AdvPL StringBuilder

This is an implementation of string concatenation for AdvPL based on virtual pointers and on an internal research.

Basically, in AdvPL, every string is immutable. When you do +, you have a O(n ^ 2) complexity, which is very expensive. Our implementation reduces it to O(1), preallocating and reading directly from the memory, without any dependency on +. In our tests, we've got to run 240 times faster than in the classic model. Its use is recommended only for large string concatenation operation. + is faster for small strings.

Installation

Just copy and compile the file StringBuilder.prw under ./src.

Interface

Class StringBuilder
  Method New( cInit ) Constructor
  Method Append( cBuffer )
  Method Build()
  Method Read()
  Method Dispose()
EndClass

Example

Function TestStr
  Local nI
  Local oBuilder := StringBuilder():New( 'optional initializer' )
  oBuilder:Append( '...' )
  
  For nI := 1 To 100000
    oBuilder:Append( AllTrim( Str( nI ) ) )
  Next nI
  
  ConOut( oBuilder:Read() ) // "optional initializer... 123456789101112" and so on...
  oBuilder:Dispose() // Clear garbage from memory. Manual GC

Maintainers

This project is maintained and developed by NG Informática ─ TOTVS Software Partner