Validate the expression node for correctness
Source position: fpexprpars.pp line 120
public procedure TFPExprNode.Check; virtual; abstract; |
The Check abstract method must be implemented by derived classes to validate the expression node and its operands or parameters. It performs type checking, verifies that required operands are present, and ensures that the node can be safely evaluated.
The validation process typically includes checking operand types for compatibility, verifying function parameter counts and types, and ensuring that all required references (variables, functions) are available. If validation fails, appropriate exceptions must be raised.
The Check method is called during the expression preparation phase, before evaluation begins, to catch errors early and provide meaningful error messages.