serene-simple/src/main/java/serene/simple/BaseScope.java

54 lines
1.7 KiB
Java

/**
* Serene (simple) - A PoC lisp to collect data on Serenes concepts
* Copyright (C) 2019-2020 Sameer Rahmani <lxsameer@gnu.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
package serene.simple;
import java.util.HashMap;
import java.util.Map;
public abstract class BaseScope {
private final Map<String, Object> symbolsMapping = new HashMap<String, Object>();
private final BaseScope parent;
public BaseScope() {
this(null);
}
public BaseScope(BaseScope parent) {
this.parent = parent;
}
public Object lookupSymbol(String symbolName) {
if (this.symbolsMapping.containsKey(symbolName)) {
return this.symbolsMapping.get(symbolName);
}
else if (this.parent != null) {
return this.parent.lookupSymbol(symbolName);
}
else {
throw new RuntimeException(String.format("Symbol '%s' is not defined in this scope.",
symbolName));
}
}
public void insertSymbol(String symbolName, Object symbolValue) {
this.symbolsMapping.put(symbolName, symbolValue);
}
}