Reference for package '#rtl'

TParser

[Properties (by Name)][Methods (by Name)][Events (by Name)]

Class to parse the contents of a stream containing text data.

Declaration

Source position: classesh.inc line 1774

Type
  TParser = class (TObject)
  private
    fStream : TStream;
    fBuf : PChar;
    fBufLen : Integer;
    fPos : Integer;
    fDeltaPos : Integer;
    fFloatType : Char;
    fSourceLine : Integer;
    fToken : Char;
    fEofReached : Boolean;
    fLastTokenStr : string;
    fLastTokenWStr : WideString;
    function GetTokenName(aTok: Char) : string;
    procedure LoadBuffer;
    procedure CheckLoadBuffer;
    procedure ProcessChar;
    function IsNumber : Boolean;
    function IsHexNum : Boolean;
    function IsAlpha : Boolean;
    function IsAlphaNum : Boolean;
    function GetHexValue(c: Char) : Byte;
    function GetAlphaNum : string;
    procedure HandleNewLine;
    procedure SkipBOM;
    procedure SkipSpaces;
    procedure SkipWhitespace;
    procedure HandleEof;
    procedure HandleAlphaNum;
    procedure HandleNumber;
    procedure HandleHexNumber;
    function HandleQuotedString : string;
    procedure HandleDecimalCharacter(var ascii: Boolean; 
                                    out WideChr: WideChar; 
                                    out StringChr: Char);
    procedure HandleString;
    procedure HandleMinus;
    procedure HandleUnknown;
  public
    constructor Create(Stream: TStream);
    destructor Destroy;  Override;
    procedure CheckToken(T: Char);
    procedure CheckTokenSymbol(const S: string);
    procedure Error(const Ident: string);
    procedure ErrorFmt(const Ident: string; const Args: Array of const);
    procedure ErrorStr(const Message: string);
    procedure HexToBinary(Stream: TStream);
    function NextToken : Char;
    function SourcePos : LongInt;
    function TokenComponentIdent : string;
    function TokenFloat : Extended;
    function TokenInt : Int64;
    function TokenString : string;
    function TokenWideString : WideString;
    function TokenSymbolIs(const S: string) : Boolean;
    FloatType : Char;
    SourceLine : Integer;
    Token : Char;
  end
  ;

Description

This class breaks a stream of text data in tokens. Its primary use is to help reading the contents of a form file (usually a file with dfm, xfm or lfm extension), and for this reason it isn't suitable to be used as a general parser.

The parser is always positioned on a certain token, whose type is stored in the Token property. Various methods are provided to obtain the token value in the desired format.

To advance to the next token, invoke NextToken method.

Members

Member Type Visibility Description
CheckLoadBuffer Method private
CheckToken Method public Checks whether the token if of the given type.
CheckTokenSymbol Method public Checks whether the token equals the given symbol
Create Method public Creates a new parser instance.
Destroy Method public Destroys the parser instance.
Error Method public Raises an EParserError exception with the given message
ErrorFmt Method public Raises an EParserError exception and formats the message.
ErrorStr Method public Raises an EParserError exception with the given message
fBuf Field private
fBufLen Field private
fDeltaPos Field private
fEofReached Field private
fFloatType Field private
fLastTokenStr Field private
fLastTokenWStr Field private
FloatType Property public The type of a float token.
fPos Field private
fSourceLine Field private
fStream Field private
fToken Field private
GetAlphaNum Method private
GetHexValue Method private
GetTokenName Method private
HandleAlphaNum Method private
HandleDecimalCharacter Method private
HandleEof Method private
HandleHexNumber Method private
HandleMinus Method private
HandleNewLine Method private
HandleNumber Method private
HandleQuotedString Method private
HandleString Method private
HandleUnknown Method private
HexToBinary Method public Writes hexadecimal data to a stream.
IsAlpha Method private
IsAlphaNum Method private
IsHexNum Method private
IsNumber Method private
LoadBuffer Method private
NextToken Method public Reads the next token and returns its type.
ProcessChar Method private
SkipBOM Method private
SkipSpaces Method private
SkipWhitespace Method private
SourceLine Property public Current source line number.
SourcePos Method public Returns the current position in the stream.
Token Property public The type of the current token.
TokenComponentIdent Method public Returns the path of a subcomponent starting from the current token.
TokenFloat Method public Returns the current token as a float.
TokenInt Method public Returns the current token as an integer.
TokenString Method public Returns the current token as a string.
TokenSymbolIs Method public Returns True if the token equals the given symbol.
TokenWideString Method public Returns the current token as a widestring

Inheritance

Class Description
TParser Class to parse the contents of a stream containing text data.

See also

Name Description
Char Character type (1 byte)
Char Character type (1 byte)
Char Character type (1 byte)
Char Character type (1 byte)
Char Character type (1 byte)
Integer A signed 16-bits integer
Integer A signed 16-bits integer
Integer A signed 16-bits integer
Integer A signed 16-bits integer
Integer A signed 16-bits integer
TParser.NextToken Reads the next token and returns its type.
TParser.Token The type of the current token.
TStream Base class for streams.
WideString UTF-16 widechar encoded unicode string