edu.jmu.decaf

Class ASTNode

java.lang.Object

edu.jmu.decaf.ASTNode

Direct Known Subclasses:

ASTBlock, ASTExpression, ASTFunction, ASTProgram, ASTStatement, ASTVariable

public abstract class ASTNode
extends Object

Abstract base class for abstract syntax tree (AST) nodes. Provides some basic definitions used across many nodes, such as ASTNode.DataType definitions and attribute management. AST nodes are designed to be semi-mutable by means of the attributes map that is stored in every node. Several of the more important attributes (e.g., parent links and tree depth) are widely used and thus have special handlers implemented in this class. However, this class is not intended to be instantiated directly, and thus is declared abstract. List of potential attributes (not exhaustive):

Potential attributes

Key	Description
parent	Uptree parent ASTNode reference
depth	Tree depth (int)
source	SourceInfo reference
symbolTable	SymbolTable reference (only in ASTProgram, ASTFunction, and ASTBlock)
type	ASTNode.DataType of node (only in ASTExpression subclasses)
staticSize	Size (in bytes) of global variables (only in ASTProgram)
localSize	Size (in bytes) of local variables (only in ASTFunction)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ASTNode.DataType List of Decaf AST data types.

Field Summary

Fields

Modifier and Type	Field and Description
Map<String,Object>	attributes Generic key/value store.

Constructor Summary

Constructors

Constructor and Description
ASTNode() Generic constructor.

Method Summary

Modifier and Type	Method and Description
String	getASTTypeStr() Returns a string with the AST class type (mainly used for debugging)
int	getDepth() Retrieve the tree depth marker
ASTNode	getParent() Retrieve the uptree parent pointer
SourceInfo	getSourceInfo() Retrieve the source code information
ASTNode.DataType	getType() Retrieve the type
void	setDepth(int depth) Initialize the tree depth marker
void	setParent(ASTNode parent) Initialize the uptree parent pointer
void	setSourceInfo(SourceInfo source) Initialize source code information
void	setType(ASTNode.DataType type) Initialize type
void	traverse(ASTVisitor visitor) Generic traversal method for the visitor pattern.
static String	typeToString(ASTNode.DataType t) Returns a human-readable version of Decaf data types.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

attributes

public Map<String,Object> attributes

Generic key/value store. Used to annotate AST with useful properties. See class documentation for more details.

Constructor Detail

ASTNode

public ASTNode()

Generic constructor.

Method Detail

typeToString

public static String typeToString(ASTNode.DataType t)

Returns a human-readable version of Decaf data types.

Parameters:

t - Data type

Returns:

String version of given type

getASTTypeStr

public String getASTTypeStr()

Returns a string with the AST class type (mainly used for debugging)

Returns:

Short descriptor of the AST type

setParent

public void setParent(ASTNode parent)

Initialize the uptree parent pointer

Parameters:

parent - Parent AST object

getParent

public ASTNode getParent()

Retrieve the uptree parent pointer

Returns:

Parent ASTNode reference or null if the corresponding attribute is not present

setDepth

public void setDepth(int depth)

Initialize the tree depth marker

Parameters:

depth - Node depth

getDepth

public int getDepth()

Retrieve the tree depth marker

Returns:

Depth (as an integer) or -1 if the corresponding attribute is not present.

setSourceInfo

public void setSourceInfo(SourceInfo source)

Initialize source code information

Parameters:

source - Source info

getSourceInfo

public SourceInfo getSourceInfo()

Retrieve the source code information

Returns:

SourceInfo reference or SourceInfo.INVALID if the corresponding attribute is not present.

setType

public void setType(ASTNode.DataType type)

Initialize type

Parameters:

type - Node type

getType

public ASTNode.DataType getType()

Retrieve the type

Returns:

Node type

traverse

public void traverse(ASTVisitor visitor)

Generic traversal method for the visitor pattern. This will be overloaded by all child classes.

Parameters:

visitor - Visitor object