PPMD Compression: String to Compressed Bytes

Demonstrates how to compress a string to a compressed byte array using PPMD.

Download the Chilkat Compression ActiveX here: ChilkatCompression.zip
Unzip and register the DLL with regsvr32. (This is a pre-release)

LOCAL loCompress
LOCAL lnSuccess
LOCAL lcStrData
LOCAL i
LOCAL loCompressedBytes
LOCAL lcStrOriginal

loCompress = CreateObject('Chilkat.Compression')

*  Any string argument automatically begins a 30-day trial.

lnSuccess = loCompress.UnlockComponent("30-day trial")
IF (lnSuccess <> 1) THEN
    =MESSAGEBOX("Compression component unlock failed")
    QUIT
ENDIF

loCompress.Algorithm = "ppmd"

*  Create a long string to compress.
lcStrData = "abcdefg1122334455667788"
lcStrData = lcStrData + CHR(13)+CHR(10)
FOR i = 0 TO 99
    lcStrData = lcStrData + "abcdefg1122334455667788"
    lcStrData = lcStrData + CHR(13)+CHR(10)
NEXT

*  Depending on the programming language, the string
*  may be Unicode.  Tell the component to convert to
*  ansi (1-byte/char) prior to compression:
loCompress.Charset = "ansi"

*  PPMD compress the string:

loCompressedBytes = loCompress.CompressString(lcStrData)

*  Decompress back to the original:

lcStrOriginal = loCompress.DecompressString(loCompressedBytes)

*  Display the uncompressed original:
? "--- Original ---"
? lcStrOriginal