cetus.hir

Interface Traversable

All Superinterfaces:

Printable

All Known Subinterfaces:

Annotatable, Loop, SymbolTable

All Known Implementing Classes:

AccessExpression, AccessLevel, AlignofExpression, AnnotationDeclaration, AnnotationStatement, ArrayAccess, AssignmentExpression, BinaryExpression, BooleanLiteral, BreakStatement, Case, CharLiteral, ClassDeclaration, CommaExpression, CompoundLiteral, CompoundStatement, ConditionalExpression, ConstructorInitializer, ContinueStatement, Declaration, DeclarationStatement, Declarator, Default, DeleteExpression, DestructorID, DoLoop, Enumeration, EscapeLiteral, ExceptionHandler, Expression, ExpressionStatement, FloatLiteral, ForLoop, FunctionCall, GotoStatement, Identifier, IDExpression, IfStatement, InfExpression, Initializer, IntegerLiteral, Label, LinkageSpecification, ListInitializer, Literal, MinMaxExpression, NameID, Namespace, NamespaceAlias, NestedDeclarator, NewExpression, NullStatement, OffsetofExpression, OperatorID, PreAnnotation, Procedure, ProcedureDeclarator, Program, QualifiedID, RangeExpression, ReturnStatement, SizeofExpression, SomeExpression, Statement, StatementExpression, StringLiteral, SwitchStatement, TemplateDeclaration, TemplateID, ThrowExpression, TranslationUnit, Typecast, UnaryExpression, UsingDeclaration, UsingDirective, VaArgExpression, ValueInitializer, VariableDeclaration, VariableDeclarator, WhileLoop

public interface Traversable
extends Printable

Any class implementing this interface can act as a tree node by providing access to its children and parent.

Method Summary

Methods

Modifier and Type	Method and Description
java.util.List<Traversable>	getChildren() Provides access to the children of this object as a list.
Traversable	getParent() Provides access to the parent of this object.
void	removeChild(Traversable child) Removes the specified child.
void	setChild(int index, Traversable t) Sets the indexth child of this object to t.
void	setParent(Traversable t) Sets the parent of this object.

Methods inherited from interface cetus.hir.Printable

print

Method Detail

getChildren

java.util.List<Traversable> getChildren()

Provides access to the children of this object as a list. This object is free to internally implement its list as a LinkedList or an ArrayList. It is generally not good practice to call this method yourself; the ordering of children is not guaranteed so instead you should use the methods of the particular class whose children you wish to access.

Returns:

the children as a list.

getParent

Traversable getParent()

Provides access to the parent of this object. Every IR object has at most one parent. (The parent relationship is the same as the parent relationship in the parse tree, and is not to be confused with the base class of a derived class declaration.)

Returns:

the parent of this object.

removeChild

void removeChild(Traversable child)

Removes the specified child.

Parameters:

child - a reference to a child object that must match with ==.

Throws:

NotAChildException - if the child does not exist.

java.lang.UnsupportedOperationException - if the child exists but the parent refuses to let it go. For instance, a BinaryExpression may refuse to remove its left side expression because that would lead to invalid IR. The only way to change a child of such an expression is to replace it.

setChild

void setChild(int index,
            Traversable t)

Sets the indexth child of this object to t. By calling this method, the old child located at the position i will have a null parent. It is generally not good practice to call this method yourself; the ordering of children is not guaranteed so instead you should use the methods of the particular class whose children you wish to access. There are checks to prevent such actions as making a statement a child of an expression, but you still may be able to do some damage with this method if you are not careful.

Throws:

NotAnOrphanException - if t already has a parent.

java.lang.IllegalArgumentException - if the type of the new child would violate a class invariant by becoming the indexth child.

setParent

void setParent(Traversable t)

Sets the parent of this object. Cetus checks that the parent already considers this object a child. The intent is to maintain an ordering where first this object becomes a child of another object, and then this object is told who its parent is. Enforcing this order makes it easier for Cetus to enforce other invariants and ensure the IR is correct.

Throws:

NotAChildException - if the parent does not already consider this object a child.

java.lang.IllegalArgumentException - (possibly) if the type of the parent would violate a class invariant. Not all classes perform this check because, for example, Expressions can appear as children of so many things that it is simply not worth checking.