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package tinybasic;
import java.util.*;
public class Context {
protected Scope theGlobalScope=null;
protected Scope theProgramScope=null;
protected Stack theScopeStack;
Hashtable subroutineTable;
Hashtable functionTable;
public Context(){
theGlobalScope=new GlobalScope(null);
theScopeStack=new Stack();
theScopeStack.push(theGlobalScope);
subroutineTable = new Hashtable();
functionTable = new Hashtable();
}
void insertSubroutine(String v,DTCodeType t){
subroutineTable.put(v.toLowerCase(),t);
}
public DTCodeType getSubroutine(String v){
DTCodeType t=(DTCodeType)subroutineTable.get(v.toLowerCase());
return t;
}
void insertFunction(String v,DTCodeType t){
functionTable.put(v.toLowerCase(),t);
}
public DTCodeType getFunction(String v){
DTCodeType t=(DTCodeType)functionTable.get(v.toLowerCase());
return t;
}
void insertGlobalVariable(String v,DTDataType t){
theGlobalScope.insertVariable(v,t);
}
void insertVariable(String v,DTDataType t){
getCurrentScope().insertVariable(v,t);
}
public DTDataType getVariable(String var){
DTDataType t=getCurrentScope().getVariable(var);
if(t==null){
t=theGlobalScope.getVariable(var);
}
return t;
}
public int getVariableDimension(String var){
int dim=0;
dim=getCurrentScope().getVariableDimension(var);
if(dim==0){
dim=theGlobalScope.getVariableDimension(var);
}
return dim;
}
public int getVariableType(String var){
DTDataType t=null;
t=getCurrentScope().getVariable(var);
if(t==null){
t=theGlobalScope.getVariable(var);
}
if(t!=null){
return t.getType();
} else {
return 0;
}
}
public boolean isArrayVariable(String s){
return (getVariableDimension(s) > 0);
}
public Scope getPrev(){
return getCurrentScope().getPrev();
}
public void pushScope(Scope scope){
theScopeStack.push(scope);
}
public Scope popScope(){
if( getCurrentScope() == theGlobalScope ){
return theGlobalScope;
} else {
return (Scope)theScopeStack.pop();
}
}
public Scope getCurrentScope(){
return ((Scope)theScopeStack.peek());
}
public Scope getGlobalScope(){
return theGlobalScope;
}
public void setProgramScope(Scope scope){
theProgramScope=scope;
while((Scope)theScopeStack.peek()!=theGlobalScope){
theScopeStack.pop();
}
theScopeStack.push(theProgramScope);
}
protected Scope getProgramScope(){
return theProgramScope;
}
public void setDimension(String s,DTDataType i1){
DTDataType v=getVariable(s);
v.setDimension(i1.getInteger());
}
public void initialize(){
setProgramScope(getProgramScope());
}
public void setDimension(String s,DTDataType i1,DTDataType i2){
DTDataType v=getVariable(s);
v.setDimension(i1.getInteger(),i2.getInteger());
}
public void setDimension(String s,DTDataType i1,DTDataType i2,DTDataType i3){
DTDataType v=getVariable(s);
v.setDimension(i1.getInteger(),i2.getInteger(),i3.getInteger());
}
public DTDataType getDTDataType(String s,DTDataType i1){
DTDataType t=getVariable(s);
return t.getDTDataType(i1);
}
public DTDataType getDTDataType(String s,DTDataType i1,DTDataType i2){
DTDataType t=getVariable(s);
return t.getDTDataType(i1,i2);
}
public DTDataType getDTDataType(String s,DTDataType i1,DTDataType i2,DTDataType i3){
DTDataType t=getVariable(s);
return t.getDTDataType(i1,i2,i3);
}
public DTDataType ensureVariable(String s,int t){
DTDataType v = getVariable(s);
if(v==null){
v=DTDataType.getOne(t,getCurrentScope());
insertVariable(s,v);
}
return v;
}
//public boolean isArrayVariable(String s){
// if(getCurrentScope().isArrayVariable(s){
// return true;
// } else {
// return theGlobalScope.isArrayVariable(s);
//}
//}
}
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