/** @see jaskell.compiler.JaskellVisitor#visit(ConstructorPattern) */ public Object visit(ConstructorPattern a) { String cname = a.getConstructor().getName(); /* retrieve parameter types of constructor */ ConstructorDefinition ctor = (ConstructorDefinition) a.getConstructor().lookup(cname); if (ctor == null) throw new TypeError("Undefined constructor pattern " + a); /* type of data constructed by constructor */ TypeInstantiator ti = new TypeInstantiator(ctor.getDataType()); Type rtype = ti.instance(); Map map = ti.getMap(); TypeSubstitution ts = new TypeSubstitution(map); Iterator ittypes = ctor.getParameters().iterator(); /* retrieve type of patterns */ Iterator it = a.getSubPatterns(); while (it.hasNext()) { try { Pattern p = (Pattern) it.next(); Type actual = TypeFactory.freshBinding(); Type formal = ts.substitute((Type) ittypes.next()); /* unify both types */ p.setType(tu.unify(formal, actual, typeVariablesMap)); } catch (NoSuchElementException nex) { throw new TypeError("Wrong number of arguments to pattern " + a); } } a.setType(rtype); return a.getType(); }