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;
}
}
private SemanticType propagate(
Expr.FunCall e,
HashMap<String, SemanticType> environment,
HashSet<String> generics,
WyalFile.Context context) {
SemanticType.Function fnType;
try {
Pair<NameID, SemanticType.Function> p = builder.resolveAsFunctionType(e.name, context);
fnType = p.second();
} catch (ResolveError re) {
syntaxError(
"cannot resolve as function or definition call", context.file().filename(), e, re);
return null;
}
SemanticType[] fn_generics = fnType.generics();
if (fn_generics.length != e.generics.length) {
// could resolve this with inference in the future.
syntaxError(
"incorrect number of generic arguments provided (got "
+ e.generics.length
+ ", required "
+ fn_generics.length
+ ")",
context.file().filename(),
e);
}
SemanticType argument = propagate(e.operand, environment, generics, context);
HashMap<String, SemanticType> binding = new HashMap<String, SemanticType>();
for (int i = 0; i != e.generics.length; ++i) {
SemanticType.Var gv = (SemanticType.Var) fn_generics[i];
binding.put(gv.name(), builder.convert(e.generics[i], generics, context));
}
fnType = (SemanticType.Function) fnType.substitute(binding);
checkIsSubtype(fnType.from(), argument, e.operand);
return fnType;
}