Chip: If you haven't grabbed a copy already <http://www.pluggers.nl/product/api-pack/>, API Pack has a few BLOB routines that you might find handy including API Find in Blob, API Replace in Blob.
-- Douglas von Roeder 949-336-2902 On Wed, Nov 16, 2016 at 12:44 PM, Alan Chan <[email protected]> wrote: > 1) Position use starting position > 2) Position use * if possible - huge performance difference > 3) Never change size of your source or result during process - this is the > major issue for the performance > 4) If your library are being used with large source/result often, try use > blob which would be very fast. > > Alan Chan > > > 4D iNug Technical <[email protected]> writes: > >I have a routine which parses text. > >It seemed to function well, until recently, when I had to feed it 50 > >megs of text (48.3 million characters). > >The data is Cr delimited, and each line of text is of variable length. > > > >I am using the below mentioned truncate option, so each time the > >source/original text is shorter. > > > > > >it takes a LONG time to process. > >the basic scheme is: > >- Locate desired delimiter (1 or more characters) occurrence (1 or more > >times) > >- return text between either start of text, or previous delimiter and > >final > >- optionally truncate original text removing located text. > > > >ex: > >utl_ParseString("A,B,C,D,E,F"; 3; ",") -> "C" > > > >if truncating, the original text ("A,B,C,D,E,F") would become "D,E,F" > > > >The routine uses Substring, and Position to accomplish this task. > > > >Does anyone have a "better" text parser? > > > > > >-------- > >Follows my parsing code: > > //Project Method: utl_parsestring > > // $1 - text - to be searched > > // $2 - integer - number of times to locate character > > // $3 - string (optional ) - the character to search for (default = > >Tab) > > // $4 - pointer (optional) - pointer to initial string to allow > >truncation > > // (Destructive parsing) > > > > //RETURNS - text - text found between occurence N and N-1(preceeding) > > //instance of the seperator character indicated > > //Ex: utl_ParseString("A,B,C,D,E,F"; 3; ",") -> "C" > > // utl_ParseString("A,B,C,D,E,F"; 1; ",") -> "A" > > // utl_ParseString("A,B,C,D,E,F"; 6; ",") -> "F" > > // utl_ParseString("A,B,C,D,E,F"; 0; ",") -> "" > >C_TEXT($0;$String;$1;$Return_Value) > >C_LONGINT($wanted;$2;$i;$Found) > >C_TEXT($Search;$3) > >C_POINTER($4;$Truncate) > > > >$String:=$1 //string/text to be searched > >$Wanted:=$2 //the number of times to find the character in the > >incomming string > > > >If (Count parameters=2) //if this is looking just for tabs > >$Search:=<>x_Tab > >Else //assign passed string > >$Search:=$3 > >End if > > > >If (Count parameters=4) //we want to destructively parse the incomming > >string > >$Truncate:=$4 //pointer to value to truncate > >End if > > > >If ($Wanted>0) & ($String#"") //if the number wanted is > 0 find > >instance > > > >For ($i;1;$Wanted) > >$Found:=utl_text_Position ($Search;$String) //locate next instance of > >character > > > >Case of > >: ($i<$Wanted) & ($Found>0) //if the number of char wanted is not yet > >reached > >$String:=Substring($String;$Found+1) > > > >: ($Wanted=$i) & ($Found>0) //instance found > >$Return_Value:=Substring($String;1;$Found-1) > > > >If (Count parameters=4) //truncation was asked for, remove the > >returned string (and everyhting before it) > >$Truncate->:=Substring($String;$Found+Length($Search)) //replace the > >incomming string with the truncated version (found removed) > >End if > > > >: ($Found=0) //no more instances > >$i:=$Wanted+1 //end loop > >$Return_Value:=$String > > > >If (Count parameters=4) > >$Truncate->:="" //replace the incomming string with empty string > >End if > >End case > >End for > >Else //else # wanted <= zero return empty string > >$Return_Value:="" > >End if > >$0:=$Return_Value > > // > >********************************************************************** > >4D Internet Users Group (4D iNUG) > >FAQ: http://lists.4d.com/faqnug.html > >Archive: http://lists.4d.com/archives.html > >Options: http://lists.4d.com/mailman/options/4d_tech > >Unsub: mailto:[email protected] > >********************************************************************** > > ********************************************************************** > 4D Internet Users Group (4D iNUG) > FAQ: http://lists.4d.com/faqnug.html > Archive: http://lists.4d.com/archives.html > Options: http://lists.4d.com/mailman/options/4d_tech > Unsub: mailto:[email protected] > ********************************************************************** > ********************************************************************** 4D Internet Users Group (4D iNUG) FAQ: http://lists.4d.com/faqnug.html Archive: http://lists.4d.com/archives.html Options: http://lists.4d.com/mailman/options/4d_tech Unsub: mailto:[email protected] **********************************************************************
