Calls ====================
echo --------------------------
echo Call results:
set result=
call :num2hex 56789
call :num2hex -1 result
set result
%callMacro% ("t1") %macroGetTime%
for /l %%n in (1,1,255) do call :num2hex %%n result
%callMacro% ("t2") %macroGetTime%
%callMacro% ("t1 t2 timeNum2Hex") %macroDiffTime%
set result
set "result=%txt%"
%callMacro% ("t1") %macroGetTime%
for /l %%n in (1,1,255) do call :toLower result
%callMacro% ("t2") %macroGetTime%
%callMacro% ("t1 t2 timeToLower") %macroDiffTime%
set result
call :strLen txt
%callMacro% ("t1") %macroGetTime%
for /l %%n in (1,1,255) do call :strLen txt result
%callMacro% ("t2") %macroGetTime%
%callMacro% ("t1 t2 timeStrLen") %macroDiffTime%
set result
::==== Show timings =============================
echo -------------------------
echo:num2Hex macro time x 255 = %timeMacroNum2Hex%
echo: call time x 255 = %timeNum2Hex%
echo:
echo:toLower macro time x 255 = %timeMacroToLower%
echo: call time x 255 = %timeToLower%
echo:
echo:strLen macro time x 255 = %timeMacroStrLen%
echo: call time x 255 = %timeStrLen%
exit /b
::------------------------------------------------------
:: Begin function definitions
:num2hex NumVal [RtnVar]
setlocal enabledelayedexpansion
set /a dec=%~1 2>nul
if defined hex set hex=
set "map=0123456789ABCDEF"
for /l %%n in (1,1,8) do (
set /a "d=dec&15,dec>>=4"
for %%d in (!d!) do set "hex=!map:~%%d,1!!hex!"
)
endlocal&if "%~2" neq "" (set %~2=%hex%) else echo:%hex%
exit /b
:strLen string len -- returns the length of a string
setlocal enabledelayedexpansion
set "str=A!%~1!"
set "len=0"
for /l %%A in (12,-1,0) do (
set /a "len|=1<<%%A"
for %%B in (!len!) do if "!str:~%%B,1!"=="" set /a "len&=~1<<%%A"
)
endlocal&if "%~2" neq "" (set /a %~2=%len%) else echo:%len%
exit /b
:toLower strVar
setlocal enabledelayedexpansion
set "str=!%~1!"
for %%A in (
"A=a" "B=b" "C=c" "D=d" "E=e" "F=f" "G=g" "H=h" "I=i"
"J=j" "K=k" "L=l" "M=m" "N=n" "O=o" "P=p" "Q=q" "R=r"
"S=s" "T=t" "U=u" "V=v" "W=w" "X=x" "Y=y" "Z=z" "Ä=ä"
"Ö=ö" "Ü=ü"
) do set str=!str:%%~A!
endlocal & set %~1=%str%
exit /b
results:
Code: Select all
--------------------------
Macro results:
0000DDD5
result=FFFFFFFF
result=000000FF
result=i wonder how long this text string is?
38
result=38
--------------------------
Call results:
0000DDD5
result=FFFFFFFF
result=000000FF
result=i wonder how long this text string is?
38
result=38
-------------------------
num2Hex macro time x 255 = 00:00:00.57
call time x 255 = 00:00:02.19
toLower macro time x 255 = 00:00:00.71
call time x 255 = 00:00:02.19
strLen macro time x 255 = 00:00:00.71
call time x 255 = 00:00:02.15
Dave Benham
Below is the timing portion of the output:
I tried and failed miserably: 
It is dependent on at least one undefined variable/macro (%ERR.Set.VALID%). I also suspect you are including some other abstract concept like objects that is further confusing me. Is the trick to use delayed expansion when calling a macro from a macro? Can you provide a small working example that focuses on a macro calling a macro 
