import java.util.*; /** * An interface for defining scopes and scoping rules for Minijava. */ public interface Scope { /** * @return the name of this scope. */ public String getScopeName(); /** * Where to look next for symbols; * @return the scope that contains this scope. */ public Scope getEnclosingScope(); /** * Define a symbol in the current scope * @param sym A symbol to be defined in this scope. */ public void define(Symbol sym); /** * Adds sym to a collection of initialied variables in this scope. * @param sym The symbol to be initialized */ public void initialize(Symbol sym); /** * Searches for the symbol in the scope. If this scope does not contain * a symbol with the symbolName, name, * return getEnclosingScope==null ? null : getEnclosingScope().lookup(name); * @param name the name of the symbol that you would like to lookup * @return the symbol that is being referenced, or null if it is * not in the symbol-table */ public Symbol lookup(String name); /** * Searches for the symbol in the current scope. * If this scope does not contain a symbol with the symbolName name, * return null; * @param name the name of the symbol that you would like to lookup * @return the symbol that is being referenced, * or null if it is not in the current scope. */ public Symbol lookupLocally(String name); /** * @param name the name of the symbol that may * or may not have been initialized * @return true if the symbol with the given name has been * initialized and false otherwise. */ public boolean hasBeenInitialized(String name); /** * @return a set of all of the initialized variables in the this scope. */ public Set getInitializedVariables(); /** ----------------------------------------------------------------- | Static methods don't need to be overwritten. | -------------------------------------------------------------------*/ /** * @param scope A Scope for which you want to know * the Klass that contains it. * @return the Klass that contains scope. * If a Method m is overwritten in a subclass, * getEnclosingKlass(m) returns the subclass */ public static Klass getEnclosingKlass(Scope scope){ while(!(scope instanceof Klass)){ scope=scope.getEnclosingScope(); } return (Klass)scope;//The outermost scope will always be a class. } /** * @param scope A scope for which you want to know the Method that contains it. * @return the Method that contains scope. */ public static Method getEnclosingMethod(Scope scope){ while(!(scope instanceof Method)){ scope = scope.getEnclosingScope(); } return (Method)scope; } }