Application: gvSIG desktop

package org.gvsig.expressionevaluator.impl;

import java.util.HashMap;

import java.util.Iterator;

import java.util.Map;

import org.gvsig.expressionevaluator.Function;

import org.gvsig.expressionevaluator.SymbolTable;

import org.gvsig.expressionevaluator.MutableSymbolTable;

public class DefaultSymbolTable implements MutableSymbolTable {

    private SymbolTable delegatedSymbolTable;

    private Map<String,Object> vars;

    private Map<String,Function> functions;

    public DefaultSymbolTable(SymbolTable delegatedSymbolTable) {

        this.delegatedSymbolTable = delegatedSymbolTable;

        this.vars = new HashMap<>();

        this.functions = new HashMap<>();

    }

    public DefaultSymbolTable() {

        this(null);

    }

    @Override

    public MutableSymbolTable clone() throws CloneNotSupportedException {

        DefaultSymbolTable other = (DefaultSymbolTable) super.clone();

        if( this.delegatedSymbolTable!=null ) {

            other.delegatedSymbolTable = this.delegatedSymbolTable.clone();

        }

        other.vars = new HashMap<>(vars);

        other.functions = new HashMap<>(functions);

        return other;

    }

    @Override

    public void addVar(String name, Object value) {

        this.vars.put(name, value);

    }

    @Override

    public void addFunction(Function function) {

        this.functions.put(function.name(), function);

    }

    @Override

    public Function function(String name) {

        Function fn = this.functions.get(name);

        if( fn == null && this.delegatedSymbolTable != null ) {

            fn = this.delegatedSymbolTable.function(name);

        }

        return fn;

    }

    @Override

    public boolean exists(String name) {

        boolean e = this.vars.containsKey(name);

        if( !e ) {

            e = this.delegatedSymbolTable.exists(name);

        }

        return e;

    }

    @Override

    public Object value(String name) {

        if( this.vars.containsKey(name) ) {

            return this.vars.get(name);

        }

        return this.delegatedSymbolTable.value(name);

    }

    @Override

    public void setSymbolTable(SymbolTable symbolTable) {

        this.delegatedSymbolTable = symbolTable;

    }

    @Override

    public SymbolTable getSymbolTable() {

        return this.delegatedSymbolTable;

    }

    @Override

    public void removeVar(String name) {

        this.vars.remove(name);

    }

    @Override

    public void removeFunction(String name) {

        this.functions.remove(name);

    }

    @Override

    public Iterator<String> itervars() {

        return this.vars.keySet().iterator();

    }

    @Override

    public Iterator<Function> iterfuncs() {

        return this.functions.values().iterator();

    }

    @Override

    public Iterator<Function> iterator() {

        return iterfuncs();

    }

}