wht

[Bjarte Aagnes]

. generate wanted = ustrregexra(have,"(?<=.)(.)",",$1")

[Bjarte Aagnes]

 
 . generate wanted = ustrregexra(have,"(?<=.)(.)",",$1")

[Bjarte Aagnes]

clear all

* Example generated by -dataex-. To install: ssc install dataex
clear
input str2 id str6 have
"1"  ""      
"2"  ""      
"3"  "6"    
"4"  "2"    
"5"  "125"  
"6"  ""      
"7"  "123456"
"8"  "136"  
"9"  "45"    
"10" ""      
end

expand `= 10^6 '

forvalues i = 1/10 {

    keep id have
    
    timer on 11
    generate wanted_rx11 = ustrregexra(have, "(.)(?=.)", "$1,")
    timer off 11

    timer on 12
    generate wanted_rx12 = ustrregexra(have, "(?<=.)(.)", ",$1")
    timer off 12
    
    timer on 21    
    generate wanted_rx21 = ustrregexra(have, "(.)(?=.)","$1,") if !mi(have)
    timer off 21

    timer on 22
    generate wanted_rx22 = ustrregexra(have, "(?<=.)(.)", ",$1") if !mi(have)
    timer off 22
    
    timer on 99
    
    gen wanted_99 =  subinstr(trim( substr(have,1,1) + " " ///
        + substr(have,2,1) + " " /// 
        + substr(have,3,1) + " " /// 
        + substr(have,4,1) + " " /// 
        + substr(have,5,1) + " " /// 
        + substr(have,6,1) + " ")," ",",",.)

    timer off 99     
}

assert wanted_rx21 == wanted_rx11          
assert wanted_rx22 == wanted_rx11
assert wanted_99   == wanted_rx11
  
timer list