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

TFPExprFunction

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

Internally used class for representing function calls in expression trees

Declaration

Source position: fpexprpars.pp line 625

type TFPExprFunction = class(TFPExprIdentifierNode)

public

  procedure Check; override;

  

Validate the function expression

  constructor CreateFunction(); virtual;

  

Create function with identifier and arguments

  destructor Destroy; override;

  

Destroy function expression and free resources

  procedure InitAggregate; override;

  

Initialize aggregate processing for function

  procedure UpdateAggregate; override;

  

Update aggregate calculations for function

  function HasAggregate; override;

  

Check if function contains aggregates

  property ArgumentNodes: TExprArgumentArray; [r]

  

The argument nodes for the function

  property ArgumentParams: TExprParameterArray; [r]

  

The argument parameters for the function

  function AsString; override;

  

Get string representation of function expression

end;

Inheritance

TFPExprFunction

  

Internally used class for representing function calls in expression trees

|

TFPExprIdentifierNode

  

Internally used class for identifier nodes in expression trees

|

TFPExprNode

  

Class for representing nodes in expression trees

|

TObject

Description

The TFPExprFunction class represents a function call node in the expression tree. It serves as the base class for all function implementations that can be called from within expressions, including mathematical functions, string functions, date/time functions, and user-defined functions.

The class manages function parameters, validates argument types and counts, and provides the framework for function evaluation. It handles the common aspects of function calls such as parameter management and type checking.

Derived classes implement specific functions by overriding the evaluation methods and providing function-specific logic. The class supports functions with varying numbers of parameters and different return types.

This class is used internally by the TFPExpressionParser class to construct an AST (Abstract Syntax Tree). There is normally no need for you to use or instantiate this class directly.

See also

TFPExprNode

  

Class for representing nodes in expression trees


Documentation generated on: Dec 15 2025