public Typing(Type[] inputs, List<Entry> stmts, int numSlots) {
this.stmts = new ArrayList<Entry>(stmts);
this.cache = new HashMap<String, Type[]>();
this.environments = new Type[stmts.size()][];
this.environments[0] = Arrays.copyOf(inputs, numSlots);
this.numSlots = numSlots;
}
private void determineTypesUpto(int end) {
Type[] environment = environments[0];
for (int i = position; i < end; ++i) {
Code code = stmts.get(i).code;
if (code instanceof Code.Label) {
Code.Label label = (Code.Label) code;
Type[] nEnv = cache.get(label.label);
environment = join(environment, nEnv);
} else if (code instanceof Code.AbstractAssignable) {
Code.AbstractAssignable c = (Code.AbstractAssignable) code;
environment = Arrays.copyOf(environment, environment.length);
environment[c.target] = c.assignedType();
} else if (code instanceof Code.Goto) {
Code.Goto gto = (Code.Goto) code;
cache.put(gto.target, environment);
environment = null;
} else if (code instanceof Code.If) {
Code.If gto = (Code.If) code;
cache.put(gto.target, environment);
} else if (code instanceof Code.IfIs) {
Code.IfIs gto = (Code.IfIs) code;
Type[] trueEnv = Arrays.copyOf(environment, environment.length);
trueEnv[gto.operand] = Type.intersect(trueEnv[gto.operand], gto.rightOperand);
cache.put(gto.target, trueEnv);
environment[gto.operand] =
Type.intersect(trueEnv[gto.operand], Type.Negation(gto.rightOperand));
} else if (code instanceof Code.Switch) {
Code.Switch sw = (Code.Switch) code;
for (Pair<Constant, String> c : sw.branches) {
cache.put(c.second(), environment);
}
cache.put(sw.defaultTarget, environment);
} else if (code instanceof Code.ForAll) {
// FIXME: what this need to do is update the type for the
// index variable, and then invalidate it afterwards.
throw new RuntimeException("need to implement for-all loop!");
} else if (code instanceof Code.Return || code instanceof Code.Throw) {
environment = null;
}
environments[i] = environment;
}
}