diff options
| -rw-r--r-- | unicode/src/base/UUnicodeUtils.pas | 143 |
1 files changed, 130 insertions, 13 deletions
diff --git a/unicode/src/base/UUnicodeUtils.pas b/unicode/src/base/UUnicodeUtils.pas index 26f240a9..d34cd432 100644 --- a/unicode/src/base/UUnicodeUtils.pas +++ b/unicode/src/base/UUnicodeUtils.pas @@ -58,6 +58,9 @@ function IsPunctuationChar(ch: UCS4Char): boolean; overload; function IsControlChar(ch: WideChar): boolean; overload; function IsControlChar(ch: UCS4Char): boolean; overload; +function IsPrintableChar(ch: WideChar): boolean; overload; +function IsPrintableChar(ch: UCS4Char): boolean; overload; + {** * Checks if the given string is a valid UTF-8 string. * If an ANSI encoded string (with char codes >= 128) is passed, the @@ -67,6 +70,21 @@ function IsControlChar(ch: UCS4Char): boolean; overload; function IsUTF8String(const str: AnsiString): boolean; {** + * Iterates over an UTF-8 encoded string. + * StrPtr will be increased to the beginning of the next character on each + * call. + * Results true if the given string starts with an UTF-8 encoded char. + *} +function NextCharUTF8(var StrPtr: PAnsiChar; out Ch: UCS4Char): boolean; + +{** + * Deletes Count chars (not bytes) beginning at position Index. + * Index values start with 1. + *} +procedure UTF8Delete(var Str: UTF8String; Index: Integer; Count: Integer); +procedure UCS4Delete(var Str: UCS4String; Index: Integer; Count: Integer); + +{** * Checks if the string is composed of ASCII characters. *} function IsASCIIString(const str: AnsiString): boolean; @@ -118,9 +136,14 @@ function UCS4UpperCase(const str: UCS4String): UCS4String; overload; function UCS4CharToString(ch: UCS4Char): UCS4String; {** - * Copies a segment of str starting with Index with Count characters. + * Copies a segment of str starting with Index (1-based) with Count characters (not bytes). + *} +function UTF8Copy(const str: UTF8String; Index: Integer = 1; Count: Integer = -1): UTF8String; + +{** + * Copies a segment of str starting with Index (0-based) with Count characters. * Note: Do not use Copy() to copy UCS4Strings as the result will not contain - * a trailing #0 character and hence is invalid. + * a trailing #0 character and hence is invalid. *} function UCS4Copy(const str: UCS4String; Index: Integer = 0; Count: Integer = -1): UCS4String; @@ -225,8 +248,18 @@ begin Result := IsControlChar(WideChar(Ord(ch))); end; +function IsPrintableChar(ch: WideChar): boolean; +begin + Result := not IsControlChar(ch); +end; -function IsUTF8String(const str: AnsiString): boolean; +function IsPrintableChar(ch: UCS4Char): boolean; +begin + Result := IsPrintableChar(WideChar(Ord(ch))); +end; + + +function NextCharUTF8(var StrPtr: PAnsiChar; out Ch: UCS4Char): boolean; // find the most significant zero bit (Result: [7..-1]) function FindZeroMSB(b: byte): integer; @@ -243,42 +276,89 @@ function IsUTF8String(const str: AnsiString): boolean; end; var - I: integer; ZeroBit: integer; SeqCount: integer; // number of trailing bytes to follow +const + Mask: array[1..3] of byte = ($1F, $0F, $07); begin Result := false; SeqCount := 0; + Ch := 0; - for I := 1 to Length(str) do + while (StrPtr^ <> #0) do begin - if (str[I] >= #128) then + if (StrPtr^ < #128) then begin - ZeroBit := FindZeroMSB(Ord(str[I])); + // check that no more trailing bytes are expected + if (SeqCount = 0) then + begin + Ch := Ord(StrPtr^); + Inc(StrPtr); + Result := true; + end; + Break; + end + else + begin + ZeroBit := FindZeroMSB(Ord(StrPtr^)); // trailing byte expected if (SeqCount > 0) then begin // check if trailing byte has pattern 10xxxxxx if (ZeroBit <> 6) then - Exit; + begin + Inc(StrPtr); + Break; + end; + Dec(SeqCount); + Ch := (Ch shl 6) or (Ord(StrPtr^) and $3F); + + // check if char is finished + if (SeqCount = 0) then + begin + Inc(StrPtr); + Result := true; + Break; + end; end else // leading byte expected begin // check if pattern is one of 110xxxxx/1110xxxx/11110xxx if (ZeroBit > 5) or (ZeroBit < 3) then - Exit; + begin + Inc(StrPtr); + Break; + end; // calculate number of trailing bytes (1, 2 or 3) SeqCount := 6 - ZeroBit; + // extract first part of char + Ch := Ord(StrPtr^) and Mask[SeqCount]; end; end; + + Inc(StrPtr); end; - // trailing bytes missing? - if (SeqCount > 0) then - Exit; + if (not Result) then + Ch := Ord('?'); +end; +function IsUTF8String(const str: AnsiString): boolean; +var + Ch: UCS4Char; + StrPtr: PAnsiChar; +begin Result := true; + StrPtr := PChar(str); + while (StrPtr^ <> #0) do + begin + if (not NextCharUTF8(StrPtr, Ch)) then + begin + Result := false; + Exit; + end; + end; end; function IsASCIIString(const str: AnsiString): boolean; @@ -314,12 +394,14 @@ end; function LengthUTF8(const str: UTF8String): integer; begin - Result := Length(UTF8ToUCS4String(str)); + Result := LengthUCS4(UTF8ToUCS4String(str)); end; function LengthUCS4(const str: UCS4String): integer; begin Result := High(str); + if (Result = -1) then + Result := 0; end; function UTF8CompareStr(const S1, S2: UTF8String): integer; @@ -387,6 +469,11 @@ begin Result[1] := 0; end; +function UTF8Copy(const str: UTF8String; Index: Integer; Count: Integer): UTF8String; +begin + Result := UCS4ToUTF8String(UCS4Copy(UTF8ToUCS4String(str), Index-1, Count)); +end; + function UCS4Copy(const str: UCS4String; Index: Integer; Count: Integer): UCS4String; var I: integer; @@ -407,6 +494,36 @@ begin Result[Count] := 0; end; +procedure UTF8Delete(var Str: UTF8String; Index: Integer; Count: Integer); +var + StrUCS4: UCS4String; +begin + StrUCS4 := UTF8ToUCS4String(str); + UCS4Delete(StrUCS4, Index-1, Count); + Str := UCS4ToUTF8String(StrUCS4); +end; + +procedure UCS4Delete(var Str: UCS4String; Index: Integer; Count: Integer); +var + Len: integer; + OldStr: UCS4String; + I: integer; +begin + Len := LengthUCS4(Str); + if (Count <= 0) or (Index < 0) or (Index >= Len) then + Exit; + if (Index + Count > Len) then + Count := Len-Index; + + OldStr := Str; + SetLength(Str, Len-Count+1); + for I := 0 to Index-1 do + Str[I] := OldStr[I]; + for I := Index+Count to Len-1 do + Str[I-Count] := OldStr[I]; + Str[High(Str)] := 0; +end; + function WideStringUpperCase(ch: WideChar): WideString; begin // If WideChar #0 is converted to a WideString in Delphi, a string with |