Split String Algorithm for FreeBasic

Split String Algorithm for FreeBasic

  September 09, 2022    Nikos Siatras

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I often use string expressions to pass data between web services, microcontrollers and desktop Applications and the Split algorithm is something I often use to parse them. 

Unfortunately, this algorithm is missing from the FreeBasic programming language, so I decided to publish my implementation of the Split string algorithm.

Hope you find it useful !

/'
    Split Text Algorithm v2.1 for FreeBasic 

    Author: Nikos Siatras
    https://github.com/nsiatras
'/

' Splits the textToSplit string into multiple Strings, given the delimiter 
' that separates them and adds them to the result array
Sub Split(byref stringToSplit as const String, byref delimeter as const String, result() as String)
	
    Dim lengthOfDelimeter as Integer = len(delimeter)
    Dim indexOfDelimeter as Integer = 1
    Dim delimeterCount as Integer = 0
    Dim offset as Integer
    Dim lastDelimeterIndex as Integer
    
    ' Find how many times the delimeter exists in the stringToSplit
    Do
	indexOfDelimeter = InStr(indexOfDelimeter, stringToSplit, delimeter)
	if indexOfDelimeter >0 then
	    delimeterCount += 1
	    indexOfDelimeter = indexOfDelimeter + lengthOfDelimeter
	else
	    Exit Do ' Exit Do Loop
	endif
    Loop
    
    ' The delimeter wasn't found in the string
    if delimeterCount = 0 then
	ReDim result(0)
	result(0) = stringToSplit
	return
    endif
    
    ' Resize the result array according to delimeter size
    ReDim result(delimeterCount)

    ' Serial search inside the stringToSplit in order to find the parts 
    ' separated by the delimeter and push them to the result() array
    delimeterCount = 0
    offset = 1
    indexOfDelimeter = 1 
    Do
	indexOfDelimeter = InStr(offset, stringToSplit, delimeter)
	if indexOfDelimeter > 0 then
		result(delimeterCount) = Mid(stringToSplit, offset, indexOfDelimeter - offset)
	else
	    if lastDelimeterIndex < len (stringToSplit) then
                result(delimeterCount) = Mid(stringToSplit, lastDelimeterIndex + lengthOfDelimeter)
	    endif
		
            return 'Exit the Do Loop and return!
	endif
	lastDelimeterIndex = indexOfDelimeter
        offset = indexOfDelimeter + lengthOfDelimeter
	delimeterCount += 1
    Loop
    
End Sub

'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' Test Code
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
Dim fStringToSplit as String
Dim fSplitParts () as String, tmp as String
Dim i as Integer

fStringToSplit = ",Welcome,to,Free,Basic,!"
Split(fStringToSplit,",",fSplitParts())
     
' Print the fSplitParts
for i = 0 to ubound(fSplitParts)
    print "Part #" & i & " " & fSplitParts(i)
next

print ""

fStringToSplit = "Now<>you<>know<>how<>to<>split<>strings<>!"
Split(fStringToSplit,"<>",fSplitParts())
     
' Print the fSplitParts
for i = 0 to ubound(fSplitParts)
    print "Part #" & i & " " & fSplitParts(i)
next