Unit 'fpExprPars'	Package
[Overview][Constants][Types][Classes][Procedures and functions][Index]	[#fcl]

TFPExpressionScanner

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

Class for tokenizing expression strings into parser tokens

Declaration

Source position: fpexprpars.pp line 67

`type TFPExpressionScanner = class(TObject)`
`FSource: AnsiString;`
`LSource: Integer;`
`FPos: Integer;`
`FChar: PAnsiChar;`
`FToken: AnsiString;`
`FTokenType: TTokenType;`
`public`
`constructor Create; virtual;`		Create a new expression scanner
`function GetToken; virtual;`		Get the next token from the source expression
`procedure AddOperatorAlias();`
`procedure ClearOperatorAliases;`
`property OperatorAliases []: TOperatorAlias; [r]`
`property OperatorAliasCount: Integer; [r]`
`property StringQuoteChar: AnsiChar; [rw]`
`property IdentifierQuoteChar: AnsiChar; [rw]`
`property Token: AnsiString; [r]`		The text of the current token
`property TokenType: TTokenType; [r]`		The type of the current token
`property Source: AnsiString; [rw]`		The source expression string to scan
`property Pos: Integer; [r]`		Current position in the source string
`property CurrentChar: AnsiChar; [r]`		The current character being processed
`end;`

Inheritance

`TFPExpressionScanner`		Class for tokenizing expression strings into parser tokens
\|
`TObject`

Description

The TFPExpressionScanner class performs lexical analysis on expression strings, breaking them into tokens that can be consumed by the expression parser. It handles the low-level details of character recognition, string parsing, and token classification.

The scanner recognizes all token types defined in TTokenType including operators, literals, identifiers, keywords, and delimiters.

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