scope.java

来自「plugin for eclipse」· Java 代码 · 共 249 行

package isis.anp.nesc.ot.scope;

import isis.anp.common.TNode;
import isis.anp.nesc.ot.NameConflictException;
import isis.anp.nesc.ot.types.CompoundType;
import isis.anp.nesc.ot.types.EnumType;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;



/*
 * Created on Apr 6, 2005
 *
 * TODO To change the template for this generated file go to
 * Window - Preferences - Java - Code Style - Code Templates
 */

/**
 * @author sallai
 *
 * TODO To change the template for this generated type comment go to
 * Window - Preferences - Java - Code Style - Code Templates
 */
public class Scope implements Symbol {
	ArrayList symbolList = new ArrayList();
	TNode defNode;
	SymbolTraits symbol = new SymbolTraits();
	
	/**
	 * @param newScopeName
	 */
	public Scope(String name, Scope parent) {
		setName(name);
//		System.out.println("Creating scope "+getHierarchicalName());
		if(parent!=null) {
			parent.addSymbol(this);
		}		
	}
	
	/**
	 * @return Returns the children.
	 */
	public List getSymbolList() {
		return symbolList;
	}

	public String toString() {
		StringBuffer rval = new StringBuffer();
		rval.append("scope   ");
		rval.append(getHierarchicalName());
		rval.append("\n");
		
		Iterator j = symbolList.iterator();		
		while(j.hasNext()) {
			Symbol s = (Symbol) j.next();
			rval.append(s.toString());
			rval.append("\n");
		}
		
		return rval.toString();
	}
	
	public String getHierarchicalName() {
		return symbol.getHierarchicalName();
	}

	public Scope getRootScope() {
		if(getParentScope()==null) {
			return this;
		} else {
			return getParentScope().getRootScope();
		}
	}
	
	public void addSymbol(Symbol s) {
		// symbol has no name: we don't put it into the scope
		if(s.getName()==null) return;
		
		s.setParentScope(this);		
//		System.out.println("Adding Symbol: "+s.toString());
		symbolList.add(s);
	}
	
	public void removeSymbol(Symbol s) {
		symbolList.remove(s);
	}

	public void addSymbols(Collection symbols) {
		Iterator i = symbols.iterator();
		while (i.hasNext()) {
			Symbol s = (Symbol) i.next();
			addSymbol(s);
		}
	}
	

	/**
	 * Find a symbol recursively.
	 * @param symbolName the name of the symbol.
	 * @return The symbol object, or null if not found.
	 */
	public Symbol findSymbol(String symbolName) {
		Symbol position = null;
		
		if(!symbolList.isEmpty()) {
			position = (Symbol)this.symbolList.get(symbolList.size()-1);
		}
		
		// if no position is given, we start searching backwards from the last symbol
		return findSymbol(symbolName, position);
	}
	
	/**
	 * Find a symbol recursively.
	 * @param symbolName The name of the symbol.
	 * @param position The position in the currect scope at which to start the search.
	 * If position is null, search starts in parent scope (at the position of the current scope)
	 * @return The symbol object, or null if not found.
	 */
	public Symbol findSymbol(String symbolName, Symbol position) {
		Symbol rval = null;
		
		// try to look it up in the current scope
		rval = findSymbolInCurrentScope(symbolName, position);
		if(rval == null) {
			// recursively search in parent scope
			if(getParentScope()!=null) {
				rval = getParentScope().findSymbol(symbolName, this);
			}
		}
		
		return rval;
	}
	
	/**
	 * Search for the symbol in the current scope looking backwards.
	 * @param symbol The name of the symbol.
	 * @return The symbol object, or null if not found.
	 */
	public Symbol findSymbolInCurrentScope(String symbol) {
		if(symbolList.isEmpty()) return null;
		
		// if no position is given, we start searching backwards from the last symbol
		return findSymbolInCurrentScope(symbol, (Symbol)this.symbolList.get(symbolList.size()-1));
	};

	/**
	 * Search for the symbol in the current scope looking backwards, starting from
	 * the last index of the symbol given in position.
	 * @param symbol The name of the symbol.
	 * @param position The position to start search at.
	 * @return The symbol object, or null if not found.
	 */
	public Symbol findSymbolInCurrentScope(String symbol, Symbol position) {
		boolean positionReached = false;
		
		if(position == null) return null;
		
		for(int i=symbolList.lastIndexOf(position); i>=0; --i) {
			Symbol s = (Symbol) symbolList.get(i);
			if(s == position) {
				positionReached = true;
			}
			if(positionReached && s.getName().equals(symbol)) return s;
		}
		return null;
	}

	public void setNameNode(TNode nameNode) {
		this.symbol.setNameNode(nameNode);
	}

	public TNode getNameNode() {
		return this.symbol.getNameNode();
	}

	public void setName(String name) {
		this.symbol.setName(name);
	}

	public String getName() {
		return this.symbol.getName();
	}


	public void setParentScope(Scope parentScope) {
		this.symbol.setParentScope(parentScope);
	}


	public Scope getParentScope() {
		return this.symbol.getParentScope();
	}

	public void add(CompoundType ct) {

		// complete declaration with name given
		if(ct.getNameNode()!=null && ct.isComplete()) {
			// look for the symbol in current scope
			CompoundType prev = (CompoundType)this.findSymbolInCurrentScope(ct.getName());
			
			if(prev!=null && prev.isComplete()) {
				// error: this type is already defined
				NameConflictException ex = new NameConflictException(prev, this);
//				ctx.addError(new Error(ex, ex.getMessage(), new CodeLocation(ct.getNameNode()))) ;				
			} else {
				// add it to the scope
				this.addSymbol(ct);
				if(ct instanceof EnumType) {
					this.addSymbols(((EnumType)ct).getEnumeratorList());
				}
			}

			return;
		}
		
		// complete declaration with no name given
		if(ct.getNameNode()==null && ct.isComplete()) {
			if(ct instanceof EnumType) {
				this.addSymbols(((EnumType)ct).getEnumeratorList());
			}
			return;
		}

		// incomplete declaration
		if(ct.getNameNode()!=null && !ct.isComplete()) {
			
			// look for the symbol in scope
			CompoundType prev = (CompoundType) this.findSymbol(ct.getName());
			if(prev == null) {
				// this type is declared here first
				this.addSymbol(ct);
			} else {
				// error: this type is already defined
				NameConflictException ex = new NameConflictException(prev, this);
//				ctx.addError(new Error(ex, ex.getMessage(), new CodeLocation(ct.getNameNode()))) ;				
			}
			return;
		}
		
		// we should never get here...
	}
	
}