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

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