Talk:Rosetta Code/(Strictly) equal in Rexx
Rexx has two comparison operators (for testing equality)
strictly equal a==b tests the values byte for byte, so '1'==' 01e0 ' -> 0 (false)
equal a=b tests the values more generously
it strips leading and trailing blanks and, if both values are numbers compares them arithmetically (observing the Numeric Digits setting)
so '1'==' 01e0 ' -> 1 (true)
I performed a little performance test on TSO.
<lang rexx> /* REXX ***************************************************************
- Compare the performance of equal vs. strictly equal
- 05.07.2012 Walter Pachl
- /
Parse Version v Say 'eqtest on Rexx Version' v Say ' Hits Misses test = Test == == improvement' Call random 1,10,12345 /* set seed */ Do i=1 To 100000
x.i=random() End
Do rep=1 To 5
cnt.=0
Call time 'R'
Do i=1 To 100000
If x.i=999 Then cnt.1=cnt.1+1
Else cnt.0=cnt.0+1
End
cnt.=0
te=time('R')
Do i=1 To 100000
If x.i==999 Then cnt.1=cnt.1+1
Else cnt.0=cnt.0+1
End
tse=time('E')
Say right(cnt.0,5) right(cnt.1,5),
format(te,2,8) format(tse,2,8) format((100*(te-tse)/te),3,8)'%'
End
</lang>
The results: Interpreter: eqtest on Rexx Version REXX370 3.48 01 May 1992 Hits Misses test = Test == == improvement 99894 106 0.15227900 0.14603100 4.10299516% 99894 106 0.14801500 0.14583200 1.47485052% 99894 106 0.15465700 0.15261200 1.32228092% 99894 106 0.15660000 0.14936200 4.62196679% 99894 106 0.15060800 0.17170400 -14.00722410% Compiled Rexx: eqtest on Rexx Version REXXC370 3.48 23 Dec 1999 Hits Misses test = Test == == improvement 99894 106 0.01011300 0.01730900 -71.15593790% 99894 106 0.00983700 0.01328100 -35.01067400% 99894 106 0.00973800 0.01293300 -32.80961180% 99894 106 0.00984500 0.01306300 -32.68664300% 99894 106 0.01005300 0.01423700 -41.61941710% As I was part of the Compiler Development Team in the former IBM Lab Vienna I am rather proud of my friends' achievement! You are invited to test this on your platform with your Rexx!
--Walterpachl 07:28, 5 July 2012 (UTC)