/* ____ ____ ____ ____ ______ *\
** / __// __ \/ __// __ \/ ____/ SOcos COmpiles Scala **
** __\_ \/ /_/ / /__/ /_/ /\_ \ (c) 2002, LAMP/EPFL **
** /_____/\____/\___/\____/____/ **
**
** $Id$
\* */
//todo: T {} == T
package scalac.symtab;
import java.util.HashMap;
import scala.tools.util.Position;
import scalac.ApplicationError;
import scalac.atree.AConstant;
import scalac.util.*;
import scalac.Global;
public class Type implements Modifiers, Kinds, TypeTags, EntryTags {
public static boolean explainSwitch = false;
private static int indent = 0;
public case ErrorType; // not used after analysis
public case AnyType; // not used after analysis
public case NoType;
public case NoPrefix;
/** C.this.type
*/
public case ThisType(Symbol sym) {
assert sym.isClassType(): Debug.show(sym);
}
/** pre.sym.type
* sym represents a valueS
*/
public case SingleType(Type pre, Symbol sym) {
assert this instanceof ExtSingleType;
}
/** Type for a numeric or string constant.
*/
public case ConstantType(Type base, AConstant value);
/** pre.sym[args]
* sym represents a type
* for example: scala.List[java.lang.String] is coded as
*
* TypeRef(
* SingleType(ThisType(definitions.ROOT_CLASS), definitions.SCALA),
* <List>,
* new Type[]{
* TypeRef(
* SingleType(
* SingleType(ThisType(definitions.ROOT_CLASS), definitions.JAVA),
* definitions.LANG),
* definitions.STRING,
* new Type[]{})}).
*
*/
public case TypeRef(Type pre, Symbol sym, Type[] args) {
assert this instanceof ExtTypeRef: this;
}
/** parts_1 with ... with parts_n { members }
*/
public case CompoundType(Type[] parts, Scope members) {
assert this instanceof ExtCompoundType;
}
/** synthetic type of a method def ...(vparams): result = ...
*/
public case MethodType(Symbol[] vparams, Type result) {
for (int i = 0; i < vparams.length; i++)
assert vparams[i].isParameter() && vparams[i].isTerm(): this;
}
/** synthetic type of a method def ...[tparams]result
* For instance, given def f[a](x: a): a
* f has type PolyType(new Symbol[]{<a>},
* MethodType(new Symbol[]{<x>}, <a>.type()))
*
* if tparams is empty, this is the type of a parameterless method
* def ... =
* For instance, given def f = 1
* f has type PolyType(new Symbol[]{}, <scala.Int>.type())
*/
public case PolyType(Symbol[] tparams, Type result) {
for (int i = 0; i < tparams.length; i++)
assert tparams[i].isParameter()&&tparams[i].isAbstractType(): this;
}
/** synthetic type of an overloaded value whose alternatives are
* alts_1, ..., alts_n, with respective types alttypes_1, ..., alttypes_n
*
* For instance, if there are two definitions of `f'
* def f: int
* def f: String
* then there are three symbols:
* ``f1'' corresponding to def f: int
* ``f2'' corresponding to def f: String
* ``f3'' corresponding to both
* f3 has type
* OverloadedType(
* new Symbol[]{<f1>, <f2>},
* new Type[]{PolyType(new Symbol[]{}, <int>),
* PolyType(new Symbol[]{}, <String>),
*
*/
public case OverloadedType(Symbol[] alts, Type[] alttypes);
/** Hidden case to implement delayed evaluation of types.
* No need to pattern match on this type; it will never come up.
*/
public case LazyType();
/** Hidden case to implement local type inference.
* Later phases do not need to match on this type.
*/
public case TypeVar(Type origin, Constraint constr);
/** Hidden cases to implement type erasure.
* Earlier phases do not need to match on these types.
*/
public case UnboxedType(int tag);
public case UnboxedArrayType(Type elemtp);
/** Force evaluation of a lazy type. No cycle
* check is needed; since this is done in Symbol.
* @see Symbol.info().
*/
public void complete(Symbol p) {}
// Creators ---------------------------------------------------------------------
/** An empty Type array */
public static final Type[] EMPTY_ARRAY = new Type[0];
public static SingleType singleType(Type pre, Symbol sym) {
assert sym.isTerm() && !sym.isNone(): pre + " -- " + Debug.show(sym);
rebind:
{
Symbol owner = sym.owner();
if (!owner.isClass()) break rebind;
if (owner == pre.symbol()) break rebind;
// !!! add if (owner is sealed/final) break rebind ?
// !!! add if (owner is module class) break rebind ?
if (sym.isFinal() || sym.isPrivate()) break rebind;
Symbol rebind = pre.lookupNonPrivate(sym.name);
if (rebind.isNone()) break rebind;
if (rebind.isLocked()) throw new Type.Error(
"illegal cyclic reference involving " + rebind);
sym = rebind.rebindSym();
}
if (pre.isStable() || pre.isError()) {
return new ExtSingleType(pre, sym);
} else {
throw new Type.Malformed(pre, sym.nameString() + ".type");
}
}
public static Type constantType(AConstant value) {
return Global.instance.definitions.atyper.type(value);
}
public static Type singleTypeMethod(Type pre, Symbol sym) {
Global global = Global.instance;
if (global.currentPhase.id <= global.PHASE.UNCURRY.id())
return singleType(pre, sym);
else if (global.currentPhase.id <= global.PHASE.ERASURE.id())
return sym.type().singleTypeMethod0(pre, sym);
else
return pre.memberType(sym);
}
private Type singleTypeMethod0(Type pre, Symbol sym) {
switch (this) {
case PolyType(Symbol[] args, Type result):
return PolyType(args, result.singleTypeMethod0(pre, sym));
case MethodType(Symbol[] args, Type result):
return MethodType(args, result.singleTypeMethod0(pre, sym));
default:
return singleType(pre, sym);
}
}
public static Type appliedType(Type tycon, Type[] args) {
switch (tycon) {
case TypeRef(Type pre, Symbol sym, Type[] args1):
if (args == args1) return tycon;
else return Type.typeRef(pre, sym, args);
default:
throw Debug.abort("illegal case", tycon);
}
}
public static Type typeRef(Type pre, Symbol sym, Type[] args) {
if (!pre.isLegalPrefix() && !pre.isError())
throw new Type.Malformed(pre, sym.nameString());
rebind:
if (sym.isAbstractType()) {
Symbol owner = sym.owner();
if (!owner.isClass()) break rebind;
if (owner == pre.symbol()) break rebind;
// !!! add if (owner is sealed/final) break rebind ?
// !!! add if (owner is module class) break rebind ?
if (sym.isFinal() || sym.isPrivate()) break rebind;
Symbol rebind = pre.lookupNonPrivate(sym.name);
if (rebind.isNone()) break rebind;
if (rebind.isLocked()) throw new Type.Error(
"illegal cyclic reference involving " + rebind);
sym = rebind.rebindSym();
}
if (sym.isTypeAlias()) {
Symbol[] params = sym.typeParams();
if (args.length == params.length)
return pre.memberInfo(sym).subst(params, args);
assert args.length == 0 || args.length == params.length:
Debug.show(pre, " - ", sym, " - ", args, " - ", params);
}
assert isLegalTypeRef(pre, sym, args):
Debug.show(pre, " - ", sym, " - ", args, " - ", sym.typeParams());
return new ExtTypeRef(pre, sym, args);
}
private static boolean isLegalTypeRef(Type pre, Symbol sym, Type[] args) {
if (!pre.isLegalPrefix() && !pre.isError()) return false;
if (!sym.isType() && !sym.isError()) return false;
// !!! return args.length == 0 || args.length == sym.typeParams().length;
return true;
}
public static Type newTypeRefUnsafe(Type pre, Symbol sym, Type[] args) {
return new ExtTypeRef(pre, sym, args);
}
public static CompoundType compoundType(Type[] parts, Scope members,
Symbol clazz) {
return new ExtCompoundType(parts, members, clazz);
}
public static CompoundType compoundTypeWithOwner(Symbol owner, Type[] parts, Scope members) {
return new ExtCompoundType(owner, parts, members);
}
static class ExtSingleType extends SingleType {
Type tp = null;
int definedId = -1;
ExtSingleType(Type pre, Symbol sym) {
super(pre, sym);
}
public Type singleDeref() {
if (definedId != Global.instance.currentPhase.id) {
definedId = Global.instance.currentPhase.id;
tp = pre.memberType(sym).resultType();
}
return tp;
}
}
static class ExtTypeRef extends TypeRef {
ExtTypeRef(Type pre, Symbol sym, Type[] args) {
super(pre, sym, args);
}
}
private static final class ExtCompoundType extends CompoundType {
private final Symbol clasz;
public ExtCompoundType(Symbol owner, Type[] parts, Scope members) {
super(parts, members);
this.clasz = owner.newCompoundClass(this);
assert !owner.isPackageClass() : ArrayApply.toString(parts);
}
public ExtCompoundType(Type[] parts, Scope members, Symbol clasz) {
super(parts, members);
this.clasz = clasz;
}
public Symbol symbol() {
return clasz;
}
}
// Access methods ---------------------------------------------------------------
/** If this is a thistype, named type, applied type, singleton type, or compound type,
* its symbol, otherwise Symbol.NONE.
*/
public Symbol symbol() {
switch (this) {
case ThisType(Symbol sym):
return sym;
case TypeRef(_, Symbol sym, _):
return sym;
case SingleType(_, Symbol sym):
return sym;
case ConstantType(Type base, _):
return base.symbol();
case TypeVar(Type origin, _):
return origin.symbol();
case CompoundType(_, _):
// overridden in ExtCompoundType
throw new ApplicationError();
default:
return Symbol.NONE;
}
}
public static Symbol[] symbol(Type[] tps) {
Symbol[] syms = new Symbol[tps.length];
for (int i = 0; i < syms.length; i++)
syms[i] = tps[i].symbol();
return syms;
}
/** If this is a reference to a type constructor, add its
* type parameters as arguments
*/
public Type withDefaultArgs() {
switch (this) {
case TypeRef(Type pre, Symbol sym, Type[] args):
if (args.length == 0 && sym.typeParams().length != 0)
return Type.typeRef(pre, sym, Symbol.type(sym.typeParams()));
}
return this;
}
/** The upper bound of this type. Returns always a TypeRef whose
* symbol is a class.
*/
public Type bound() {
switch (unalias()) {
case TypeRef(Type pre, Symbol sym, _):
if (sym.kind == TYPE) return pre.memberInfo(sym).bound();
assert sym.isClass() : Debug.show(sym) + " -- " + this;
return this;
case ThisType(_):
case SingleType(_, _):
case ConstantType(_, _):
return singleDeref().bound();
case TypeVar(Type origin, Constraint constr):
if (constr.inst != NoType) return constr.inst.bound();
else return this;
default:
throw Debug.abort("illegal case", this);
}
}
/** If this type is a thistype or singleton type, its type,
* otherwise the type itself.
*/
public Type singleDeref() {
switch (this) {
case ThisType(Symbol sym):
return sym.typeOfThis();
case SingleType(Type pre, Symbol sym):
// overridden in ExtSingleType
throw new ApplicationError();
case ConstantType(Type base, _):
return base;
case TypeVar(Type origin, Constraint constr):
if (constr.inst != NoType) return constr.inst.singleDeref();
else return this;
default:
return this;
}
}
/** If this type is a thistype or singleton type, its underlying object type,
* otherwise the type itself.
*/
public Type widen() {
Type tp = singleDeref();
switch (tp) {
case ThisType(_):
case SingleType(_, _):
case ConstantType(_, _):
return tp.widen();
default:
return tp;
}
}
private static Map widenMap = new Map() {
public Type apply(Type t) {
return t.widen();
}
};
public static Type[] widen(Type[] tps) {
return widenMap.map(tps);
}
/** The thistype or singleton type corresponding to values of this type.
*/
public Type narrow() {
switch (unalias()) {
case TypeRef(Type pre, Symbol sym, Type[] args):
if (sym.kind == CLASS) return sym.thisType();
else return ThisType(sym);
case CompoundType(_, _):
return symbol().thisType();
default:
return this;
}
}
/** If this type is a constant type, its underlying basetype;
* otherwise the type itself
*/
public Type deconst() {
switch (this) {
case ConstantType(Type base, _):
return base;
default:
return this;
}
}
/** If this type is a parameterless method, its underlying resulttype;
* otherwise the type itself
*/
public Type derefDef() {
switch (this) {
case PolyType(Symbol[] tparams, Type restp):
if (tparams.length == 0) return restp;
}
return this;
}
/** The lower approximation of this type (which must be a typeref)
*/
public Type loBound() {
switch (unalias()) {
case TypeRef(Type pre, Symbol sym, Type[] args):
Type lb = Global.instance.definitions.ALL_TYPE();
if (sym.kind == TYPE) {
lb = pre.memberLoBound(sym);
}
if (lb.symbol() == Global.instance.definitions.ALL_CLASS &&
this.symbol() != Global.instance.definitions.ALL_CLASS &&
this.isSubType(Global.instance.definitions.ANYREF_TYPE())) {
lb = Global.instance.definitions.ALLREF_TYPE();
}
return lb;
default:
throw new ApplicationError();
}
}
/** If this is a this-type, named-type, applied type or single-type, its prefix,
* otherwise NoType.
*/
public Type prefix() {
switch (this) {
case ThisType(Symbol sym): return sym.owner().thisType();
case TypeRef(Type pre, _, _): return pre;
case SingleType(Type pre, _): return pre;
case TypeVar(Type origin, Constraint constr):
if (constr.inst != NoType) return constr.inst.prefix();
else return NoType;
default: return NoType;
}
}
/** Get all type arguments of this type.
*/
public Type[] typeArgs() {
switch (unalias()) {
case TypeRef(_, _, Type[] args):
return args;
default:
return Type.EMPTY_ARRAY;
}
}
/** Get type of `this' symbol corresponding to this type, extend
* homomorphically to function types and poly types.
*/
public Type instanceType() {
switch (unalias()) {
case TypeRef(Type pre, Symbol sym, Type[] args):
if (sym != sym.thisSym())
return sym.typeOfThis()
.asSeenFrom(pre, sym.owner())
.subst(sym.typeParams(), args);
break;
case MethodType(Symbol[] params, Type restp):
Type restp1 = restp.instanceType();
if (restp1 != restp)
return MethodType(params, restp1);
break;
case PolyType(Symbol[] tparams, Type restp):
Type restp1 = restp.instanceType();
if (restp1 != restp)
return PolyType(tparams, restp1);
break;
}
return this;
}
/** Remove all aliases
*/
public Type unalias() {
Type result = unalias(0);//debug
//if (this != result) System.out.println(this + " ==> " + result);//DEBUG
return result;
}
private Type unalias(int n) {
if (n == 100)
throw new Type.Error("alias chain too long (recursive type alias?): " + this);
switch (this) {
case TypeVar(Type origin, Constraint constr):
if (constr.inst != NoType) return constr.inst.unalias(n + 1);
else return this;
}
return this;
}
/** The (prefix/argument-adapted) parents of this type.
*/
public Type[] parents() {
switch (unalias()) {
case ThisType(_):
case SingleType(_, _):
case ConstantType(_, _):
return singleDeref().parents();
case TypeRef(Type pre, Symbol sym, Type[] args):
if (sym.kind == CLASS) {
assert sym.typeParams().length == args.length : sym + " " + ArrayApply.toString(args) + " " + sym.primaryConstructor().info();//debug
return subst(asSeenFrom(sym.info().parents(), pre, sym.owner()),
sym.typeParams(), args);
} else {
return new Type[]{sym.info().asSeenFrom(pre, sym.owner())};
}
case CompoundType(Type[] parts, _):
return parts;
default:
return Type.EMPTY_ARRAY;
}
}
/** Get type parameters of method type (a PolyType or MethodType)
* or EMPTY_ARRAY if method type is not polymorphic.
*/
public Symbol[] typeParams() {
switch (this) {
case PolyType(Symbol[] tparams, _):
return tparams;
case MethodType(Symbol[] vparams, _):
return Symbol.EMPTY_ARRAY;
case TypeRef(_, Symbol sym, Type[] args):
if (args.length == 0) return sym.typeParams();
else return Symbol.EMPTY_ARRAY;
default:
return Symbol.EMPTY_ARRAY;
}
}
/** Get value parameters of method type (a PolyType or MethodType)
* or EMPTY_ARRAY if method type has no value parameter section.
*/
public Symbol[] valueParams() {
return valueParams(false);
}
private Symbol[] valueParams(boolean ok) {
switch (this) {
case PolyType(_, Type result):
return result.valueParams(true);
case MethodType(Symbol[] vparams, _):
return vparams;
default:
if (ok) return Symbol.EMPTY_ARRAY;
throw Debug.abort("illegal case", this);
}
}
/** If this type is a (possibly polymorphic) method type, its result type
* after applying all method argument sections,
* otherwise the type itself.
*/
public Type resultType() {
switch (this) {
case PolyType(_, Type tpe):
return tpe.resultType();
case MethodType(_, Type tpe):
return tpe.resultType();
default:
return this;
}
}
/** The number of value parameter sections of this type.
*/
public int paramSectionCount() {
switch (this) {
case PolyType(_, Type restpe):
return restpe.paramSectionCount();
case MethodType(_, Type restpe):
return restpe.paramSectionCount() + 1;
default: return 0;
}
}
/** The first parameter section of this type.
*/
public Symbol[] firstParams() {
switch (this) {
case PolyType(_, Type restpe):
return restpe.firstParams();
case MethodType(Symbol[] params, _):
return params;
default: return Symbol.EMPTY_ARRAY;
}
}
/** If this type is overloaded, its alternative types,
* otherwise an array consisting of this type itself.
*/
public Type[] alternativeTypes() {
switch (this) {
case OverloadedType(_, Type[] alttypes):
return alttypes;
default:
return new Type[]{this};
}
}
/** If this type is overloaded, its alternative symbols,
* otherwise an empty array.
*/
public Symbol[] alternativeSymbols() {
switch (this) {
case OverloadedType(Symbol[] alts, _):
return alts;
default:
return Symbol.EMPTY_ARRAY;
}
}
// Tests --------------------------------------------------------------------
/** Is this type a an error type?
*/
public boolean isError() {
switch (this) {
case ErrorType:
return true;
case ThisType(Symbol clasz):
return clasz.isError();
case SingleType(_, Symbol symbol):
return symbol.isError();
case TypeRef(_, Symbol symbol, _):
return symbol.isError();
case CompoundType(Type[] parts, Scope members):
return symbol().isError();
default:
return false;
}
}
/** Is this type a this type or singleton type?
*/
public boolean isStable() {
switch (unalias()) {
case NoPrefix:
case ThisType(_):
case SingleType(_, _):
case ConstantType(_, _):
return true;
case TypeRef(_, Symbol sym, _):
if (sym.isParameter() && sym.isSynthetic() && sym.hasStableFlag()) return true;
return false;
default:
return false;
}
}
/** Is this type a legal prefix?
*/
public boolean isLegalPrefix() {
switch (unalias()) {
case NoPrefix:
case ThisType(_):
case SingleType(_, _):
return true;
case TypeRef(_, Symbol sym, _):
if (sym.isParameter() && sym.isSynthetic()) return true;
return sym.kind == CLASS &&
((sym.flags & JAVA) != 0 ||
(sym.flags & (TRAIT | ABSTRACT)) == 0);
default:
return false;
}
}
/** Is this type a reference to an object type?
* todo: replace by this.isSubType(global.definitions.ANY_TYPE())?
*/
public boolean isObjectType() {
switch (unalias()) {
case ThisType(_):
case SingleType(_, _):
case ConstantType(_, _):
case CompoundType(_, _):
case TypeRef(_, _, _):
return true;
default:
return false;
}
}
/** Is this type of the form scala.FunctionN[T_1, ..., T_n, +T] or
* scala.AnyRef with scala.FunctionN[T_1, ..., T_n, +T] or
* java.lang.Object with scala.FunctionN[T_1, ..., T_n, +T]?
*/
public boolean isFunctionType() {
switch (this) {
case TypeRef(Type pre, Symbol sym, Type[] args):
Definitions definitions = Global.instance.definitions;
return args.length > 0
&& args.length <= definitions.FUNCTION_COUNT
&& sym == definitions.FUNCTION_CLASS[args.length - 1];
case CompoundType(Type[] parents, Scope members):
Definitions definitions = Global.instance.definitions;
return members.isEmpty() &&
parents.length == 2 &&
(parents[0].symbol() == definitions.OBJECT_CLASS ||
parents[0].symbol() == definitions.ANYREF_CLASS) &&
parents[1].isFunctionType();
}
return false;
}
/** Is this a polymorphic method type?
*/
public boolean isPolymorphic() {
return typeParams().length > 0;
}
/** Is this a parameterized or polymorphic method type?
*/
public boolean isParameterized() {
switch (this) {
case MethodType(_, _): return true;
default: return isPolymorphic();
}
}
// Members and Lookup -------------------------------------------------------
/** Get the scope containing the local members of this type.
* Symbols in this scope are not prefix-adapted!
*/
public Scope members() {
switch (this) {
case ErrorType:
return new Scope();
case TypeRef(_, Symbol sym, _):
return sym.info().members();
case SingleType(_, _):
case ConstantType(_, _):
return singleDeref().members();
case CompoundType(Type[] basetypes, Scope members):
return members;
default:
return Scope.EMPTY;
}
}
/** Lookup symbol with given name among all local and inherited members
* of this type; return Symbol.NONE if not found.
*/
public Symbol lookup(Name name) {
switch (this) {
case ErrorType:
return new ErrorScope(Symbol.NONE).lookup(name);
case ThisType(_):
case SingleType(_, _):
case ConstantType(_, _):
return singleDeref().lookup(name);
case TypeRef(_, Symbol sym, _):
return sym.info().lookup(name);
case CompoundType(Type[] parts, Scope members):
Symbol sym = members.lookup(name);
if (sym.kind != NONE) return sym;
else return lookupNonPrivate(name);
default:
return Symbol.NONE;
}
}
/** Lookup non-private symbol with given name among all local and
* inherited members of this type; return Symbol.NONE if not found.
*/
public Symbol lookupNonPrivate(Name name) {
switch (this) {
case ErrorType:
return new ErrorScope(Symbol.NONE).lookup(name);
case ThisType(_):
case SingleType(_, _):
case ConstantType(_, _):
return singleDeref().lookupNonPrivate(name);
case TypeRef(_, Symbol sym, _):
return sym.info().lookupNonPrivate(name);
case CompoundType(Type[] parts, Scope members):
Symbol sym = members.lookup(name);
if (sym.kind != NONE && (sym.flags & PRIVATE) == 0)
return sym;
// search base types in reverse; non-abstract members
// take precedence over abstract ones.
int i = parts.length;
sym = Symbol.NONE;
while (i > 0) {
i--;
Symbol sym1 = parts[i].lookupNonPrivate(name);
if (sym1.kind != NONE &&
(sym1.flags & PRIVATE) == 0 &&
(sym.kind == NONE
||
(sym.flags & DEFERRED) != 0 &&
(sym1.flags & DEFERRED) == 0
||
(sym.flags & DEFERRED) == (sym1.flags & DEFERRED) &&
sym1.owner().isSubClass(sym.owner())))
sym = sym1;
}
return sym;
default:
return Symbol.NONE;
}
}
/**
* Looks up in the current type a symbol with the same name as the
* given symbol and whose type (as seen from the given prefix) is
* in the given relation to the type (as seen from the given
* prefix) of the given symbol. If no such symbol is found,
* returns NONE. Note that in some cases, the returned symbol may
* be equal to the given one. The main purpose of this method is
* look up overridden and overriding symbols.
*/
public Symbol lookup(Symbol sym, Type pre, Relation relation) {
assert !sym.isOverloaded(): Debug.show(sym);
if (sym.isPrivate() || sym.isInitializer())
return symbol().isSubClass(sym.owner()) ? sym : Symbol.NONE;
Type symtype = pre.memberType(sym).derefDef();
Symbol[] classes = classes();
Symbol deferred = null;
for (int i = 0; i < classes.length; i++) {
if (deferred != null && deferred.isSubClass(classes[i])) continue;
Symbol sym1 = classes[i].members().lookup(sym.name);
switch (sym1.type()) {
case NoType:
case ErrorType:
continue;
case OverloadedType(Symbol[] alts, _):
for (int j = 0; j < alts.length; j++)
if (areRelated(sym, symtype, relation, pre,alts[j],false)){
if (!alts[j].isDeferred()) return alts[j];
if (deferred == null) deferred = alts[j];
}
continue;
default:
if (areRelated(sym, symtype, relation, pre, sym1, true)) {
if (!sym1.isDeferred()) return sym1;
if (deferred == null) deferred = sym1;
}
continue;
}
}
return deferred == null ? Symbol.NONE : deferred;
}
//where
private static boolean areRelated(
Symbol sym, Type symtype, Relation relation, Type pre, Symbol sym1,
boolean warn)
{
if (sym == sym1) return true;
if (sym1.isPrivate() || sym1.isInitializer()) return false;
// System.out.println("Is 'sym1' " + relation + " 'sym' in 'pre' ?"
// + "\n sym : " + Debug.show(sym)
// + "\n sym1 : " + Debug.show(sym1)
// + "\n sym .type: " + sym.type()
// + "\n sym1.type: " + sym1.type()
// + "\n pre : " + pre
// );//DEBUG
Type sym1type = pre.memberType(sym1).derefDef();
if (sym1.isJava()) symtype = symtype.objParamToAny();
if (sym1type.compareTo(symtype, relation)) return true;
if (warn && Global.instance.debug) System.out.println(
"'sym1' is not " + relation + " 'sym' in 'pre'"
+ "\n sym : " + Debug.show(sym)
+ "\n sym1 : " + Debug.show(sym1)
+ "\n sym .type: " + sym.type()
+ "\n sym1.type: " + sym1.type()
+ "\n pre : " + pre
+ "\nsince 'sym1type' " + relation.toString(true) + " 'symtype'"
+ "\n symtype : " + symtype
+ "\n sym1type : " + sym1type
);//DEBUG
return false;
}
private Symbol[] classes() {
switch (this) {
case ThisType(_):
case SingleType(_, _):
case ConstantType(_, _):
return singleDeref().classes();
case TypeRef(_, Symbol sym, _):
return sym.info().classes();
case CompoundType(Type[] parts, Scope members):
return symbol(symbol().closure());
default:
return Symbol.EMPTY_ARRAY;
}
}
static private Map objToAnyMap = new Map() {
public Type apply(Type t) {
if (t.symbol() == Global.instance.definitions.OBJECT_CLASS)
return Global.instance.definitions.ANY_TYPE();
else return t;
}
};
private Type objParamToAny() {
switch (this) {
case MethodType(Symbol[] params, Type restp):
Symbol[] params1 = objToAnyMap.map(params);
if (params1 == params) return this;
else return MethodType(params1, restp);
default:
return this;
}
}
// Set Owner ------------------------------------------------------------------
public Type setOwner(Symbol owner) {
switch (this) {
case PolyType(Symbol[] tparams, Type restpe):
Type restpe1 = restpe.setOwner(owner);
if (restpe1 == restpe) return this;
else return Type.PolyType(tparams, restpe1);
case MethodType(Symbol[] params, Type restpe):
Symbol[] params1 = params;
if (params.length > 0 &&
params[0].owner() != owner && params[0].owner() != Symbol.NONE) {
params1 = new Symbol[params.length];
for (int i = 0; i < params.length; i++)
params1[i] = params[i].cloneSymbol();
}
for (int i = 0; i < params.length; i++)
params1[i].setOwner(owner);
Type restpe1 = restpe.setOwner(owner);
if (params1 == params && restpe1 == restpe) return this;
else return Type.MethodType(params1, restpe1);
default:
return this;
}
}
// Maps --------------------------------------------------------------------------
/** The type of type-to-type functions.
*/
public abstract static class Map {
public abstract Type apply(Type t);
/**
* This method assumes that all symbols in MethodTypes and
* PolyTypes have already been cloned.
*/
public Type applyParams(Type type) {
switch (type) {
case MethodType(Symbol[] vparams, Type result):
map(vparams, true);
Type result1 = applyParams(result);
return result == result1 ? type : MethodType(vparams, result1);
case PolyType(Symbol[] tparams, Type result):
map(tparams, true);
Type result1 = applyParams(result);
return result == result1 ? type : PolyType(tparams, result1);
default:
return apply(type);
}
}
/** Apply map to all top-level components of this type.
*/
public Type map(Type tp) {
switch (tp) {
case ErrorType:
case AnyType:
case NoType:
case NoPrefix:
case UnboxedType(_):
case TypeVar(_, _):
case ThisType(_):
return tp;
case TypeRef(Type pre, Symbol sym, Type[] args):
Type pre1 = apply(pre);
Type[] args1 = map(args);
if (pre1 == pre && args1 == args) return tp;
else return typeRef(pre1, sym, args1);
case SingleType(Type pre, Symbol sym):
Type pre1 = apply(pre);
if (pre1 == pre) return tp;
else return singleType(pre1, sym);
case ConstantType(Type base, AConstant value):
Type base1 = apply(base);
if (base1 == base) return tp;
else return new ConstantType(base1, value);
case CompoundType(Type[] parts, Scope members):
Type[] parts1 = map(parts);
Scope members1 = map(members);
if (parts1 == parts && members1 == members) {
return tp;
} else if (members1 == members && !tp.symbol().isCompoundSym()) {
return compoundType(parts1, members, tp.symbol());
} else {
Scope members2 = new Scope();
//Type tp1 = compoundType(parts1, members2);
Type tp1 = (tp.symbol().isCompoundSym()) ? compoundTypeWithOwner(tp.symbol().owner(), parts1, members2)
: compoundType(parts1, members2, tp.symbol());
Symbol[] syms1 = members1.elements();
Symbol[] syms2 = new Symbol[syms1.length];
for (int i = 0; i < syms2.length; i++) {
syms2[i] = syms1[i].cloneSymbol(tp1.symbol());
}
for (int i = 0; i < syms2.length; i++) {
syms2[i].setInfo(syms1[i].info().subst(syms1, syms2));
if (syms2[i].kind == TYPE) {
syms2[i].setLoBound(syms1[i].loBound().subst(syms1, syms2));
syms2[i].setVuBound(syms1[i].vuBound().subst(syms1, syms2));
}
}
for (int i = 0; i < syms2.length; i++) {
members2.enter(syms2[i]);
}
return tp1;
}
case MethodType(Symbol[] vparams, Type result):
Symbol[] vparams1 = map(vparams);
Type result1 = apply(result);
if (vparams1 == vparams && result1 == result) return tp;
else return MethodType(vparams1, result1);
case PolyType(Symbol[] tparams, Type result):
Symbol[] tparams1 = map(tparams);
Type result1 = apply(result);
if (tparams1 != tparams) result1 = result1.subst(tparams, tparams1);
if (tparams1 == tparams && result1 == result) return tp;
else return PolyType(tparams1, result1);
case OverloadedType(Symbol[] alts, Type[] alttypes):
Type[] alttypes1 = map(alttypes);
if (alttypes1 == alttypes) return tp;
else return OverloadedType(alts, alttypes1);
case UnboxedArrayType(Type elemtp):
Type elemtp1 = apply(elemtp);
if (elemtp1 == elemtp) return tp;
else return UnboxedArrayType(elemtp1);
default:
throw new ApplicationError(tp + " " + tp.symbol());
}
}
public final Symbol map(Symbol sym) {
return map(sym, false);
}
public Symbol map(Symbol sym, boolean dontClone) {
Type tp = sym.info();
Type tp1 = apply(tp);
if (tp != tp1) {
if (!dontClone) sym = sym.cloneSymbol();
sym.setInfo(tp1);
dontClone = true;
}
if (sym.kind == TYPE) {
Type lb = sym.loBound();
Type lb1 = apply(lb);
if (lb != lb1) {
if (!dontClone) sym = sym.cloneSymbol();
sym.setLoBound(lb1);
}
Type vb = sym.vuBound();
Type vb1 = apply(vb);
if (vb != vb1) {
if (!dontClone) sym = sym.cloneSymbol();
sym.setVuBound(vb1);
}
}
return sym;
}
public Type[] map(Type[] tps) {
Type[] tps1 = tps;
for (int i = 0; i < tps.length; i++) {
Type tp = tps[i];
Type tp1 = apply(tp);
if (tp1 != tp && tps1 == tps) {
tps1 = new Type[tps.length];
System.arraycopy(tps, 0, tps1, 0, i);
}
tps1[i] = tp1;
}
return tps1;
}
/** Apply map to all elements of this array of symbols,
* preserving recursive references to symbols in the array.
*/
public final Symbol[] map(Symbol[] syms) {
return map(syms, false);
}
public Symbol[] map(Symbol[] syms, boolean dontClone) {
Symbol[] syms1 = syms;
for (int i = 0; i < syms.length; i++) {
Symbol sym = syms[i];
Symbol sym1 = map(sym, dontClone);
if (sym != sym1 && syms1 == syms) {
syms1 = new Symbol[syms.length];
System.arraycopy(syms, 0, syms1, 0, i);
}
syms1[i] = sym1;
}
if (syms1 != syms) {
for (int i = 0; i < syms1.length; i++) {
if (syms1[i] == syms[i])
syms1[i] = syms[i].cloneSymbol();
}
new SubstSymMap(syms, syms1).map(syms1, true);
}
return syms1;
}
/** Apply map to all elements of this array of this scope.
*/
public Scope map(Scope s) {
Symbol[] members = s.elements();
Symbol[] members1 = map(members);
if (members == members1) return s;
else return new Scope(members1);
}
}
public abstract static class MapOnlyTypes extends Map {
public Symbol map(Symbol sym, boolean dontClone) { return sym; }
public Symbol[] map(Symbol[] syms, boolean dontClone) { return syms; }
public Scope map(Scope s) { return s; }
}
public static final Map IdMap = new Map() {
public Type apply(Type tp) { return tp; }
public Type applyParams(Type tp) { return tp; }
public Type map(Type tp) { return tp; }
public Symbol map(Symbol sym, boolean dontClone) { return sym; }
public Type[] map(Type[] tps) { return tps; }
public Symbol[] map(Symbol[] syms, boolean dontClone) { return syms; }
public Scope map(Scope scope) { return scope; }
};
// baseType and asSeenFrom --------------------------------------------------------
/** Return the base type of this type whose symbol is `clazz', or NoType, if
* such a type does not exist.
*/
public Type baseType(Symbol clazz) {
//System.out.println(this + ".baseType(" + clazz + ")");//DEBUG
switch (this) {
case ErrorType:
return ErrorType;
case ThisType(_):
case SingleType(_, _):
case ConstantType(_, _):
return singleDeref().baseType(clazz);
case TypeRef(Type pre, Symbol sym, Type[] args):
if (sym == clazz)
return this;
else if (sym.kind == TYPE)
return sym.info()
.asSeenFrom(pre, sym.owner()).baseType(clazz);
else if (sym.kind == ALIAS)
return Type.NoType;
else if (clazz.isCompoundSym())
return NoType;
else {
return sym.baseType(clazz)
.asSeenFrom(pre, sym.owner())
.subst(sym.typeParams(), args);
}
case CompoundType(Type[] parts, _):
for (int i = parts.length - 1; i >= 0; i--) {
Type result = parts[i].baseType(clazz);
if (result != NoType) return result;
}
break;
case UnboxedArrayType(_):
if (clazz == Global.instance.definitions.ANY_CLASS ||
clazz == Global.instance.definitions.ANYREF_CLASS)
return clazz.type();
}
return NoType;
}
/** A map to implement `asSeenFrom'.
*/
static class AsSeenFromMap extends Map {
private final Type pre;
private final Symbol clazz;
AsSeenFromMap(Type pre, Symbol clazz) {
this.pre = pre;
this.clazz = clazz;
}
public Type apply(Type type) {
//System.out.println(type + " as seen from " + pre + "," + clazz);//DEBUG
if (pre == NoType || clazz.kind != CLASS) return type;
switch (type) {
case ThisType(Symbol sym):
return type.toPrefix(sym, pre, clazz);
case TypeRef(Type prefix, Symbol sym, Type[] args):
if (sym.owner().isPrimaryConstructor()) {
assert sym.kind == TYPE;
return type.toInstance(sym, pre, clazz);
}
return map(type);
case SingleType(Type prefix, Symbol sym):
try {
return map(type);
} catch (Type.Malformed ex) {}
return apply(type.singleDeref());
default:
return map(type);
}
}
}
//where
Type toInstance(Symbol sym, Type pre, Symbol clazz) {
if (pre == NoType || clazz.kind != CLASS)
return this;
Symbol ownclass = sym.owner().constructorClass();
if (ownclass == clazz &&
pre.widen().symbol().isSubClass(ownclass)) {
switch (pre.baseType(ownclass)) {
case TypeRef(_, Symbol basesym, Type[] baseargs):
Symbol[] baseparams = basesym.typeParams();
for (int i = 0; i < baseparams.length; i++) {
if (sym == baseparams[i]) return baseargs[i];
}
//System.out.println(sym + " " + basesym + " " + ArrayApply.toString(baseparams));//DEBUG
break;
case ErrorType:
return ErrorType;
}
throw new ApplicationError(
this + " in " + ownclass + " cannot be instantiated from " + pre.widen()
);
} else {
return toInstance(sym, pre.baseType(clazz).prefix(), clazz.owner());
}
}
Type toPrefix(Symbol sym, Type pre, Symbol clazz) {
//System.out.println(this + ".toPrefix(" + sym + "," + pre + "," + clazz + ")");//DEBUG
if (pre == NoType || clazz.kind != CLASS)
return this;
else if (sym.isSubClass(clazz) &&
pre.widen().symbol().isSubClass(sym))
return pre;
else
return toPrefix(sym, pre.baseType(clazz).prefix(), clazz.owner());
}
/** This type as seen from prefix `pre' and class `clazz'. This means:
* Replace all thistypes of `clazz' or one of its subclasses by `pre'
* and instantiate all parameters by arguments of `pre'.
* Proceed analogously for thistypes referring to outer classes.
*/
public Type asSeenFrom(Type pre, Symbol clazz) {
//System.out.println("computing asseenfrom of " + this + " with " + pre + "," + clazz);//DEBUG
return new AsSeenFromMap(pre, clazz).apply(this);
}
/** Types `these' as seen from prefix `pre' and class `clazz'.
*/
public static Type[] asSeenFrom(Type[] these, Type pre, Symbol clazz) {
return new AsSeenFromMap(pre, clazz).map(these);
}
/** The info of `sym', seen as a member of this type.
*/
public Type memberInfo(Symbol sym) {
return sym.info().asSeenFrom(this, sym.owner());
}
/** The type of `sym', seen as a member of this type.
*/
public Type memberType(Symbol sym) {
return sym.type().asSeenFrom(this, sym.owner());
}
/** The stabilized type of `sym', seen as a member of this type.
*/
public Type memberStabilizedType(Symbol sym) {
return sym.isStable() && this.isStable()
? Type.singleTypeMethod(this, sym)
: this.memberType(sym);
}
/** The low bound of `sym', seen as a member of this type.
*/
public Type memberLoBound(Symbol sym) {
return sym.loBound().asSeenFrom(this, sym.owner());
}
/** The view bound of `sym', seen as a member of this type.
*/
public Type memberVuBound(Symbol sym) {
return sym.vuBound().asSeenFrom(this, sym.owner());
}
// Substitutions ---------------------------------------------------------------
/** A common map superclass for symbol/symbol and type/symbol substitutions.
*/
public static abstract class SubstMap extends Map {
private Symbol[] from;
SubstMap(Symbol[] from) {
this.from = from;
}
public boolean matches(Symbol sym1, Symbol sym2) {
return sym1 == sym2;
}
/** Produce replacement type
* @param i The index in `from' of the symbol to be replaced.
* @param fromtp The type referring to this symbol.
*/
protected abstract Type replacement(int i, Type fromtp);
/** Produce new substitution where some symbols are excluded.
* @param newfrom The new array of from symbols (without excluded syms)
* @param excluded The array of excluded sysmbols
*/
protected abstract SubstMap exclude(Symbol[] newfrom, Symbol[] excluded);
public Type apply(Type t) {
switch (t) {
case TypeRef(NoPrefix, Symbol sym, Type[] args):
for (int i = 0; i < from.length; i++) {
if (matches(sym, from[i])) return replacement(i, t);
}
break;
case SingleType(NoPrefix, Symbol sym):
for (int i = 0; i < from.length; i++) {
if (matches(sym, from[i])) return replacement(i, t);
}
break;
case PolyType(Symbol[] tparams, Type result):
Symbol[] from1 = excludeSyms(from, tparams, from);
if (from1 != from) {
SubstMap f = exclude(from1, tparams);
Symbol[] tparams1 = f.map(tparams);
Type result1 = f.apply(result);
if (tparams1 != tparams)
result1 = result1.subst(tparams, tparams1);
if (tparams1 == tparams && result1 == result) return t;
else return PolyType(tparams1, result1);
}
}
return map(t);
}
//where
private boolean contains1(Symbol[] syms, Symbol sym) {
int i = 0;
while (i < syms.length && syms[i] != sym) i++;
return i < syms.length;
}
private int nCommon(Symbol[] from, Symbol[] tparams) {
int cnt = 0;
for (int i = 0; i < from.length; i++) {
if (contains1(tparams, from[i])) cnt++;
}
return cnt;
}
private Symbol[] excludeSyms(Symbol[] from, Symbol[] tparams, Symbol[] syms) {
int n = nCommon(from, tparams);
if (n == 0) {
return syms;
} else {
Symbol[] syms1 = new Symbol[syms.length - n];
int j = 0;
for (int i = 0; i < from.length; i++) {
if (!contains1(tparams, from[i])) syms1[j++] = syms[i];
}
return syms1;
}
}
private Type[] excludeTypes(Symbol[] from, Symbol[] tparams, Type[] types) {
int n = nCommon(from, tparams);
if (n == 0) {
return types;
} else {
Type[] types1 = new Type[types.length - n];
int j = 0;
for (int i = 0; i < from.length; i++) {
if (!contains1(tparams, from[i])) types1[j++] = types[i];
}
return types1;
}
}
}
/** A map for symbol/symbol substitutions
*/
public static class SubstSymMap extends SubstMap {
Symbol[] to;
protected SubstSymMap(Symbol[] from, Symbol[] to) {
super(from);
this.to = to;
}
protected Type replacement(int i, Type fromtp) {
switch (fromtp) {
case TypeRef(Type pre, Symbol sym, Type[] args):
return typeRef(pre, to[i], args);
case SingleType(Type pre, Symbol sym):
return singleType(pre, to[i]);
default:
throw new ApplicationError();
}
}
protected SubstMap exclude(Symbol[] newfrom, Symbol[] excluded) {
return new SubstSymMap(newfrom, excludeSyms(from, excluded, to));
}
}
/** A map for type/symbol substitutions
*/
public static class SubstTypeMap extends SubstMap {
Type[] to;
public SubstTypeMap(Symbol[] from, Type[] to) {
super(from);
this.to = to;
}
public Type replacement(int i, Type fromtp) {
return to[i];
}
public SubstMap exclude(Symbol[] newfrom, Symbol[] excluded) {
return new SubstTypeMap(newfrom, excludeTypes(from, excluded, to));
}
}
/** A map for symbol/symbol substitutions which, instead of
* cloning parameters, updates their symbol's types.
*/
public static class UpdateSubstSymMap extends SubstSymMap {
protected UpdateSubstSymMap(Symbol[] from, Symbol[] to) {
super(from, to);
}
public Type apply(Type t) {
switch (t) {
case PolyType(Symbol[] params, Type result):
// !!! Also update loBounds? How? loBound can only be set!
for (int i = 0; i < params.length; i++) {
Type tp = params[i].nextType();
Type tp1 = apply(tp);
if (tp != tp1) params[i].updateInfo(tp1);
}
Type result1 = apply(result);
if (result1 == result) return t;
else return Type.PolyType(params, result1);
case MethodType(Symbol[] params, Type result):
for (int i = 0; i < params.length; i++) {
Type tp = params[i].nextType();
Type tp1 = apply(tp);
if (tp != tp1) params[i].updateInfo(tp1);
}
Type result1 = apply(result);
if (result1 == result) return t;
else return Type.MethodType(params, result1);
default:
return super.apply(t);
}
}
public Symbol map(Symbol sym, boolean dontClone) { return sym; }
public Symbol[] map(Symbol[] syms, boolean dontClone) { return syms; }
public Scope map(Scope s) { return s; }
}
/** Returns the given non-updating symbol/symbol substitution. */
public static Map getSubst(Symbol[] from, Symbol[] to) {
return getSubst(from, to, false);
}
/** Returns the given (updating?) symbol/symbol substitution. */
public static Map getSubst(Symbol[] from, Symbol[] to, boolean update) {
if (from.length == 0 && to.length == 0) return IdMap;
if (update) return new UpdateSubstSymMap(from, to);
return new SubstSymMap(from, to);
}
/** Returns the given non-updating symbol/type substitution. */
public static Map getSubst(Symbol[] from, Type[] to) {
if (from.length == 0 && to.length == 0) return IdMap;
return new SubstTypeMap(from, to);
}
/** Substitute symbols `to' for occurrences of symbols `from' in this type.
*/
public Type subst(Symbol[] from, Symbol[] to) {
if (to.length != 0 && from != to) {//!!!
assert from.length == to.length
: this + ": " + from.length + " != " + to.length;
return new SubstSymMap(from, to).apply(this);
} else return this;
}
/** Substitute symbols `to' for occurrences of symbols `from' in these types.
*/
public static Type[] subst(Type[] these, Symbol[] from, Symbol[] to) {
if (these.length != 0 && to.length != 0 && from != to) {
assert from.length == to.length;
return new SubstSymMap(from, to).map(these);
} else return these;
}
/** Substitute types `to' for occurrences of symbols `from' in this type.
*/
public Type subst(Symbol[] from, Type[] to) {
if (to.length != 0) {
assert from.length == to.length
: this + ": " + Debug.show(from) + " <> " + ArrayApply.toString(to);
return new SubstTypeMap(from, to).apply(this);
} else return this;
}
/** Substitute types `to' for occurrences of symbols `from' in these types.
*/
public static Type[] subst(Type[] these, Symbol[] from, Type[] to) {
if (these.length != 0 && to.length != 0) {
assert from.length == to.length;
return new SubstTypeMap(from, to).map(these);
} else return these;
}
/**
* A map that substitutes ThisTypes of a given class by a given
* type. All occurrences of the type parameters of the given class
* are replaced by the type arguments extracted from the given
* type. Furthermore, the prefixes of the given type are used to
* substitute, in the same way, the ThisTypes of the outer classes
* of the given class.
*
* object Foo {
* class C[D] { class I[J]; }
* val c: C[Int] = new C[Int];
* class M[N] extends c.I[N];
* }
*
* In the code above, a ThisTypeMap of class "I" and type
* "ThisType(M)", would do the following substitutions:
*
* - ThisType(I) -> ThisType(M)
* - TypeRef(_, J, _) -> TypeRef(_, N, -)
* - ThisType(C) -> SingleType(ThisType(Foo), c)
* - TypeRef(_, D, _) -> TypeRef(_, Int, _)
*/
private static class ThisTypeMap extends Map {
private static Map create(Symbol clasz, Type type) {
HashMap subst = getSubst(clasz, type, 0);
return subst == null ? IdMap : new ThisTypeMap(subst);
}
private static HashMap getSubst(Symbol clasz, Type type, int capacity){
switch (type) {
case NoPrefix:
return getSubst(capacity);
case ThisType(Symbol symbol):
if (symbol == clasz) return getSubst(capacity);
}
Type base = type.baseType(clasz);
switch (base) {
case TypeRef(Type prefix, Symbol symbol, Type[] args):
capacity += 1 + args.length;
HashMap subst = getSubst(clasz.owner(), prefix, capacity);
subst.put(clasz, type);
Symbol[] params = clasz.typeParams();
assert symbol == clasz && args.length == params.length:
type + " @ " + Debug.show(clasz) + " -> " + base;
for (int i = 0; i < params.length; i++) {
assert params[i].isParameter(): Debug.show(params[i]);
subst.put(params[i], args[i]);
}
return subst;
default:
throw Debug.abort("illegal case",
type + " @ " + Debug.show(clasz) + " -> " + base);
}
}
private static HashMap getSubst(int capacity) {
return capacity == 0 ? null : new HashMap(capacity);
}
private final HashMap/*<Symbol,Type>*/ subst;
private ThisTypeMap(HashMap subst) {
this.subst = subst;
}
public Type apply(Type type) {
switch (type) {
case ThisType(Symbol symbol):
Object lookup = subst.get(symbol);
if (lookup == null) break;
return (Type)lookup;
case TypeRef(NoPrefix, Symbol symbol, Type[] args):
if (!symbol.isParameter()) break;
assert args.length == 0: type;
Object lookup = subst.get(symbol);
if (lookup == null) break;
return (Type)lookup;
}
return map(type);
}
public String toString() {
return subst.toString();
}
}
/** Returns a ThisTypeMap of given class and type. */
public static Map getThisTypeMap(Symbol clasz, Type type) {
return ThisTypeMap.create(clasz, type);
}
/** A map for substitutions of thistypes.
*/
public static class SubstThisMap extends Map {
Symbol from;
Type to;
public SubstThisMap(Symbol from, Type to) {
this.from = from;
this.to = to;
}
public SubstThisMap(Symbol oldSym, Symbol newSym) {
this(oldSym, newSym.thisType());
}
public Type apply(Type type) {
switch (type) {
case ThisType(Symbol sym):
return sym == from ? to : type;
default:
return map(type);
}
}
}
public Type substThis(Symbol from, Type to) {
return new SubstThisMap(from, to).apply(this);
}
public static Type[] substThis(Type[] these, Symbol from, Type to) {
return new SubstThisMap(from, to).map(these);
}
static class ContainsMap extends Map {
boolean result = false;
Symbol sym;
ContainsMap(Symbol sym) {
this.sym = sym;
}
public Type apply(Type t) {
if (!result) {
switch (t) {
case TypeRef(Type pre, Symbol sym1, Type[] args):
if (sym == sym1) result = true;
else { map(pre); map(args); }
break;
case SingleType(Type pre, Symbol sym1):
map(pre);
if (sym == sym1) result = true;
break;
default:
map(t);
}
}
return t;
}
}
/** Does this type contain symbol `sym'?
*/
public boolean contains(Symbol sym) {
ContainsMap f = new ContainsMap(sym);
f.apply(this);
return f.result;
}
/** Does this type contain any of the symbols `syms'?
*/
public boolean containsSome(Symbol[] syms) {
for (int i = 0; i < syms.length; i++)
if (contains(syms[i])) return true;
return false;
}
// Cloning ---------------------------------------------------------------
/** Returns a shallow copy of the given array. */
public static Type[] cloneArray(Type[] array) {
return cloneArray(0, array, 0);
}
/**
* Returns a shallow copy of the given array prefixed by "prefix"
* null items.
*/
public static Type[] cloneArray(int prefix, Type[] array) {
return cloneArray(prefix, array, 0);
}
/**
* Returns a shallow copy of the given array suffixed by "suffix"
* null items.
*/
public static Type[] cloneArray(Type[] array, int suffix) {
return cloneArray(0, array, suffix);
}
/**
* Returns a shallow copy of the given array prefixed by "prefix"
* null items and suffixed by "suffix" null items.
*/
public static Type[] cloneArray(int prefix, Type[] array, int suffix) {
assert prefix >= 0 && suffix >= 0: prefix + " - " + suffix;
int size = prefix + array.length + suffix;
if (size == 0) return EMPTY_ARRAY;
Type[] clone = new Type[size];
for (int i = 0; i < array.length; i++) clone[prefix + i] = array[i];
return clone;
}
/** Returns the concatenation of the two arrays. */
public static Type[] concat(Type[] array1, Type[] array2) {
if (array1.length == 0) return array2;
if (array2.length == 0) return array1;
Type[] clone = cloneArray(array1.length, array2);
for (int i = 0; i < array1.length; i++) clone[i] = array1[i];
return clone;
}
/**
* Clones a type i.e. returns a new type where all symbols in
* MethodTypes and PolyTypes and CompoundTypes have been cloned.
*/
public Type cloneType(Symbol oldOwner, Symbol newOwner) {
SymbolCloner cloner = new SymbolCloner();
cloner.owners.put(oldOwner, newOwner);
return cloner.cloneType(this);
}
/**
* Clones a type i.e. returns a new type where all symbols in
* MethodTypes and PolyTypes have been cloned. This method
* performs no substitution on the type of the cloned symbols.
* Typically, the type of those symbols will be fixed later by
* applying some Map.applyParams method to the returned type.
*/
public Type cloneTypeNoSubst(SymbolCloner cloner) {
switch (this) {
case MethodType(Symbol[] vparams, Type result):
Symbol[] clones = cloner.cloneSymbols(vparams);
return Type.MethodType(clones, result.cloneTypeNoSubst(cloner));
case PolyType(Symbol[] tparams, Type result):
Symbol[] clones = cloner.cloneSymbols(tparams);
return Type.PolyType(clones, result.cloneTypeNoSubst(cloner));
default:
return this;
}
}
// Comparisons ------------------------------------------------------------------
/** Type relations */
public static class Relation {
public case SubType; // this SubType that <=> this.isSubType(that)
public case SameType; // this SameType that <=> this.isSameAs(that)
public case SuperType; // this SuperType that <=> that.isSubType(this)
public String toString() {
return toString(false);
}
public String toString(boolean negate) {
switch (this) {
case SubType : return negate ? "!<=" : "<=";
case SameType : return negate ? "!==" : "=";
case SuperType: return negate ? "!>=" : ">=";
default : throw Debug.abort("unknown relation", this);
}
}
}
/** Is this type in given relation to that type?
*/
public boolean compareTo(Type that, Relation relation) {
switch (relation) {
case SubType : return this.isSubType(that);
case SameType : return this.isSameAs(that);
case SuperType: return that.isSubType(this);
default : throw Debug.abort("unknown relation", relation);
}
}
/** Is this type a subtype of that type?
*/
public boolean isSubType(Type that) {
if (explainSwitch) {
for (int i = 0; i < indent; i++) System.out.print(" ");
System.out.println(this + " < " + that + "?");
indent++;
}
boolean result = isSubType0(that);
if (explainSwitch) {
indent--;
for (int i = 0; i < indent; i++) System.out.print(" ");
System.out.println(result);
}
return result;
}
public boolean isSubType0(Type that) {
if (this == that) return true;
switch (this) {
case ErrorType:
case AnyType:
return true;
}
switch (that) {
case ErrorType:
case AnyType:
return true;
case NoType:
case NoPrefix:
return false;
case ThisType(_):
case SingleType(_, _):
switch (this) {
case ThisType(_):
case SingleType(_, _):
return this.isSameAs(that);
}
break;
case ConstantType(_, _):
switch (this) {
case ConstantType(Type base, _):
return this.isSameAs(that) || base.isSubType(that);
}
break;
case TypeRef(Type pre1, Symbol sym1, Type[] args1):
switch (this) {
case TypeRef(Type pre, Symbol sym, Type[] args):
if (sym == sym1 && pre.isSubType(pre1) &&
isSubArgs(args, args1, sym.typeParams())
||
sym.kind == TYPE && pre.memberInfo(sym).isSubType(that))
return true;
break;
}
if (sym1.kind == CLASS) {
Type base = this.baseType(sym1);
if (this != base && base.isSubType(that))
return true;
}
break;
case CompoundType(Type[] parts1, Scope members1):
int i = 0;
while (i < parts1.length && isSubType(parts1[i])) i++;
if (i == parts1.length && specializes(members1))
return true;
break;
case MethodType(Symbol[] ps1, Type res1):
switch (this) {
case MethodType(Symbol[] ps, Type res):
if (ps.length != ps1.length) return false;
for (int i = 0; i < ps.length; i++) {
Symbol p1 = ps1[i];
Symbol p = ps[i];
if (!p1.type().isSameAs(p.type()) ||
(p1.flags & (DEF | REPEATED)) != (p.flags & (DEF | REPEATED)))
return false;
}
return res.isSubType(res1);
}
break;
case PolyType(Symbol[] ps1, Type res1):
switch (this) {
case PolyType(Symbol[] ps, Type res):
if (ps.length != ps1.length) return false;
for (int i = 0; i < ps.length; i++)
if (!ps1[i].info().subst(ps1, ps).isSameAs(ps[i].info()) ||
!ps[i].loBound().isSameAs(ps1[i].loBound().subst(ps1, ps)) ||
!ps[i].vuBound().isSameAs(ps1[i].vuBound().subst(ps1, ps)))
return false;
return res.isSubType(res1.subst(ps1, ps));
}
break;
case OverloadedType(Symbol[] alts1, Type[] alttypes1):
for (int i = 0; i < alttypes1.length; i++) {
if (!isSubType(alttypes1[i]))
return false;
}
return true;
case UnboxedType(int tag1):
switch (this) {
case UnboxedType(int tag):
return tag == tag1;
}
break;
case UnboxedArrayType(Type elemtp1):
switch (this) {
case UnboxedArrayType(Type elemtp):
return elemtp.isSubType(elemtp1);
}
break;
case TypeVar(Type origin, Constraint constr):
//todo: should we test for equality with origin?
if (constr.inst != NoType) {
return this.isSubType(constr.inst);
} else {
constr.lobounds = new List(this, constr.lobounds);
return true;
}
default:
throw new ApplicationError(this + " <: " + that);
}
switch (this) {
case NoType:
case NoPrefix:
return false;
case ThisType(_):
case SingleType(_, _):
if (this.singleDeref().isSubType(that)) return true;
break;
case ConstantType(_, _):
if (this.singleDeref().isSubType(that)) return true;
break;
case TypeVar(Type origin, Constraint constr):
if (constr.inst != NoType) {
return constr.inst.isSubType(that);
} else {
constr.hibounds = new List(that, constr.hibounds);
return true;
}
case TypeRef(_, Symbol sym, _):
switch (that) {
case TypeRef(_, Symbol sym1, _):
if (sym1.kind == TYPE && this.isSubType(that.loBound()))
return true;
}
if (sym == Global.instance.definitions.ALL_CLASS)
return that.isSubType(Global.instance.definitions.ANY_TYPE());
else if (sym == Global.instance.definitions.ALLREF_CLASS)
return
that.symbol() == Global.instance.definitions.ANY_CLASS ||
(that.symbol() != Global.instance.definitions.ALL_CLASS &&
that.isSubType(Global.instance.definitions.ANYREF_TYPE()));
break;
case OverloadedType(Symbol[] alts, Type[] alttypes):
for (int i = 0; i < alttypes.length; i++) {
if (alttypes[i].isSubType(that)) return true;
}
break;
case CompoundType(Type[] parts, Scope members):
int i = 0;
while (i < parts.length) {
if (parts[i].isSubType(that)) return true;
i++;
}
break;
case UnboxedArrayType(_):
if (Global.instance.definitions.OBJECT_TYPE().isSubType(that))
return true;
// !!! we should probably also test for Clonable, Serializable, ...
}
return false;
}
/** Are types `these' subtypes of corresponding types `those'?
*/
public static boolean isSubType(Type[] these, Type[] those) {
if (these.length != those.length) return false;
for (int i = 0; i < these.length; i++) {
if (!these[i].isSubType(those[i])) return false;
}
return true;
}
/** Are types `these' arguments types conforming to corresponding types `those'?
*/
static boolean isSubArgs(Type[] these, Type[] those, Symbol[] tparams) {
if (these.length != those.length) return false;
for (int i = 0; i < these.length; i++) {
if ((tparams[i].flags & COVARIANT) != 0) {
if (!these[i].isSubType(those[i])) return false;
} else if ((tparams[i].flags & CONTRAVARIANT) != 0) {
//System.out.println("contra: " + these[i] + " " + those[i] + " " + those[i].isSubType(these[i]));//DEBUG
if (!those[i].isSubType(these[i])) return false;
} else {
if (!these[i].isSameAs(those[i])) return false;
}
}
return true;
}
public static boolean isSubSet(Type[] alts, Type[] alts1) {
for (int i = 0; i < alts.length; i++) {
int j = 0;
while (j < alts1.length && !alts1[j].isSameAs(alts[i])) j++;
if (j == alts1.length) return false;
}
return true;
}
/** Does this type implement all symbols in scope `s' with same or stronger types?
*/
public boolean specializes(Scope s) {
for (Scope.SymbolIterator it = s.iterator(true); it.hasNext();) {
if (!specializes(it.next())) return false;
}
return true;
}
/** Does this type implement symbol `sym1' with same or stronger type?
*/
public boolean specializes(Symbol sym1) {
if (explainSwitch) {
for (int i = 0; i < indent; i++) System.out.print(" ");
System.out.println(this + " specializes " + sym1 + "?");
indent++;
}
boolean result = specializes0(sym1);
if (explainSwitch) {
indent--;
for (int i = 0; i < indent; i++) System.out.print(" ");
System.out.println(result);
}
return result;
}
private boolean specializes0(Symbol sym1) {
Type self = narrow();
Symbol[] tparams = symbol().typeParams();
Type[] targs = typeArgs();
Symbol sym = lookup(sym1.name);
return
sym.kind != NONE &&
(sym == sym1
||
(sym.kind == sym1.kind || sym1.kind == TYPE) &&
self.memberInfo(sym).subst(tparams, targs)
.isSubType(sym1.info().substThis(sym1.owner(), self)) &&
sym1.loBound().substThis(sym1.owner(), self)
.isSubType(self.memberLoBound(sym).subst(tparams, targs)) &&
self.memberVuBound(sym).subst(tparams, targs)
.isSubType(sym1.vuBound().substThis(sym1.owner(), self))
||
(sym.kind == TYPE && sym1.kind == ALIAS &&
sym1.info().unalias().isSameAs(sym.type())));
}
/** Is this type the same as that type?
*/
public boolean isSameAs(Type that) {
if (explainSwitch) {
for (int i = 0; i < indent; i++) System.out.print(" ");
System.out.println(this + " = " + that + "?");
indent++;
}
boolean result = isSameAs0(that);
if (explainSwitch) {
indent--;
for (int i = 0; i < indent; i++) System.out.print(" ");
System.out.println(result);
}
return result;
}
public boolean isSameAs0(Type that) {
if (this == that) return true;
switch (this) {
case ErrorType:
case AnyType:
return true;
case ThisType(Symbol sym):
switch (that) {
case ThisType(Symbol sym1):
return sym == sym1;
case SingleType(Type pre1, Symbol sym1):
return sym1.isModule()
&& sym == sym1.moduleClass()
&& sym.owner().thisType().isSameAs(pre1)
||
deAlias(that) != that &&
this.isSameAs(deAlias(that));
}
break;
case SingleType(Type pre, Symbol sym):
switch (that) {
case SingleType(Type pre1, Symbol sym1):
return sym == sym1 && pre.isSameAs(pre1)
||
(deAlias(this) != this || deAlias(that) != that) &&
deAlias(this).isSameAs(deAlias(that));
case ThisType(Symbol sym1):
return sym.isModule()
&& sym.moduleClass() == sym1
&& pre.isSameAs(sym1.owner().thisType())
||
deAlias(this) != this &&
deAlias(this).isSameAs(that);
default:
if (deAlias(this) != this)
return deAlias(this).isSameAs(that);
}
break;
case ConstantType(Type base, AConstant value):
switch (that) {
case ConstantType(Type base1, AConstant value1):
return base.isSameAs(base1) && value.equals(value1);
}
break;
case TypeRef(Type pre, Symbol sym, Type[] args):
switch (that) {
case TypeRef(Type pre1, Symbol sym1, Type[] args1):
if (sym == sym1 && pre.isSameAs(pre1) && isSameAs(args, args1))
return true;
}
break;
case CompoundType(Type[] parts, Scope members):
switch (that) {
case CompoundType(Type[] parts1, Scope members1):
if (parts.length != parts1.length) return false;
for (int i = 0; i < parts.length; i++)
if (!parts[i].isSameAs(parts1[i])) return false;
return isSameAs(members, members1);
}
break;
case MethodType(Symbol[] ps, Type res):
switch (that) {
case MethodType(Symbol[] ps1, Type res1):
if (ps.length != ps1.length) return false;
for (int i = 0; i < ps.length; i++) {
Symbol p1 = ps1[i];
Symbol p = ps[i];
if (!p1.type().isSameAs(p.type()) ||
(p1.flags & (DEF | REPEATED)) != (p.flags & (DEF | REPEATED)))
return false;
}
return res.isSameAs(res1);
}
break;
case PolyType(Symbol[] ps, Type res):
switch (that) {
case PolyType(Symbol[] ps1, Type res1):
if (ps.length != ps1.length) return false;
for (int i = 0; i < ps.length; i++)
if (!ps1[i].info().subst(ps1, ps).isSameAs(ps[i].info()) ||
!ps1[i].loBound().subst(ps1, ps).isSameAs(ps[i].loBound()) ||
!ps1[i].vuBound().subst(ps1, ps).isSameAs(ps[i].vuBound()))
return false;
return res.isSameAs(res1.subst(ps1, ps));
}
break;
case OverloadedType(Symbol[] alts, Type[] alttypes):
switch (that) {
case OverloadedType(Symbol[] alts1, Type[] alttypes1):
return isSubSet(alttypes1, alttypes)
&& isSubSet(alttypes, alttypes1);
}
break;
case UnboxedType(int kind):
switch (that) {
case UnboxedType(int kind1):
return kind == kind1;
}
break;
case UnboxedArrayType(Type elemtp):
switch (that) {
case UnboxedArrayType(Type elemtp1):
return elemtp.isSameAs(elemtp1);
}
break;
}
switch (that) {
case ErrorType:
case AnyType:
return true;
case NoType:
case NoPrefix:
return false;
case TypeVar(Type origin, Constraint constr):
if (constr.inst != NoType) return constr.inst.isSameAs(this);
else return constr.instantiate(this.any2typevar());
}
switch (this) {
case NoType:
case NoPrefix:
return false;
case TypeVar(Type origin, Constraint constr):
if (constr.inst != NoType) return constr.inst.isSameAs(that);
else return constr.instantiate(that.any2typevar());
}
return false;
}
//where
Type deAlias(Type tp) {
switch (tp) {
case SingleType(_, _):
Type tp1 = tp.singleDeref();
if (tp1.isStable()) return deAlias(tp1);
}
return tp;
}
/** Are types `these' the same as corresponding types `those'?
*/
public static boolean isSameAs(Type[] these, Type[] those) {
if (these.length != those.length) return false;
for (int i = 0; i < these.length; i++) {
if (!these[i].isSameAs(those[i])) return false;
}
return true;
}
/** Do scopes `s1' and `s2' define he same symbols with the same kinds and infos?
*/
public boolean isSameAs(Scope s1, Scope s2) {
return isSubScope(s1, s2) && isSubScope(s2, s1);
}
/** Does scope `s1' define all symbols of scope `s2' with the same kinds and infos?
*/
private boolean isSubScope(Scope s1, Scope s2) {
for (Scope.SymbolIterator it = s2.iterator(); it.hasNext(); ) {
Symbol sym2 = it.next();
Symbol sym1 = s1.lookup(sym2.name);
if (sym1.kind != sym2.kind ||
!sym1.info().isSameAs(
sym2.info().substThis(
sym2.owner(), sym1.owner().thisType())) ||
!sym1.loBound().isSameAs(
sym2.loBound().substThis(
sym2.owner(), sym1.owner().thisType())) ||
!sym1.vuBound().isSameAs(
sym2.vuBound().substThis(
sym2.owner(), sym1.owner().thisType())))
return false;
}
return true;
}
boolean isSameAsAll(Type[] tps) {
int i = 1;
while (i < tps.length && isSameAs(tps[i])) i++;
return i == tps.length;
}
/** Map every occurrence of AnyType to a fresh type variable.
*/
public static Map any2typevarMap = new Map() {
public Type apply(Type t) { return t.any2typevar(); }
};
public Type any2typevar() {
switch (this) {
case AnyType:
return TypeVar(this, new Constraint());
default:
return any2typevarMap.map(this);
}
}
// Closures and Least Upper Bounds ---------------------------------------------------
/** The closure of this type, i.e. the widened type itself followed by all
* its direct and indirect (pre-) base types, sorted by Symbol.isLess().
*/
public Type[] closure() {
switch (this.widen().unalias()) {
case TypeRef(Type pre, Symbol sym, Type[] args):
return subst(
asSeenFrom(sym.closure(), pre, sym.owner()),
sym.typeParams(), args);
case CompoundType(Type[] parts, Scope members):
/*
if (symbol().isCompoundSym()) {
Type[][] closures = new Type[parts.length][];
for (int i = 0; i < parts.length; i++)
closures[i] = parts[i].closure();
return union(closures);
} else {
*/
return symbol().closure();
default:
return new Type[]{this};
}
}
/** return union of array of closures. It is assumed that
* for any two base types with the same class symbols the later one
* is a subtype of the former.
*/
static private Type[] union(Type[][] closures) {
if (closures.length == 1) return closures[0]; // fast special case
int[] index = new int[closures.length];
int totalsize = 0;
for (int i = 0; i < index.length; i++) {
index[i] = 0;
totalsize = totalsize + closures[i].length;
}
Type[] res = new Type[totalsize];
int j = 0;
while (true) {
// find minimal element
Type min = null;
for (int i = 0; i < index.length; i++) {
if (index[i] < closures[i].length) {
Type cltype = closures[i][index[i]];
if (min == null ||
cltype.symbol().isLess(min.symbol()) ||
cltype.symbol() == min.symbol()) {
min = cltype;
}
}
}
if (min == null) break;
res[j] = min;
j = j + 1;
// bump all indices that start with minimal element
for (int i = 0; i < index.length; i++) {
if (index[i] < closures[i].length &&
closures[i][index[i]].symbol() == min.symbol())
index[i] = index[i] + 1;
}
}
Type[] result = new Type[j];
System.arraycopy(res, 0, result, 0, j);
return result;
}
/** return intersection of non-empty array of closures
*/
static private Type[] intersection(Type[][] closures) {
if (closures.length == 1) return closures[0]; // fast special case
int[] index = new int[closures.length];
Type[] mintypes = new Type[closures.length];
int minsize = Integer.MAX_VALUE;
for (int i = 0; i < index.length; i++) {
index[i] = 0;
if (closures[i].length < minsize) minsize = closures[i].length;
}
Type[] res = new Type[minsize];
int j = 0;
L:
while (true) {
// find minimal element
Symbol minsym = null;
for (int i = 0; i < index.length; i++) {
if (index[i] == closures[i].length) break L;
Symbol clsym = closures[i][index[i]].symbol();
if (minsym == null || clsym.isLess(minsym)) minsym = clsym;
}
boolean agree = true;
// bump all indices that start with minimal element
for (int i = 0; i < index.length; i++) {
Type cltype = closures[i][index[i]];
if (cltype.symbol() == minsym) {
mintypes[i] = cltype;
index[i] = index[i] + 1;
} else {
agree = false;
}
}
if (agree) {
Type mintype = argLub(mintypes);
if (mintype.symbol().kind == CLASS) {
res[j] = mintype;
j = j + 1;
}
}
}
Type[] result = new Type[j];
System.arraycopy(res, 0, result, 0, j);
return result;
}
/** same as lub, but all types are instances of the same class,
* possibly with different prefixes and arguments.
*/
//todo: catch lubs not within bounds.
static Type argLub(Type[] tps) {
tps = elimRedundant(tps, true);
if (tps.length == 1) return tps[0];
Type pre = tps[0].prefix();
Symbol sym = tps[0].symbol();
Symbol[] tparams = sym.typeParams();
Type[] args = new Type[tparams.length];
Type[][] argss = new Type[args.length][tps.length];
for (int i = 0; i < tps.length; i++) {
switch (tps[i]) {
case TypeRef(Type pre1, Symbol sym1, Type[] args1):
assert sym == sym1;
assert args1.length == args.length;
if (!pre.isSameAs(pre1)) return NoType;
for (int j = 0; j < args1.length; j++)
argss[j][i] = args1[j];
break;
case ErrorType:
return ErrorType;
default:
assert false : tps[i];
}
}
for (int j = 0; j < args.length; j++) {
if ((tparams[j].flags & COVARIANT) != 0)
args[j] = lub(argss[j]);
else if ((tparams[j].flags & CONTRAVARIANT) != 0)
args[j] = glb(argss[j]);
else return NoType;
}
return typeRef(pre, sym, args);
}
/** The frontier of a closure C is the minimal set of types such that
* the union of the closures of these types equals C.
*/
static private Type[] frontier(Type[] closure) {
Type[] front = new Type[closure.length];
int j = 0;
for (int i = 0; i < closure.length; i++) {
int k = 0;
Type tp = closure[i];
while (k < j && !front[k].symbol().isSubClass(tp.symbol()))
k++;
if (k == j) {
front[j] = tp;
j++;
}
}
Type[] result = new Type[j];
System.arraycopy(front, 0, result, 0, j);
return result;
}
/** remove types that are subtypes of some other type.
*/
static private Type[] elimRedundant(Type[] tps, boolean elimLower) {
Type.List tl = Type.List.EMPTY;
int nredundant = 0;
boolean[] redundant = new boolean[tps.length];
for (int i = 0; i < tps.length; i++) {
switch (tps[i]) {
case ErrorType:
return new Type[]{ErrorType};
case MethodType(_, _):
case PolyType(_, _):
case OverloadedType(_, _):
return new Type[]{NoType};
default:
assert tps[i].isObjectType(): tps[i];
for (int j = 0; j < i && !redundant[i]; j++) {
if (!redundant[j]) {
if (tps[i].isSubType(tps[j])) {
redundant[elimLower ? i : j] = true;
nredundant++;
} else if (tps[j].isSubType(tps[i])) {
redundant[elimLower ? j : i] = true;
nredundant++;
}
}
}
}
}
if (nredundant != 0) {
Type[] tps1 = new Type[tps.length - nredundant];
int n = 0;
for (int i = 0; i < tps.length; i++) {
if (!redundant[i]) tps1[n++] = tps[i];
}
return tps1;
} else {
return tps;
}
}
static int recCount = 0;
static boolean giveUp = false;
static int recLimit = 10;
public static Type lub(Type[] tps) {
if (recCount == recLimit) {
giveUp = true;
return Global.instance.definitions.ANY_TYPE();
} else {
recCount++;
Type result = lub0(tps);
recCount--;
if (recCount == 0) {
if (giveUp) {
giveUp = false;
throw new Error("failure to compute least upper bound of types " +
ArrayApply.toString(tps, "", " and ", ";\n") +
"an approximation is: " + result + ";\n" +
"additional type annotations are needed");
} else {
giveUp = false;
}
}
return result;
}
}
/** Return the least upper bound of non-empty array of types `tps'.
*/
public static Type lub0(Type[] tps) {
//System.out.println("lub" + ArrayApply.toString(tps));//DEBUG
if (tps.length == 0) return Global.instance.definitions.ALL_TYPE();
//If all types are method types with same parameters,
//compute lub of their result types.
switch (tps[0]) {
case PolyType(Symbol[] tparams, _):
return polyLub(tps, tparams);
case MethodType(Symbol[] vparams, _):
return methodLub(tps, vparams);
}
// remove types that are subtypes of some other type.
tps = elimRedundant(tps, true);
if (tps.length == 1) return tps[0];
// intersect closures and build frontier.
Type[][] closures = new Type[tps.length][];
for (int i = 0; i < tps.length; i++) {
closures[i] = tps[i].closure();
}
Type[] allBaseTypes = intersection(closures);
Type[] leastBaseTypes = frontier(allBaseTypes);
assert leastBaseTypes.length > 0 : ArrayApply.toString(tps);
// add refinements where necessary
Scope members = new Scope();
Type lubType = compoundTypeWithOwner(Symbol.NONE, leastBaseTypes, members); // !!! NONE
/*
Type lubThisType = lubType.narrow();
//System.out.println("lubtype = " + lubType);//DEBUG
Symbol[] rsyms = new Symbol[tps.length];
Type[] rtps = new Type[tps.length];
Type[] rlbs = new Type[tps.length];
for (int i = 0; i < allBaseTypes.length; i++) {
for (Scope.SymbolIterator it = allBaseTypes[i].members().iterator();
it.hasNext(); ) {
Symbol sym = it.next();
Name name = sym.name;
if ((sym.flags & PRIVATE) == 0 && lubType.lookup(name) == sym) {
Type symType = memberTp(lubThisType, sym);
Type symLoBound = lubThisType.memberLoBound(sym);
int j = 0;
while (j < tps.length) {
rsyms[j] = tps[j].lookupNonPrivate(name);
if (rsyms[j] == sym) break;
rtps[j] = memberTp(tps[j], rsyms[j])
.substThis(tps[j].symbol(), lubThisType);
rlbs[j] = tps[j].memberLoBound(rsyms[j])
.substThis(tps[j].symbol(), lubThisType);
if (rtps[j].isSameAs(symType) &&
rlbs[j].isSameAs(symLoBound)) break;
j++;
}
if (j == tps.length) {
if (Global.instance.debug)
System.out.println("refinement lub for " +
ArrayApply.toString(rsyms) + ":" + ArrayApply.toString(rtps));//debug
Symbol lubSym = lub(rsyms, rtps, rlbs, lubType.symbol());
if (lubSym.kind != NONE &&
!(lubSym.kind == sym.kind &&
lubSym.info().isSameAs(symType) &&
lubSym.loBound().isSameAs(symType)))
members.enter(lubSym);
}
}
}
}
//System.out.print("lub "); System.out.print(ArrayApply.toString(tps)); System.out.println(" = " + lubType);//DEBUG
*/
if (leastBaseTypes.length == 1 && members.isEmpty())
return leastBaseTypes[0];
else return lubType;
}
//where
private static Type memberTp(Type base, Symbol sym) {
return sym.kind == CLASS ? base.memberType(sym) : base.memberInfo(sym);
}
private static Type polyLub(Type[] tps, Symbol[] tparams0) {
Type[][] hiboundss = new Type[tparams0.length][tps.length];
Type[][] loboundss = new Type[tparams0.length][tps.length];
Type[][] vuboundss = new Type[tparams0.length][tps.length];
Type[] restps = new Type[tps.length];
for (int i = 0; i < tps.length; i++) {
switch (tps[i]) {
case PolyType(Symbol[] tparams, Type restp):
if (tparams.length == tparams0.length) {
for (int j = 0; j < tparams0.length; j++) {
hiboundss[j][i] = tparams[j].info()
.subst(tparams, tparams0);
loboundss[j][i] = tparams[j].loBound()
.subst(tparams, tparams0);
vuboundss[j][i] = tparams[j].vuBound()
.subst(tparams, tparams0);
}
restps[i] = restp.subst(tparams, tparams0);
} else {
return Type.NoType;
}
break;
default:
return Type.NoType;
}
}
Type[] hibounds = new Type[tparams0.length];
Type[] lobounds = new Type[tparams0.length];
Type[] vubounds = new Type[tparams0.length];
for (int j = 0; j < tparams0.length; j++) {
hibounds[j] = glb(hiboundss[j]);
lobounds[j] = lub(loboundss[j]);
vubounds[j] = glb(vuboundss[j]);
}
Symbol[] tparams = new Symbol[tparams0.length];
for (int j = 0; j < tparams.length; j++) {
tparams[j] = tparams0[j].cloneSymbol(Symbol.NONE)
.setInfo(hibounds[j].subst(tparams0, tparams))
.setLoBound(lobounds[j].subst(tparams0, tparams))
.setVuBound(vubounds[j].subst(tparams0, tparams));
}
return Type.PolyType(tparams, lub(restps).subst(tparams0, tparams));
}
private static Type methodLub(Type[] tps, Symbol[] vparams0) {
Type[] restps = new Type[tps.length];
for (int i = 0; i < tps.length; i++) {
switch (tps[i]) {
case MethodType(Symbol[] vparams, Type restp):
if (vparams.length != vparams0.length)
return Type.NoType;
for (int j = 0; j < vparams.length; j++)
if (!vparams[j].type().isSameAs(vparams0[j].type()) ||
(vparams[j].flags & (DEF | REPEATED)) !=
(vparams0[j].flags & (DEF | REPEATED)))
return Type.NoType;
restps[i] = restp;
}
}
Symbol[] vparams = new Symbol[vparams0.length];
for (int j = 0; j < vparams.length; j++) {
vparams[j] = vparams0[j].cloneSymbol(Symbol.NONE);
}
return Type.MethodType(vparams, lub(restps));
}
private static Symbol lub(Symbol[] syms, Type[] tps, Type[] lbs, Symbol owner) {
//System.out.println("lub" + ArrayApply.toString(syms));//DEBUG
int lubKind = syms[0].kind;
for (int i = 1; i < syms.length; i++) {
Symbol sym = syms[i];
if (sym.isError()) return Symbol.NONE;
if (sym.isType() && sym.kind != lubKind) lubKind = TYPE;
}
if (lubKind == syms[0].kind && tps[0].isSameAsAll(tps)) {
return syms[0].cloneSymbol();
}
Type lubType = lub(tps);
if (lubType == Type.NoType) return Symbol.NONE;
Symbol lubSym;
switch (lubKind) {
case VAL:
lubSym = owner.newTerm(syms[0].pos, 0, syms[0].name);
break;
case TYPE: case ALIAS: case CLASS:
lubSym = owner.newAbstractType(syms[0].pos, 0, syms[0].name);
lubSym.setLoBound(glb(lbs));
break;
default:
throw new ApplicationError();
}
lubSym.setInfo(lubType.setOwner(lubSym));
return lubSym;
}
public static Type glb(Type[] tps) {
if (recCount == recLimit) {
giveUp = true;
return Global.instance.definitions.ALL_TYPE();
} else {
recCount++;
Type result = glb0(tps);
recCount--;
if (recCount == 0) {
if (giveUp) {
giveUp = false;
throw new Error("failure to compute greatest lower bound of types " +
ArrayApply.toString(tps, "", " and ", ";\n") +
"an approximation is: " + result + ";\n" +
"additional type annotations are needed");
} else {
giveUp = false;
}
}
return result;
}
}
public static Type glb0(Type[] tps) {
if (tps.length == 0) return Global.instance.definitions.ANY_TYPE();
// step one: eliminate redunandant types; return if one one is left
tps = elimRedundant(tps, false);
if (tps.length == 1) return tps[0];
// step two: build arrays of all typerefs and all refinements
Type.List treftl = Type.List.EMPTY;
Type.List comptl = Type.List.EMPTY;
for (int i = 0; i < tps.length; i++) {
switch (tps[i]) {
case TypeRef(_, _, _):
treftl = new Type.List(tps[i], treftl);
break;
case CompoundType(Type[] parents, Scope members):
if (!members.isEmpty())
comptl = new Type.List(tps[i], comptl);
for (int j = 0; j < parents.length; j++)
treftl = new Type.List(parents[j], treftl);
break;
case ThisType(_):
case SingleType(_, _):
case ConstantType(_, _):
return Global.instance.definitions.ALL_TYPE();
}
}
CompoundType glbType = compoundTypeWithOwner(Symbol.NONE, Type.EMPTY_ARRAY, new Scope()); // !!! NONE
Type glbThisType = glbType.narrow();
// step 3: compute glb of all refinements.
Scope members = Scope.EMPTY;
if (comptl != List.EMPTY) {
Type[] comptypes = comptl.toArrayReverse();
Scope[] refinements = new Scope[comptypes.length];
for (int i = 0; i < comptypes.length; i++)
refinements[i] = comptypes[i].members();
if (!setGlb(glbType.members, refinements, glbThisType)) {
// refinements don't have lower bound, so approximate
// by AllRef
glbType.members = Scope.EMPTY;
treftl = new Type.List(
Global.instance.definitions.ALLREF_TYPE(), treftl);
}
}
// eliminate redudant typerefs
Type[] treftypes = elimRedundant(treftl.toArrayReverse(), false);
if (treftypes.length != 1 || !glbType.members.isEmpty()) {
// step 4: replace all abstract types by their lower bounds.
boolean hasAbstract = false;
for (int i = 0; i < treftypes.length; i++) {
if (treftypes[i].unalias().symbol().kind == TYPE)
hasAbstract = true;
}
if (hasAbstract) {
treftl = Type.List.EMPTY;
for (int i = 0; i < treftypes.length; i++) {
if (treftypes[i].unalias().symbol().kind == TYPE)
treftl = new Type.List(treftypes[i].loBound(), treftl);
else
treftl = new Type.List(treftypes[i], treftl);
}
treftypes = elimRedundant(treftl.toArrayReverse(), false);
}
}
if (treftypes.length != 1) {
// step 5: if there are conflicting instantiations of same
// class, replace them by lub/glb of arguments or lower bound.
Type lb = NoType;
for (int i = 0;
i < treftypes.length &&
lb.symbol() != Global.instance.definitions.ALL_CLASS;
i++) {
for (int j = 0; j < i; j++) {
if (treftypes[j].symbol() == treftypes[i].symbol())
lb = argGlb(treftypes[j], treftypes[i]);
}
}
if (lb != NoType) return lb;
}
if (treftypes.length == 1 && glbType.members.isEmpty()) {
return treftypes[0];
} else {
glbType.parts = treftypes;
return glbType;
}
}
private static Type argGlb(Type tp1, Type tp2) {
switch (tp1) {
case TypeRef(Type pre1, Symbol sym1, Type[] args1):
switch (tp2) {
case TypeRef(Type pre2, Symbol sym2, Type[] args2):
assert sym1 == sym2;
if (pre1.isSameAs(pre2)) {
Symbol[] tparams = sym1.typeParams();
Type[] args = new Type[tparams.length];
for (int i = 0; i < tparams.length; i++) {
if (args1[i].isSameAs(args2[i]))
args[i] = args1[i];
else if ((tparams[i].flags & COVARIANT) != 0)
args[i]= lub(new Type[]{args1[i], args2[i]});
else if ((tparams[i].flags & CONTRAVARIANT) != 0)
args[i]= glb(new Type[]{args1[i], args2[i]});
else
return glb(new Type[]{tp1.loBound(), tp2.loBound()});
}
return typeRef(pre1, sym1, args);
}
}
}
return glb(new Type[]{tp1.loBound(), tp2.loBound()});
}
/** Set scope `result' to glb of scopes `ss'. Return true iff succeeded.
*/
private static boolean setGlb(Scope result, Scope[] ss, Type glbThisType) {
for (int i = 0; i < ss.length; i++)
for (Scope.SymbolIterator it = ss[i].iterator(); it.hasNext(); )
if (!addMember(result, it.next(), glbThisType)) return false;
return true;
}
/** Add member `sym' to scope `s'. If`s' has already a member with same name,
* overwrite its info/low bound to form glb of both symbols.
*/
private static boolean addMember(Scope s, Symbol sym, Type glbThisType) {
Type syminfo = sym.info().substThis(sym.owner(), glbThisType);
Type symlb = sym.loBound().substThis(sym.owner(), glbThisType);
Type symvb = sym.vuBound().substThis(sym.owner(), glbThisType);
Scope.Entry e = s.lookupEntry(sym.name);
if (e == Scope.Entry.NONE) {
Symbol sym1 = sym.cloneSymbol(glbThisType.symbol());
sym1.setInfo(syminfo);
if (sym1.kind == TYPE) {
sym1.setLoBound(symlb);
sym1.setVuBound(symvb);
}
s.enter(sym1);
} else {
Type einfo = e.sym.info();
if (einfo.isSameAs(syminfo)) {
} else if (einfo.isSubType(syminfo) && sym.kind != ALIAS) {
} else if (syminfo.isSubType(einfo) && e.sym.kind != ALIAS) {
e.sym.setInfo(syminfo);
} else if (sym.kind == VAL && e.sym.kind == VAL ||
sym.kind == TYPE && e.sym.kind == TYPE) {
e.sym.setInfo(glb(new Type[]{einfo, syminfo}).setOwner(e.sym));
} else {
return false;
}
if (e.sym.kind == TYPE && sym.kind == TYPE) {
Type elb = e.sym.loBound();
if (elb.isSameAs(symlb)) {
} else if (symlb.isSubType(elb)) {
} else if (elb.isSubType(symlb)) {
e.sym.setLoBound(symlb);
} else {
e.sym.setLoBound(lub(new Type[]{elb, symlb}));
}
Type evb = e.sym.vuBound();
if (evb.isSameAs(symvb)) {
} else if (evb.isSubType(symvb)) {
} else if (symvb.isSubType(evb)) {
e.sym.setVuBound(symvb);
} else {
e.sym.setVuBound(glb(new Type[]{evb, symvb}));
}
}
}
return true;
}
private static Type polyGlb(Type[] tps, Symbol[] tparams0) {
Type[][] hiboundss = new Type[tparams0.length][tps.length];
Type[][] loboundss = new Type[tparams0.length][tps.length];
Type[][] vuboundss = new Type[tparams0.length][tps.length];
Type[] restps = new Type[tps.length];
for (int i = 0; i < tps.length; i++) {
switch (tps[i]) {
case PolyType(Symbol[] tparams, Type restp):
if (tparams.length == tparams0.length) {
for (int j = 0; j < tparams0.length; j++) {
hiboundss[j][i] = tparams[j].info()
.subst(tparams, tparams0);
loboundss[j][i] = tparams[j].loBound()
.subst(tparams, tparams0);
vuboundss[j][i] = tparams[j].vuBound()
.subst(tparams, tparams0);
}
restps[i] = restp.subst(tparams, tparams0);
} else {
return Type.NoType;
}
break;
default:
return Type.NoType;
}
}
Type[] hibounds = new Type[tparams0.length];
Type[] lobounds = new Type[tparams0.length];
Type[] vubounds = new Type[tparams0.length];
for (int j = 0; j < tparams0.length; j++) {
hibounds[j] = lub(hiboundss[j]);
lobounds[j] = glb(loboundss[j]);
vubounds[j] = lub(vuboundss[j]);
}
Symbol[] tparams = new Symbol[tparams0.length];
for (int j = 0; j < tparams.length; j++) {
tparams[j] = tparams0[j].cloneSymbol(Symbol.NONE)
.setInfo(hibounds[j].subst(tparams0, tparams))
.setLoBound(lobounds[j].subst(tparams0, tparams))
.setVuBound(vubounds[j].subst(tparams0, tparams));
}
return Type.PolyType(tparams, glb(restps).subst(tparams0, tparams));
}
private static Type methodGlb(Type[] tps, Symbol[] vparams0) {
Type[] restps = new Type[tps.length];
for (int i = 0; i < tps.length; i++) {
switch (tps[i]) {
case MethodType(Symbol[] vparams, Type restp):
if (vparams.length != vparams0.length)
return Type.NoType;
for (int j = 0; j < vparams.length; j++)
if (!vparams[i].type().isSameAs(vparams0[i].type()) ||
(vparams[i].flags & (DEF | REPEATED)) !=
(vparams0[i].flags & (DEF | REPEATED)))
return Type.NoType;
restps[i] = restp;
}
}
Symbol[] vparams = new Symbol[vparams0.length];
for (int j = 0; j < vparams.length; j++) {
vparams[j] = vparams0[j].cloneSymbol(Symbol.NONE);
}
return Type.MethodType(vparams, glb(restps));
}
// Erasure --------------------------------------------------------------------------
public static Map erasureMap = new MapOnlyTypes() {
public Type apply(Type t) { return t.erasure(); }
};
private static final Type[] unboxedType =
new Type[LastUnboxedTag + 1 - FirstUnboxedTag];
private static final Name[] unboxedName =
new Name[LastUnboxedTag + 1 - FirstUnboxedTag];
private static final Symbol[] boxedSymbol =
new Symbol[LastUnboxedTag + 1 - FirstUnboxedTag];
private static void mkStdClassType(int kind, String unboxedstr, Symbol boxedsym) {
unboxedType[kind - FirstUnboxedTag] = UnboxedType(kind);
unboxedName[kind - FirstUnboxedTag] = Name.fromString(unboxedstr);
boxedSymbol[kind - FirstUnboxedTag] = boxedsym;
}
static void initializeUnboxedTypes(Definitions definitions) {
mkStdClassType(BYTE, "byte", definitions.BYTE_CLASS);
mkStdClassType(SHORT, "short", definitions.SHORT_CLASS);
mkStdClassType(CHAR, "char", definitions.CHAR_CLASS);
mkStdClassType(INT, "int", definitions.INT_CLASS);
mkStdClassType(LONG, "long", definitions.LONG_CLASS);
mkStdClassType(FLOAT, "float", definitions.FLOAT_CLASS);
mkStdClassType(DOUBLE, "double", definitions.DOUBLE_CLASS);
mkStdClassType(BOOLEAN, "boolean", definitions.BOOLEAN_CLASS);
mkStdClassType(UNIT, "void", definitions.UNIT_CLASS);
}
/** Return unboxed type of given kind.
*/
public static Type unboxedType(int kind) {
return unboxedType[kind - FirstUnboxedTag];
}
/** Return the name of unboxed type of given kind.
*/
public static Name unboxedName(int kind) {
return unboxedName[kind - FirstUnboxedTag];
}
/** If type is boxed, return its unboxed equivalent; otherwise return the type
* itself.
*/
public Type unbox() {
switch (this) {
case TypeRef(_, Symbol clasz, Type[] args):
if (args.length == 0) {
for (int i = 0; i < boxedSymbol.length; i++)
if (boxedSymbol[i] == clasz) return unboxedType[i];
} else if (args.length == 1) {
Definitions definitions = Global.instance.definitions;
if (clasz == definitions.ARRAY_CLASS) {
Type item = args[0];
Type bound = item.upperBound();
// todo: check with Philippe if this is what we want.
if (item.symbol().isClass() ||
(bound.symbol() != definitions.ANY_CLASS &&
bound.symbol() != definitions.ANYVAL_CLASS))
{
return UnboxedArrayType(args[0].erasure());
}
}
}
}
return this;
}
//where
private Type upperBound() {
switch (this) {
case TypeRef(Type pre, Symbol sym, Type[] args):
if (sym.kind == TYPE)
return pre.memberInfo(sym).upperBound();
}
return this;
}
/** Return the erasure of this type.
*/
public Type erasure() {
switch (this) {
case ThisType(_):
case SingleType(_, _):
case ConstantType(_, _):
return singleDeref().erasure();
case TypeRef(Type pre, Symbol sym, Type[] args):
switch (sym.kind) {
case ALIAS: case TYPE:
return sym.info().asSeenFrom(pre, sym.owner()).erasure();
case CLASS:
Definitions definitions = Global.instance.definitions;
if (sym == definitions.UNIT_CLASS) return this;
if (sym == definitions.OBJECT_CLASS ||
sym == definitions.ALL_CLASS ||
sym == definitions.ALLREF_CLASS)
return Type.typeRef(NoPrefix, definitions.ANY_CLASS, EMPTY_ARRAY);
else {
Type this1 = unbox();
if (this1 != this) return this1;
else return Type.typeRef(NoPrefix, sym, EMPTY_ARRAY);
}
default: throw new ApplicationError(sym + " has wrong kind: " + sym.kind);
}
case CompoundType(Type[] parents, _):
if (parents.length > 0) return parents[0].erasure();
else return this;
case MethodType(Symbol[] params, Type tp):
Symbol[] params1 = erasureMap.map(params);
Type tp1 = tp.fullErasure();
switch (tp1) {
case MethodType(Symbol[] params2, Type tp2):
Symbol[] newparams = new Symbol[params1.length + params2.length];
System.arraycopy(params1, 0, newparams, 0, params1.length);
System.arraycopy(params2, 0, newparams, params1.length, params2.length);
return MethodType(newparams, tp2);
default:
if (params1 == params && tp1 == tp) return this;
else return MethodType(params1, tp1);
}
case PolyType(_, Type result):
return result.erasure();
default:
return erasureMap.map(this);
}
}
/** Return the full erasure of the type. Full erasure is the same
* as "normal" erasure, except that the "Unit" type is erased to
* the "void" type.
*/
public Type fullErasure() {
Type erasure = erasure();
if (Global.instance.definitions.UNIT_CLASS == erasure.symbol())
erasure = erasure.unbox();
return erasure;
}
// Object Interface -----------------------------------------------------------------
public String toString() {
return new SymbolTablePrinter().printType(this).toString();
}
public String toLongString() {
String str = toString();
if (str.endsWith(".type")) return str + " (with underlying type " + widen() + ")";
else return str;
}
public int hashCode() {
switch (this) {
case ErrorType:
return ERRORtpe;
case NoType:
return NOtpe;
case NoPrefix:
return NOpre;
case ThisType(Symbol sym):
return THIStpe
^ (sym.hashCode() * 41);
case TypeRef(Type pre, Symbol sym, Type[] args):
return TYPEREFtpe
^ (pre.hashCode() * 41)
^ (sym.hashCode() * (41*41))
^ (hashCode(args) * (41*41*41));
case SingleType(Type pre, Symbol sym):
return SINGLEtpe
^ (pre.hashCode() * 41)
^ (sym.hashCode() * (41*41));
case ConstantType(Type base, AConstant value):
return CONSTANTtpe
^ (base.hashCode() * 41)
^ (value.hashCode() * (41*41));
case CompoundType(Type[] parts, Scope members):
return symbol().hashCode();
//return COMPOUNDtpe
// ^ (hashCode(parts) * 41)
// ^ (members.hashCode() * (41 * 41));
case MethodType(Symbol[] vparams, Type result):
int h = METHODtpe;
for (int i = 0; i < vparams.length; i++)
h = (h << 4) ^ (vparams[i].flags & SOURCEFLAGS);
return h
^ (hashCode(Symbol.type(vparams)) * 41)
^ (result.hashCode() * (41 * 41));
case PolyType(Symbol[] tparams, Type result):
return POLYtpe
^ (hashCode(tparams) * 41)
^ (result.hashCode() * (41 * 41));
case OverloadedType(Symbol[] alts, Type[] alttypes):
return OVERLOADEDtpe
^ (hashCode(alts) * 41)
^ (hashCode(alttypes) * (41 * 41));
case UnboxedType(int kind):
return UNBOXEDtpe
^ (kind * 41);
case UnboxedArrayType(Type elemtp):
return UNBOXEDARRAYtpe
^ (elemtp.hashCode() * 41);
default:
throw new ApplicationError("bad type for hashCode: " + this);
}
}
public static int hashCode(Object[] elems) {
int h = 0;
for (int i = 0; i < elems.length; i++)
h = h * 41 + elems[i].hashCode();
return h;
}
// todo: change in relation to needs.
public boolean equals(Object other) {
if (this == other) {
return true;
} else if (other instanceof Type) {
Type that = (Type) other;
switch (this) {
case ErrorType:
return that == ErrorType;
case NoType:
return that == NoType;
case NoPrefix:
return that == NoPrefix;
case ThisType(Symbol sym):
switch (that) {
case ThisType(Symbol sym1):
return sym == sym1;
default: return false;
}
case TypeRef(Type pre, Symbol sym, Type[] args):
switch (that) {
case TypeRef(Type pre1, Symbol sym1, Type[] args1):
return pre.equals(pre1) && sym == sym1 && equals(args, args1);
default: return false;
}
case SingleType(Type pre, Symbol sym):
switch (that) {
case SingleType(Type pre1, Symbol sym1):
return pre.equals(pre1) && sym == sym1;
default: return false;
}
case ConstantType(Type base, AConstant value):
switch (that) {
case ConstantType(Type base1, AConstant value1):
return base.equals(base1) && value.equals(value1);
default: return false;
}
case CompoundType(Type[] parts, Scope members):
switch (that) {
case CompoundType(Type[] parts1, Scope members1):
return this.symbol() == that.symbol();
//return parts.equals(parts1) && members.equals(members1);
default: return false;
}
case MethodType(Symbol[] vparams, Type result):
switch (that) {
case MethodType(Symbol[] vparams1, Type result1):
if (vparams.length != vparams1.length)
return false;
for (int i = 0; i < vparams.length; i++)
if ((vparams[i].flags & SOURCEFLAGS) !=
(vparams1[i].flags & SOURCEFLAGS))
return false;
return
equals(Symbol.type(vparams), Symbol.type(vparams1)) &&
result.equals(result1);
default: return false;
}
case PolyType(Symbol[] tparams, Type result):
switch (that) {
case PolyType(Symbol[] tparams1, Type result1):
return equals(tparams, tparams1) && result.equals(result1);
default: return false;
}
case OverloadedType(Symbol[] alts, Type[] alttypes):
switch (that) {
case OverloadedType(Symbol[] alts1, Type[] alttypes1):
return equals(alts, alts1) && equals(alttypes, alttypes1);
default: return false;
}
case UnboxedType(int kind):
switch (that) {
case UnboxedType(int kind1):
return kind == kind1;
default: return false;
}
case UnboxedArrayType(Type elemtp):
switch (that) {
case UnboxedArrayType(Type elemtp1):
return elemtp.equals(elemtp1);
default: return false;
}
default:
}
}
return false;
}
public static boolean equals(Object[] elems1, Object[] elems2) {
if (elems1.length != elems2.length) return false;
for (int i = 0; i < elems1.length; i++) {
if (!elems1[i].equals(elems2[i])) return false;
}
return true;
}
// Type.List class -----------------------------------------------------------------
/** A class for lists of types.
*/
public static class List {
public Type head;
public List tail;
public List(Type head, List tail) {
this.head = head; this.tail = tail;
}
public int length() {
return (this == EMPTY) ? 0 : 1 + tail.length();
}
public Type[] toArray() {
Type[] ts = new Type[length()];
copyToArray(ts, 0, 1);
return ts;
}
public void copyToArray(Type[] ts, int start, int delta) {
if (this != EMPTY) {
ts[start] = head;
tail.copyToArray(ts, start+delta, delta);
}
}
public Type[] toArrayReverse() {
Type[] ts = new Type[length()];
copyToArray(ts, ts.length - 1, -1);
return ts;
}
public String toString() {
if (this == EMPTY) return "List()";
else return head + "::" + tail;
}
public static List EMPTY = new List(null, null);
public static List append(List l, Type tp) {
return (l == EMPTY) ? new List(tp, EMPTY)
: new List(l.head, append(l.tail, tp));
}
}
// Type.Constraint class -------------------------------------------------------
/** A class for keeping sub/supertype constraints and instantiations
* of type variables.
*/
public static class Constraint {
public List lobounds = List.EMPTY;
public List hibounds = List.EMPTY;
public Type inst = NoType;
public boolean instantiate(Type tp) {
for (List l = lobounds; l != List.EMPTY; l = l.tail) {
if (!l.head.isSubType(tp)) return false;
}
for (List l = hibounds; l != List.EMPTY; l = l.tail) {
if (!tp.isSubType(l.head)) return false;
}
inst = tp;
return true;
}
}
// Type.Error class --------------------------------------------------------------
/** A class for throwing type errors
*/
public static class Error extends java.lang.Error {
public String msg;
public Error(String msg) {
super(msg);
this.msg = msg;
}
}
public static class Malformed extends Error {
public Malformed(Type pre, String tp) {
super("malformed type: " + pre + "#" + tp);
}
}
/** A class for throwing type errors
*/
public static class VarianceError extends Error {
public VarianceError(String msg) {
super(msg);
}
}
public static void explainTypes(Type found, Type required) {
if (Global.instance.explaintypes) {
boolean s = explainSwitch;
explainSwitch = true;
found.isSubType(required);
explainSwitch = s;
}
}
}
/* A standard pattern match:
case ErrorType:
case AnyType:
case NoType:
case ThisType(Symbol sym):
case TypeRef(Type pre, Symbol sym, Type[] args):
case SingleType(Type pre, Symbol sym):
case ConstantType(Type base, Object value):
case CompoundType(Type[] parts, Scope members):
case MethodType(Symbol[] vparams, Type result):
case PolyType(Symbol[] tparams, Type result):
case OverloadedType(Symbol[] alts, Type[] alttypes):
*/