Unreal Engine 4.26 Documentation

Unreal Engine 4.27 Documentation

Unreal Engine 5.0 Documentation

Unreal Engine 5.1 Documentation

Unreal Engine 5.2 Documentation

Unreal Engine 5.3 Documentation

> Unreal Engine API Reference > Developer > RigVMDeveloper > RigVMCompiler > FRigVMExprAST

Light Theme

Dark Theme

FRigVMExprAST

Base class for an expression within an abstract syntax tree.

Windows

MacOS

Linux

Inheritance Hierarchy

FRigVMExprAST

FRigVMAssignExprAST

FRigVMCopyExprAST

FRigVMBlockExprAST

FRigVMNodeExprAST

	FRigVMBranchExprAST
	FRigVMCallExternExprAST
	FRigVMEntryExprAST
	FRigVMIfExprAST
	FRigVMNoOpExprAST
	FRigVMSelectExprAST

FRigVMCachedValueExprAST

FRigVMExitExprAST

FRigVMVarExprAST

FRigVMLiteralExprAST

References

Module	RigVMDeveloper
Header	/Engine/Source/Developer/RigVMDeveloper/Public/RigVMCompiler/RigVMAST.h
Include	#include "RigVMCompiler/RigVMAST.h"

Syntax

class FRigVMExprAST

Remarks

Base class for an expression within an abstract syntax tree. The base implements parent / child relationships as well as a simple typing system. An expression is a multi child / multi parent element of a directed tree (there can be no cycles). Expressions can only be constructed by an AST parser, and are also memory-owned by the parser.

Constructors

	Name	Description
	FRigVMExprAST ( const FRigVMExprAST& )	Disable copy constructor
	FRigVMExprAST ( EType InType, UObject* InSubject )	Default constructor (protected so that only parser can access it)

Destructors

	Name	Description
	~FRigVMExprAST()	Virtual destructor

Functions

	Name	Description
void	AddParent ( FRigVMExprAST* InParent )	Adds a parent to this expression this in consequence also adds this as a child to the parent
TArray< FRig...	begin()	Begin iterator accessor for the children
const Object...	ChildAt ( int32 InIndex )	Templated getter to retrieve a child with a given index type checking will occur within the ::To method and raise
const FRigVM...	ChildAt ( int32 InIndex )	Getter to retrieve a child with a given index
TArray< FRig...	end()	End iterator accessor for the children
const FRigVM...	GetBlock()	Returns the block of this expression
const FRigVM...	GetFirstChildOfType ( EType InExprType )	Returns the first parent in the tree of a given type
const FRigVM...	GetFirstParentOfType ( EType InExprType )	Returns the first parent in the tree of a given type
int32	GetIndex()	Returns the index of this expression within the parser's storage
int32	GetMinChildIndexWithinParent ( const FRigVMExprAST* InParentE... )	Returns the lowest child index found for this expression within a parent (or INDEX_NONE)
FName	GetName()	Returns the name of the expression (can be NAME_None)
const FRigVM...	GetParent()	Returns the parent of this expression
const FRigVM...	GetParser()	Returns the parser this expression is owned by
const FRigVM...	GetRootBlock()	Returns the root / top level block of this expression
EType	GetType()	Returns the exact type of the expression
FName	GetTypeName()	Returns the name of the expression's type
bool	IsA ( EType InType )	Provides type checking for inherited types
bool	IsConstant()	Returns true if this expressions is constant (non varying)
bool	IsVarying()	Returns true if this expressions is varying (non constant)
int32	NumChildren()	Returns the number of children of this expression
int32	NumParents()	Returns the number of parents of this expression
const FRigVM...	ParentAt ( int32 InIndex )	Getter to retrieve a parent with a given index
const Object...	ParentAt ( int32 InIndex )	Templated getter to retrieve a parent with a given index type checking will occur within the ::To method and raise
void	RemoveChild ( FRigVMExprAST* InChild )	Removes a child from this expression this in consequence also removes this as a parent from the child
void	RemoveParent ( FRigVMExprAST* InParent )	Removes a parent from this expression this in consequence also removes this as a child from the parent
void	ReplaceBy ( FRigVMExprAST* InReplacement )	Replaces this expression with another one
void	ReplaceChild ( FRigVMExprAST* InCurrentChild, FRigVMExprAST* InNewChild )	Replaces a child of this expression with a new one
void	ReplaceParent ( FRigVMExprAST* InCurrentParent, FRigVMExprAST* InNewParent )	Replaces a parent of this expression with a new one
const FRigVM...	To()	Specialized cast for type checking for a Branch / FRigVMBranchExprAST expression will raise if types are not compatible
const FRigVM...	To()	Specialized cast for type checking for a Exit / FRigVMExitExprAST expression will raise if types are not compatible
const FRigVM...	To()	Specialized cast for type checking for a CachedValue / FRigVMCachedValueExprAST expression will raise if types are not compatible
const FRigVM...	To()	Specialized cast for type checking for a Copy / FRigVMCopyExprAST expression will raise if types are not compatible
const FRigVM...	To()	Specialized cast for type checking for a Assign / FRigVMAssignExprAST expression will raise if types are not compatible
const FRigVM...	To()	Specialized cast for type checking for a Literal / FRigVMLiteralExprAST expression will raise if types are not compatible
const FRigVM...	To()	Specialized cast for type checking for a Var / FRigVMVarExprAST expression will raise if types are not compatible
const FRigVM...	To()	Specialized cast for type checking for a CallExtern / FRigVMCallExternExprAST expression will raise if types are not compatible
const FRigVM...	To()	Specialized cast for type checking for a Entry / FRigVMEntryExprAST expression will raise if types are not compatible
const FRigVM...	To()	Specialized cast for type checkiFRigVMAssignExprASTng for a Block / FRigVMBlockExprAST expression will raise if types are not compatible
ObjectType &...	To()	Templated cast for casting between different expression types.
const Object...	To()	Const templated cast for casting between different expression types.
const FRigVM...	To()	Specialized cast for type checking for a If / FRigVMIfExprAST expression will raise if types are not compatible
const FRigVM...	To()	Specialized cast for type checking for a NoOp / FRigVMNoOpExprAST expression will raise if types are not compatible
const FRigVM...	To()	Specialized cast for type checking for a Select / FRigVMSelectExprAST expression will raise if types are not compatible

Operators

		Name	Description
	const FRigVM...	operator[] ( int32 InIndex )	Accessor operator for a given child

Enums

	Name	Description
	EType	Simple enum for differentiating expression types.

Help shape the future of Unreal Engine documentation! Tell us how we're doing so we can serve you better.

Take our survey

Dismiss