Example #1
0
 /** @see jaskell.compiler.JaskellVisitor#visit(Application) */
 public Object visit(Application a) {
   try {
     /* get type of function */
     Expression fun = a.getFunction();
     /* get type deduced from arguments */
     LinkedList l = new LinkedList();
     Iterator it = a.getArgs().iterator();
     while (it.hasNext()) {
       Expression e = (Expression) it.next();
       l.add((Type) e.visit(this));
     }
     Type vt = TypeFactory.freshBinding();
     Type ft = Types.fun(l, vt);
     log.finer("TypeChecker => In application " + a + ", type is " + ft);
     /* apply substitution on both types */
     ft = subst.substitute(ft);
     /* try to unify function type and constructed types */
     Type t = (Type) fun.visit(this);
     log.finer("In application, function " + fun + " :: " + t);
     t = subst.substitute(t);
     log.finer("In application, trying to unify function type " + t + " with body " + ft);
     /*
      * TODO : problem with unification of constrained types
      */
     TypeApplication uni = (TypeApplication) tu.unify(t, ft, typeVariablesMap);
     /* sets type of functional expression - this allows
      * polymorphic functions to receive several types
      * in the same code */
     // fun.setType(uni);
     /* apply arguments type to compute return type */
     log.finer("Done unify application :" + uni);
     it = PrimitiveType.functionIterator(uni);
     Iterator it2 = l.iterator();
     TypeApplication ut = uni;
     while (it2.hasNext()) {
       /* type of argument */
       Type at = (Type) it2.next();
       ut = (TypeApplication) it.next();
       /* try unification */
       tu.unify(((TypeApplication) ut.getDomain()).getRange(), at, new HashMap(typeVariablesMap));
     }
     ft = subst.substitute(ft);
     fun.setType(ft);
     log.finer("Setting type of functional element [" + fun + "] to :" + ft);
     a.setType(ut.getRange());
     return ut.getRange();
   } catch (TypeError te) {
     if (te.getLineCol() == null) te.setLineCol(a.getTag("source"));
     throw te;
   }
 }
Example #2
0
 /** @see jaskell.compiler.JaskellVisitor#visit(Abstraction) */
 public Object visit(Abstraction a) {
   try {
     Type t = a.getType();
     if (t != null) return subst.substitute(t);
     log.finest("Visiting abstraction : " + a);
     Expression body = a.getBody();
     /* duplicate bindings map to assign types to variables */
     pushContext(a.getBindings());
     /* create fresh type variables as type for each bound
      * variable */
     Iterator it = namesMap.values().iterator();
     LinkedList tl = new LinkedList();
     while (it.hasNext()) {
       LocalBinding name = (LocalBinding) it.next();
       Type vt = TypeFactory.freshBinding();
       name.setType(vt);
       tl.add(vt);
     }
     Type tv = TypeFactory.freshBinding();
     /* create type with all variables for function */
     Type ft = Types.fun(tl, tv);
     log.finer("In abstraction, setting type to " + ft);
     a.setType(ft);
     /* analyze body */
     Type bt = (Type) body.visit(this);
     /* unify return type of function with type of body */
     Type ret = tu.unify(PrimitiveType.getReturnType(ft), bt, typeVariablesMap);
     TyvarSubstitution tys = new TyvarSubstitution(typeVariablesMap);
     tys.visit(a);
     log.finer("Done abstraction, setting type from " + ft + " to " + a.getType());
     popContext();
     return a.getType();
   } catch (TypeError te) {
     if (te.getLineCol() == null) te.setLineCol(a.getTag("source"));
     throw te;
   }
 }