Declaration (antlraux package v0.2.1 API Specification)

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v0.2.1

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antlraux.context
Class Declaration

java.lang.Object
  |
  +--antlraux.context.Declaration

All Implemented Interfaces:: LexInfo

public class Declaration
extends java.lang.Object
implements LexInfo

Declarations are the basic contextual information unit.

A declaration is a set of related fields, representing an bit of contextual information that has to be inserted in a Scope. Some of these are mandatory and others are optional (can be null). Mandatory fields are

Optional fields are:

ast
initialValue
Lexical information fields: filename, line, column

Optional fields can be null.

The aim of this class may be better understood with an example. Let's imagine a language whose variables would be declared like in C:

    int a,b,c;

Then somewhere in the semantic analyzer some code would have to make something equivalent to this:

    Scope currentScope = getCurrentScope();
    currentScope.insert( new Declaration(VARIABLE, intTag, "a"));
    currentScope.insert( new Declaration(VARIABLE, intTag, "b"));
    currentScope.insert( new Declaration(VARIABLE, intTag, "c"));

Note that in this example we are ignoring optional fields; if possible, you should not!

Declarations are also valid for declaring types; this:

 class A {...}
 struct s {...}

Would trigger the generation of a code similar to:

    Type AClassType = getTypeForClass("A");
    currentScope.insert(new Declaration(CLASS, AClassType, "A"));
    Type sStructType = getTypeForStruct("s");
    currentScope.insert(new Declaration(STRUCT, sStructType, "s"));

Depending on how you implement the scoping system (with or without Context- see the comments on Scope for further information ) this codes will be on a subclass of Scope or Context.

Author:: Enrique José García Cota
See Also:: Context, Scope, Type

Field Summary

protected antlr.collections.AST ast
          The AST that originated the declaration.

protected int column
          Lexical information.

protected java.lang.String filename
          Lexical information.

protected antlr.collections.AST initialValue
          An initial value for the declaration.

protected int line
          Lexical information.

protected java.lang.String name
          The declaration name

protected int tag
          An integer used to store different "declaration types", such as PARAMETER, ATTRIBUTE or CLASS.

protected Type type
          The declaration Type.

Fields inherited from interface antlraux.util.LexInfo

DEFAULT_COLUMN, DEFAULT_FILENAME, DEFAULT_LINE

Constructor Summary

Declaration(int tag, Type t, java.lang.String name)


Declaration(int tag, Type t, java.lang.String name, antlr.collections.AST ast, antlr.collections.AST initialValue, LexInfo lexInfo)


Declaration(int tag, Type t, java.lang.String name, antlr.collections.AST ast, antlr.collections.AST initialValue, java.lang.String fileName, int line, int column)


Method Summary

void copyLexInfo(LexInfo from)
          Copies the lexical information from other LexInfo.

antlr.collections.AST getAST()


int getColumn()
          Get the column for this node

java.lang.String getFilename()
          Get the file name for this node

antlr.collections.AST getInitialValue()


java.lang.String getLexInfoString()
          Returns true if all the information (Filename:line:column) is valid; false otherwise.

int getLine()
          Get the line for this node

java.lang.String getName()


int getTag()


Type getType()


void initialize(Declaration other)


void setAST(antlr.collections.AST ast)


void setColumn(int column)
          Set the column for this node

void setFilename(java.lang.String fn)
          Sets the file name for this node.

void setInitialValue(antlr.collections.AST initialValue)


void setLine(int line)
          Set the line for this node

void setName(java.lang.String name)
          Accessor for name

void setTag(int tag)


void setType(Type t)
          Accessor for type

java.lang.String toString()


Methods inherited from class java.lang.Object

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

Field Detail

type

protected Type type

The declaration Type.

name

protected java.lang.String name

The declaration name

tag

protected int tag

An integer used to store different "declaration types", such as PARAMETER, ATTRIBUTE or CLASS.

ast

protected antlr.collections.AST ast

The AST that originated the declaration. Can be null

initialValue

protected antlr.collections.AST initialValue

An initial value for the declaration. Use it when modelling declarations that involve a certain initialization value (like variables initialized with an expression ):

       Declaration
      ______/\______
     /              \    
     int a  = 2 + 2 ;
             \__  __/
                \/
          Initial value

In declarations with no initializations, null or a type- dependent default value could be used.

I've left this member's type as an AST, so you can use your own; however, I strongly recomment using an instance of ExpressionAST for it.

filename

protected java.lang.String filename

Lexical information. Can be null

line

protected int line

Lexical information. Can be null

column

protected int column

Lexical information. Can be null

Constructor Detail

Declaration

public Declaration(int tag,
                   Type t,
                   java.lang.String name)

Declaration

public Declaration(int tag,
                   Type t,
                   java.lang.String name,
                   antlr.collections.AST ast,
                   antlr.collections.AST initialValue,
                   LexInfo lexInfo)

Declaration

public Declaration(int tag,
                   Type t,
                   java.lang.String name,
                   antlr.collections.AST ast,
                   antlr.collections.AST initialValue,
                   java.lang.String fileName,
                   int line,
                   int column)

Method Detail

setName

public void setName(java.lang.String name)

Accessor for name

Throws:: java.lang.IllegalArgumentException - if name==null

getName

public java.lang.String getName()

setType

public void setType(Type t)

Accessor for type

Throws:: java.lang.IllegalArgumentException - if null==t

setTag

public void setTag(int tag)

setAST

public void setAST(antlr.collections.AST ast)

setInitialValue

public void setInitialValue(antlr.collections.AST initialValue)

getAST

public antlr.collections.AST getAST()

getType

public Type getType()

getTag

public int getTag()