This is a proposal for its implementation. It tries to accommodate the difference in the nature of VFP and X# (.Net) strings. VFP strings are made of 8 bit ANSI or binary characters, X# strings are Unicode.
The main challenge is to provide the function's nuclear functionality while adding some value to the X# environment.
Some key points
- Conversion to Unicode or to DBCS strings return strings.
- Base64 and hexadecimal representations of data are treated as strings.
- Single-byte strings and UTF-8 are returned as Binary.
- Regional identifiers (may) affect single-byte and DBCS strings.
- Added two types that represent a Unicode string as a Binary (for LE and BE).
Code: Select all
USING System.Text
USING System.IO
USING System.Globalization
USING XSharp.Core
FUNCTION Start() AS VOID
LOCAL TextNr AS Int
TestNr = 1
// Base64
QuickTest(TestNr++, 'StrConv("Abcd", STRCNV_SB_BASE64)', StrConv("Abcd", STRCNV_SB_BASE64), "QWJjZA==")
QuickTest(TestNr++, 'StrConv("QWJjZA==", STRCNV_BASE64_SB)', StrConv("QWJjZA==", STRCNV_BASE64_SB), (Binary)"Abcd")
QuickTest(TestNr++, 'StrConv(0h010203fdfeff, STRCNV_SB_BASE64)', StrConv(0h010203fdfeff, STRCNV_SB_BASE64), "AQID/f7/")
QuickTest(TestNr++, 'StrConv("AQID/f7/", STRCNV_BASE64_SB)', StrConv("AQID/f7/", STRCNV_BASE64_SB), 0h010203fdfeff)
// Hex
QuickTest(TestNr++, 'StrConv("Abcd", STRCNV_SB_HEX)', StrConv("Abcd", STRCNV_SB_HEX), "41626364")
QuickTest(TestNr++, 'StrConv("41626364", STRCNV_HEX_SB)', StrConv("41626364", STRCNV_HEX_SB), (Binary)"Abcd")
QuickTest(TestNr++, 'StrConv(0h010203fdfeff, STRCNV_SB_HEX)', StrConv(0h010203fdfeff, STRCNV_SB_HEX), "010203FDFEFF")
QuickTest(TestNr++, 'StrConv("010203FDFEFF", STRCNV_HEX_SB)', StrConv("010203fdfeff", STRCNV_HEX_SB), 0h010203fdfeff)
// Unicode
QuickTest(TestNr++, 'StrConv(StrConv(StrConv("Привет мир!", STRCNV_UNI_DBCS, 1251, 1), STRCNV_DBCS_SB), STRCNV_SB_HEX)', ;
StrConv(StrConv(StrConv("Привет мир!", STRCNV_UNI_DBCS, 1251, 1), STRCNV_DBCS_SB), STRCNV_SB_HEX), "CFF0E8E2E5F220ECE8F021")
QuickTest(TestNr++, 'StrConv("Привет мир!", STRCNV_UNI_UTF8)', StrConv("Привет мир!", STRCNV_UNI_UTF8), 0hD09FD180D0B8D0B2D0B5D18220D0BCD0B8D18021)
QuickTest(TestNr++, 'StrConv(e"Belxc3xa9m do Parxc3xa1", STRCNV_UTF8_UNI)', StrConv(e"Belxc3xa9m do Parxc3xa1", STRCNV_UTF8_UNI), "Belém do Pará")
QuickTest(TestNr++, 'StrConv(0hC8, STRCNV_DBCS_UNI, 1253, 1) + StrConv(0hC8, STRCNV_DBCS_UNI, 1256, 1)', ;
StrConv(0hC8, STRCNV_DBCS_UNI, 1253, 1) + StrConv(0hC8, STRCNV_DBCS_UNI, 1256, 1), 'Θب')
// Extras
QuickTest(TestNr++, 'StrConv("Γειά σου Κόσμε!", STRCNV_UNI_SB)', StrConv("Γειά σου Κόσμε!", STRCNV_UNI_SB), 0h9303B503B903AC032000C303BF03C50320009A03CC03C303BC03B5032100)
WAIT
RETURN
FUNCTION QuickTest (Test AS Int, Expression AS String, Result AS USUAL, Expected AS USUAL) AS Void
? Test, Expression, "->", Result, "(" + IIF(Result == Expected, "Success", "Fail, was expecting " + Expected) + ")"
ENDFUNC
DEFINE STRCNV_SB_DBCS = 1
DEFINE STRCNV_DBCS_SB = 2
DEFINE STRCNV_KATA_HIRA = 3
DEFINE STRCNV_HIRA_KATA = 4
DEFINE STRCNV_DBCS_UNI = 5
DEFINE STRCNV_UNI_DBCS = 6
DEFINE STRCNV_LOWER = 7
DEFINE STRCNV_UPPER = 8
DEFINE STRCNV_DBCS_UTF8 = 9
DEFINE STRCNV_UNI_UTF8 = 10
DEFINE STRCNV_UTF8_DBCS = 11
DEFINE STRCNV_UTF8_UNI = 12
DEFINE STRCNV_SB_BASE64 = 13
DEFINE STRCNV_BASE64_SB = 14
DEFINE STRCNV_SB_HEX = 15
DEFINE STRCNV_HEX_SB = 16
DEFINE STRCNV_UNI_SB = 17
DEFINE STRCNV_UNIBE_SB = 18
DEFINE STRCNV_ID_LCID = 0
DEFINE STRCNV_ID_CODEPAGE = 1
DEFINE STRCNV_ID_CHARSET = 2
FUNCTION StrConv (Expression AS String, ConversionSetting AS Int, RegionalIdentifier = 0 AS Int, RegionalIDType = STRCNV_ID_LCID AS Int) AS USUAL
RETURN StrConv_Helper(Expression, (Binary)Expression, ConversionSetting, RegionalIdentifier, RegionalIDType)
END FUNCTION
FUNCTION StrConv (Expression AS Binary, ConversionSetting AS Int, RegionalIdentifier = 0 AS Int, RegionalIDType = STRCNV_ID_LCID AS Int) AS USUAL
RETURN StrConv_Helper((String)Expression, Expression, ConversionSetting, RegionalIdentifier, RegionalIDType)
END FUNCTION
FUNCTION StrConv (Expression AS USUAL, ConversionSetting AS Int, RegionalIdentifier = 0 AS Int, RegionalIDType = STRCNV_ID_LCID AS Int) AS USUAL
SWITCH VARTYPE(Expression)
CASE "C"
LOCAL StrExpression AS String
StrExpression = Expression
RETURN StrConv(StrExpression, ConversionSetting, RegionalIdentifier, RegionalIDType)
CASE "Q"
LOCAL BinExpression AS Binary
BinExpression = Expression
RETURN StrConv(BinExpression, ConversionSetting, RegionalIdentifier, RegionalIDType)
OTHERWISE
THROW ArgumentException{"Incorrect parameter.", nameof(Expression)}
END SWITCH
END FUNCTION
FUNCTION StrConvStr (Expression AS Binary, RegionalIdentifier = 0 AS Int, RegionalIDType = STRCNV_ID_LCID AS Int) AS String
VAR enc = StrConv_GetEncoding(RegionalIdentifier, RegionalIDType)
RETURN Encoding.Unicode.GetString(Encoding.Convert(enc, Encoding.Unicode, Expression))
END FUNCTION
STATIC FUNCTION StrConv_helper (Expression AS String, BinaryExpression AS Binary, ConversionSetting AS Int, RegionalIdentifier = 0 AS Int, RegionalIDType = STRCNV_ID_LCID AS Int) AS USUAL
LOCAL ReturnStr AS String
LOCAL ReturnBin AS Binary
LOCAL ReturnType AS String
LOCAL defenc = Encoding.Default AS System.Text.Encoding
LOCAL utf8 = Encoding.UTF8 AS System.Text.Encoding
LOCAL unicode = Encoding.Unicode AS System.Text.Encoding
LOCAL enc AS System.Text.Encoding
LOCAL Indexer AS Int
SWITCH (ConversionSetting)
CASE STRCNV_SB_DBCS
IF RegionalIDType == STRCNV_ID_LCID
enc = StrConv_GetEncoding(RegionalIdentifier, STRCNV_ID_LCID)
ReturnStr = defenc.GetString(Encoding.Convert(defenc, enc, BinaryExpression))
ReturnType = "S"
ELSE
THROW ArgumentException {}
END IF
CASE STRCNV_DBCS_SB
IF RegionalIDType == STRCNV_ID_LCID
enc = StrConv_GetEncoding(RegionalIdentifier, STRCNV_ID_LCID)
ReturnBin = Encoding.Convert(defenc, enc, BinaryExpression)
ReturnType = "B"
ELSE
THROW ArgumentException {}
END IF
CASE STRCNV_KATA_HIRA
ReturnStr = Expression // not implemented
ReturnType = "S"
CASE STRCNV_HIRA_KATA
ReturnStr = Expression // not implemented
ReturnType = "S"
CASE STRCNV_DBCS_UNI
enc = StrConv_GetEncoding(RegionalIdentifier, RegionalIDType)
ReturnStr = unicode.GetString(Encoding.Convert(enc, unicode, BinaryExpression))
ReturnType = "S"
CASE STRCNV_UNI_DBCS
enc = StrConv_GetEncoding(RegionalIdentifier, RegionalIDType)
ReturnStr = defenc.GetString(Encoding.Convert(unicode, enc, unicode.GetBytes(Expression)))
ReturnType = "S"
CASE STRCNV_LOWER
IF RegionalIDType == STRCNV_ID_LCID
ReturnBin = defenc.GetBytes(defenc.GetString(BinaryExpression).ToLower(StrConv_GetCulture(RegionalIdentifier)))
ReturnType = "B"
ELSE
THROW ArgumentException {}
END IF
CASE STRCNV_UPPER
IF RegionalIDType == STRCNV_ID_LCID
ReturnBin = defenc.GetBytes(defenc.GetString(BinaryExpression).ToUpper(StrConv_GetCulture(RegionalIdentifier)))
ReturnType = "B"
ELSE
THROW ArgumentException {}
END IF
CASE STRCNV_DBCS_UTF8
enc = StrConv_GetEncoding(RegionalIdentifier, RegionalIDType)
ReturnBin = Encoding.Convert(enc, Encoding.UTF8, BinaryExpression)
ReturnType = "B"
CASE STRCNV_UNI_UTF8
ReturnBin = Encoding.Convert(unicode, utf8, unicode.GetBytes(Expression))
ReturnType = "B"
CASE STRCNV_UTF8_DBCS
enc = StrConv_GetEncoding(RegionalIdentifier, RegionalIDType)
ReturnStr = defenc.GetString(Encoding.Convert(Encoding.UTF8, enc, BinaryExpression))
ReturnType = "S"
CASE STRCNV_UTF8_UNI
ReturnStr = unicode.GetString(Encoding.Convert(Encoding.UTF8, Encoding.Unicode, BinaryExpression))
ReturnType = "S"
CASE STRCNV_SB_BASE64
ReturnStr = Convert.ToBase64String(BinaryExpression)
ReturnType = "S"
CASE STRCNV_BASE64_SB
ReturnBin = Convert.FromBase64String(defenc.GetString(BinaryExpression))
ReturnType = "B"
CASE STRCNV_SB_HEX
ReturnStr = SUBSTR(BinaryExpression.ToString(), 3)
ReturnType = "S"
CASE STRCNV_HEX_SB
VAR SingleBytes = Byte[]{Expression.Length / 2}
LOCAL Hex AS Int
Hex = 0
FOR Indexer = 1 TO SingleBytes.Length
SingleBytes[Indexer] = Convert.ToByte(Expression.Substring(Hex, 2), 16)
Hex += 2
NEXT
ReturnBin = SingleBytes
R