Assignment(String variableName,
    Expression value,
    int scope) 
{
                                    
        this.variableName = variableName;
        this.value = value;
        this.scope = scope;
}

Parameters:

variableName - the variable name to assign to.

value - the expression to assign.

scope - the scope of the assignment, one of NAMESPACE, LOCAL, or GLOBAL

  void accept(Environment env) throws TemplateException 
{
        TemplateModel tm = value.getAsTemplateModel(env);
        Environment.Namespace namespace = null;
        if (namespaceExp != null) {
            boolean oops = false;
            try {
                namespace = (Environment.Namespace) namespaceExp.getAsTemplateModel(env);
            } catch (ClassCastException cce) {
                oops = true;
            }
            if (oops || namespace==null) {
                throw new InvalidReferenceException(getStartLocation() + "\nInvalid reference to namespace: " + namespaceExp, env);
            }
        }
        if (tm == null) {
            if (env.isClassicCompatible()) {
                tm = TemplateScalarModel.EMPTY_STRING;
            }
            else {
                String msg = "Error " + getStartLocation()
                            +"\n" + value + " is undefined."
                            +"\nIt cannot be assigned to " + variableName;
                throw new InvalidReferenceException(msg, env);
            }
        }
        if (scope == LOCAL) {
            env.setLocalVariable(variableName, tm);
        }
        else {
            if (namespace == null) {
                if (scope == GLOBAL) {
                    namespace = env.getGlobalNamespace();
                }
                else if (scope == NAMESPACE) {
                    namespace = env.getCurrentNamespace();
                }
            }
            namespace.put(variableName, tm);
        }
}

 public String getCanonicalForm() 
{
        StringBuffer buf = new StringBuffer();
        if (!(parent instanceof AssignmentInstruction)) {
            if (scope == LOCAL) {
                buf.append("< #local ");
            }
            else if (scope ==GLOBAL) {
                buf.append("< #global ");
            }
            else {
                buf.append("< #assign ");
            }
        }
        buf.append (variableName);
        buf.append('=");
        buf.append(value.getCanonicalForm());
        if (!(parent instanceof AssignmentInstruction)) {
            if (namespaceExp != null) {
                buf.append(" in ");
                buf.append(namespaceExp.getCanonicalForm());
            }
            buf.append(" >");
        }
        return buf.toString();
}

 public String getDescription() 
{
        String s ="";
        if (!(parent instanceof AssignmentInstruction)) {
            s = "assignment: ";
            if (scope == LOCAL) {
                s = "local " + s;
            }
            else if (scope == GLOBAL) {
                s  = "global " + s;
            }
        }
        return s + variableName 
               + "=" 
               + value;
}

  void setNamespaceExp(Expression namespaceExp) 
{
        this.namespaceExp =  namespaceExp;
}