/**
* Set the local variable to the given value. If the value is null, then the corresponding
* variable will be removed. If there is a global variable of the same name, then an
* EvaluationException will be thrown.
*
* @param name name of the local variable
* @param terms terms used to dereference the variable, or null if the variable is to be used
* directly
* @param value value to use or null to remove the variable
* @throws EvaluationException if there is a global variable with the same name as the local
* variable
*/
public void setLocalVariable(String name, Term[] terms, Element value)
throws EvaluationException {
assert (name != null);
if (terms == null || terms.length == 0) {
// Revert back to the simple case that does not require
// dereferencing.
setLocalVariable(name, value);
} else {
// The more complicated case where we need to dereference the
// variable. (And also possibly create the parents.)
// Retrieve the value of the local variable.
Element var = getLocalVariable(name);
// If the value is a protected resource, then make a shallow copy
// and replace the value of the local variable.
if (var != null && var.isProtected()) {
var = var.writableCopy();
setLocalVariable(name, var);
}
// If the value does not exist, create a resource of the correct
// type and insert into variable table.
if (var == null || var instanceof Undef) {
Term term = terms[0];
if (term.isKey()) {
var = new HashResource();
} else {
var = new ListResource();
}
setLocalVariable(name, var);
}
// Recursively descend to set the value.
assert (var != null);
try {
var.rput(terms, 0, value);
} catch (InvalidTermException ite) {
throw new EvaluationException(ite.formatVariableMessage(name, terms));
}
}
}
