TFPExprNode class

In unit fpExprPars

Class for representing nodes in expression trees

Declaration

pascal

TFPExprNode = class(TObject)

Inheritance

TFPExprNode
TObject

Descends from it: TCaseOperation TFPBinaryOperation TFPConstExpression TFPExprIdentifierNode TFPUnaryOperator

Description

This is the abstract base class for all nodes in the expression tree. Every element of a parsed expression (literals, variables, operators, functions) is represented by a class derived from TFPExprNode.

The class defines the common interface that all expression nodes must implement, including evaluation, type checking, and aggregate processing. It provides the foundation for building complex expression trees through composition of different node types.

Derived classes implement specific functionality for different types of expression elements such as arithmetic operations, function calls, variable references, and literal values.

Methods

`CheckNodeType`	protected
`GetNodeValue`	protected
`Check`	public	Validate the expression node for correctness
`InitAggregate`	public	Initialize aggregate processing for the node
`UpdateAggregate`	public	Update aggregate calculations for the node
`IsAggregate`	public	Check if this node represents an aggregate operation
`HasAggregate`	public	Check if node tree contains any aggregate operations
`NodeType`	public	Get the result type of this expression node
`NodeValue`	public	Get the evaluated value of this expression node
`AsString`	public	Get string representation of the expression node

Inherited

From TObject (42)

AfterConstruction BeforeDestruction CheckDisposed ClassInfo ClassName ClassNameIs ClassParent ClassType CleanupInstance Create DefaultHandler DefaultHandlerStr Destroy Dispatch DispatchStr Disposed DisposeOf Equals FieldAddress Free FreeInstance GetDisposed GetHashCode GetInterface GetInterfaceByStr GetInterfaceEntry GetInterfaceEntryByStr GetInterfaceTable GetInterfaceWeak GetLastCastErrorInfo InheritsFrom InitInstance InstanceSize MethodAddress MethodName newinstance QualifiedClassName SafeCallException StringMessageTable SystemHasExtendedRTTI ToString UnitName

An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.