/**
* This method produces a new Abstraction which is the result of adding captured variables as new
* arguments and bind it in current ns. It returns the name of the bound funciton.
*
* @param a
* @param captured
* @return a String object denoting the name given to this function
* @throws SymbolException
*/
private String lift(Abstraction a, Set captured) throws SymbolException {
Abstraction abs = a;
if (!captured.isEmpty()) {
/* recreate abstraction adding captured variables */
abs = new Abstraction();
/* bind captured variables */
Iterator it = captured.iterator();
while (it.hasNext()) {
LocalBinding lb = (LocalBinding) it.next();
LocalBinding nlb = new LocalBinding(lb.getName());
abs.bind(nlb);
}
/* rebind old variables */
it = a.getBindings().values().iterator();
while (it.hasNext()) {
LocalBinding lb = (LocalBinding) it.next();
LocalBinding nlb = new LocalBinding(lb.getName());
abs.bind(nlb);
}
/* restore body */
abs.setBody(a.getBody());
}
/*
* bind new abstraction in ns if a is an anonymous abstraction - no class
* name - then it is renamed lambdaXXX and bound in namespace. Else, it is
* given a new name and a reference to this new name is stored in substMap.
*/
String newname = "lambda" + counter++;
ns.bind(newname, abs);
abs.setClassName(ns.getName() + "." + newname);
return newname;
}
/*
* (non-Javadoc)
*
* @see jaskell.compiler.JaskellVisitor#visit(jaskell.compiler.core.Module)
*/
public Object visit(Namespace a) {
/* set current namespace */
ns = a;
/*
* visit definitions We set an infinite loop to cope with modifications
* introduced by visiting sub expressions. When something is modified -
* through lift - we restart the whole process. TODO : change this to defer
* registering new bindings at end
*/
while (true) {
try {
Iterator it = a.getAllBindings().entrySet().iterator();
while (it.hasNext()) {
Map.Entry entry = (Map.Entry) it.next();
String functionName = (String) entry.getKey();
Expression def = (Expression) entry.getValue();
if (def instanceof Abstraction)
((Abstraction) def).setClassName(ns.getName() + "." + functionName);
log.finest("Analyzing lifting for " + functionName);
lift = false;
entry.setValue((Expression) def.visit(this));
}
break;
} catch (ConcurrentModificationException cmex) {
/* restart the process */
}
}
return a;
}
