/// <summary>
/// Creates a new BindingTarget when the method binding has succeeded.
/// </summary>
internal BindingTarget(string name, int actualArgumentCount, MethodTarget target, NarrowingLevel level, RestrictionInfo restrictedArgs) {
_name = name;
_target = target;
_restrictedArgs = restrictedArgs;
_level = level;
_actualArgs = actualArgumentCount;
}
public override bool CanConvertFrom(Type fromType, DynamicMetaObject fromArg, ParameterWrapper toParameter, NarrowingLevel level) {
if ((fromType == typeof(List) || fromType.IsSubclassOf(typeof(List)))) {
if (toParameter.Type.IsGenericType() &&
toParameter.Type.GetGenericTypeDefinition() == typeof(IList<>) &&
(toParameter.ParameterInfo.IsDefined(typeof(BytesConversionAttribute), false) ||
toParameter.ParameterInfo.IsDefined(typeof(BytesConversionNoStringAttribute), false))) {
return false;
}
} else if (fromType == typeof(string)) {
if (toParameter.Type == typeof(IList<byte>) &&
!Binder.Context.PythonOptions.Python30 &&
toParameter.ParameterInfo.IsDefined(typeof(BytesConversionAttribute), false)) {
// string -> byte array, we allow this in Python 2.6
return true;
}
} else if (fromType == typeof(Bytes)) {
if (toParameter.Type == typeof(string) &&
!Binder.Context.PythonOptions.Python30 &&
toParameter.ParameterInfo.IsDefined(typeof(BytesConversionAttribute), false)) {
return true;
}
}
return base.CanConvertFrom(fromType, fromArg, toParameter, level);
}
public override bool CanConvertFrom(Type fromType, DynamicMetaObject fromArgument, ParameterWrapper toParameter, NarrowingLevel level)
{
if (toParameter.Type == typeof(string) && (level == NarrowingLevel.Three || level == NarrowingLevel.All))
return true;
if (toParameter.IsParamsArray == true && typeof(IList<object>).IsAssignableFrom(fromType))
{
var toType = toParameter.Type.GetElementType();
var list = (IList<object>)fromArgument.Value;
for(var i = 0; i < list.Count; i++)
{
var itm = list[i];
var argExp = Expression.Call(
Expression.Convert(fromArgument.Expression, fromArgument.LimitType),
(typeof(IList<object>).GetMethod("get_Item")),
Expression.Constant(i, typeof(int))
);
var arg = new DynamicMetaObject(
argExp,
fromArgument.Restrictions,
itm
);
if(!CanConvertFrom(itm.GetType(), arg, new ParameterWrapper(null, toType, null, ParameterBindingFlags.None), level))
return false;
}
return true;
}
return base.CanConvertFrom(fromType, fromArgument, toParameter, level);
}
private readonly int _actualArgs; // gets the actual number of arguments provided
/// <summary>
/// Creates a new BindingTarget when the method binding has succeeded.
/// </summary>
internal BindingTarget(string name, int actualArgumentCount, MethodCandidate candidate, NarrowingLevel level, RestrictedArguments restrictedArgs) {
_name = name;
_candidate = candidate;
_restrictedArgs = restrictedArgs;
_level = level;
_actualArgs = actualArgumentCount;
}
private readonly int _actualArgs; // gets the actual number of arguments provided
/// <summary>
/// Creates a new BindingTarget when the method binding has succeeded.
///
/// OBSOLETE
/// </summary>
internal BindingTarget(string name, int actualArgumentCount, MethodTarget target, NarrowingLevel level, Type[] argTests) {
_name = name;
_target = target;
_argTests = argTests;
_level = level;
_actualArgs = actualArgumentCount;
}
public CallBinderHelper(CodeContext context, TAction action, object[] args, RuleBuilder rule, IList <MethodBase> targets, NarrowingLevel maxLevel, bool isReversedOperator)
: this(context, action, args, rule)
{
_targets = ArrayUtils.ToArray(targets);
_reversedOperator = isReversedOperator;
_maxLevel = maxLevel;
}
public bool HasConversionFrom(Type ty, NarrowingLevel allowNarrowing)
{
if (ty == Type)
{
return(true);
}
if (ty == None.Type)
{
if (_prohibitNull)
{
return(false);
}
if (Type.IsGenericType && Type.GetGenericTypeDefinition() == typeof(Nullable <>))
{
return(true);
}
return(!Type.IsValueType);
}
else
{
return(_binder.CanConvertFrom(ty, Type, allowNarrowing));
}
}
/// <summary>
/// Performs binding against a set of overloaded methods using the specified arguments. The arguments are
/// consumed as specified by the CallSignature object.
/// </summary>
/// <param name="minLevel">TODO.</param>
/// <param name="maxLevel">TODO.</param>
/// <param name="resolver">Overload resolver.</param>
/// <param name="targets">The methods to be called</param>
/// <param name="restrictions">Additional restrictions which should be applied to the resulting MetaObject.</param>
/// <param name="target">The resulting binding target which can be used for producing error information.</param>
/// <param name="name">The name of the method or null to use the name from targets.</param>
/// <returns>A meta object which results from the call.</returns>
public DynamicMetaObject CallMethod(DefaultOverloadResolver resolver, IList <MethodBase> targets, BindingRestrictions restrictions, string name,
NarrowingLevel minLevel, NarrowingLevel maxLevel, out BindingTarget target)
{
ContractUtils.RequiresNotNull(resolver, nameof(resolver));
ContractUtils.RequiresNotNullItems(targets, nameof(targets));
ContractUtils.RequiresNotNull(restrictions, nameof(restrictions));
// attempt to bind to an individual method
target = resolver.ResolveOverload(name ?? GetTargetName(targets), targets, minLevel, maxLevel);
if (target.Success)
{
// if we succeed make the target for the rule
return(new DynamicMetaObject(
target.MakeExpression(),
restrictions.Merge(
MakeSplatTests(resolver.CallType, resolver.Signature, resolver.Arguments).
Merge(target.RestrictedArguments.GetAllRestrictions())
)
));
}
// make an error rule
return(MakeInvalidParametersRule(resolver, restrictions, target));
}
private readonly int _actualArgs; // gets the actual number of arguments provided
/// <summary>
/// Creates a new BindingTarget when the method binding has succeeded.
/// </summary>
internal BindingTarget(string name, int actualArgumentCount, MethodCandidate candidate, NarrowingLevel level, RestrictedArguments restrictedArgs)
{
_name = name;
_candidate = candidate;
_restrictedArgs = restrictedArgs;
_level = level;
_actualArgs = actualArgumentCount;
}
/// <summary>
/// Creates a new BindingTarget when the method binding has succeeded
/// </summary>
internal BindingTarget(string name, int actualArgumentCount, MethodTarget target, NarrowingLevel level, MetaObject[] restrictedArgs)
{
_name = name;
_target = target;
_restrictedArgs = restrictedArgs;
_level = level;
_actualArgs = actualArgumentCount;
}
private readonly int _actualArgs; // gets the actual number of arguments provided
/// <summary>
/// Creates a new BindingTarget when the method binding has succeeded
/// </summary>
internal BindingTarget(string name, int actualArgumentCount, MethodTarget target, NarrowingLevel level, Type[] argTests)
{
_name = name;
_target = target;
_argTests = argTests;
_level = level;
_actualArgs = actualArgumentCount;
}
private readonly int[] _expectedArgs; // gets the acceptable number of parameters which can be passed to the method.
/// <summary>
/// Creates a new BindingTarget when the method binding has succeeded.
/// </summary>
internal BindingTarget(string name, int actualArgumentCount, MethodCandidate candidate, NarrowingLevel level, RestrictedArguments restrictedArgs)
{
Name = name;
MethodCandidate = candidate;
RestrictedArguments = restrictedArgs;
NarrowingLevel = level;
ActualArgumentCount = actualArgumentCount;
}
public bool IsApplicable(Type[] types, SymbolId[] names, NarrowingLevel allowNarrowing)
{
if (!TryGetNormalizedArguments(types, names, out types))
{
return(false);
}
return(IsApplicable(types, allowNarrowing));
}
internal MethodCandidate(MethodTarget target, List <ParameterWrapper> parameters)
{
Debug.Assert(target != null);
_target = target;
_parameters = parameters;
_narrowingLevel = NarrowingLevel.None;
parameters.TrimExcess();
}
public override bool CanConvertFrom(Type fromType, DynamicMetaObject fromArgument, ParameterWrapper toParameter, NarrowingLevel level)
{
if (level >= NarrowingLevel.Two)
{
if (toParameter.Type == typeof(string))
return true;
}
return base.CanConvertFrom(fromType, fromArgument, toParameter, level);
}
private readonly NarrowingLevel _maxLevel; // the maximum narrowing level allowed
public CallBinderHelper(CodeContext context, TAction action, object[] args, RuleBuilder rule)
: base(context, action)
{
ContractUtils.RequiresNotEmpty(args, "args");
_maxLevel = NarrowingLevel.All;
_args = RemoveExplicitInstanceArgument(action, args);
_rule = rule;
_test = _rule.MakeTypeTest(CompilerHelpers.GetType(Callable), 0);
}
public override bool CanConvertFrom(Type fromType, ParameterWrapper toParameter, NarrowingLevel level) {
if ((fromType == typeof(List) || fromType.IsSubclassOf(typeof(List))) &&
toParameter.Type.IsGenericType &&
toParameter.Type.GetGenericTypeDefinition() == typeof(IList<>)) {
if (toParameter.ParameterInfo.IsDefined(typeof(ProhibitGenericListConversionAttribute), false)) {
return false;
}
}
return base.CanConvertFrom(fromType, toParameter, level);
}
private List <MethodCandidate> SelectTargets(CallType callType, Type[] types, SymbolId[] names)
{
// obsolete: this should be removed entirely:
if (!_binder.StrictParameterCheck)
{
if (_targets.Count == 1 && !_binder.IsBinaryOperator && names.Length == 0)
{
return(_targets);
}
}
List <MethodCandidate> applicableTargets = new List <MethodCandidate>();
foreach (MethodCandidate target in _targets)
{
if (target.IsApplicable(types, names, NarrowingLevel.None))
{
applicableTargets.Add(target);
}
}
List <MethodCandidate> result = null;
if (TryGetApplicableTarget(callType, applicableTargets, types, out result))
{
return(result);
}
//no targets are applicable without narrowing conversions, so try those
foreach (MethodCandidate target in _targets)
{
if (target.IsApplicable(types, names, NarrowingLevel.Preferred))
{
applicableTargets.Add(new MethodCandidate(target, NarrowingLevel.Preferred));
}
}
if (TryGetApplicableTarget(callType, applicableTargets, types, out result))
{
return(result);
}
foreach (MethodCandidate target in _targets)
{
NarrowingLevel nl = _binder.IsBinaryOperator ? NarrowingLevel.Operator : NarrowingLevel.All;
if (target.IsApplicable(types, names, nl))
{
applicableTargets.Add(new MethodCandidate(target, nl));
}
}
return(applicableTargets);
}
/// <summary>
/// Performs binding against a set of overloaded methods using the specified arguments. All arguments
/// are treated as positional arguments.
/// </summary>
/// <param name="parameterBinder">ParameterBinder used to map arguments to parameters.</param>
/// <param name="targets">The methods to be called</param>
/// <param name="args">The arguments for the call</param>
/// <param name="maxLevel">The maximum narrowing level for arguments. The current narrowing level is flowed thorugh to the DefaultBinder.</param>
/// <param name="minLevel">The minimum narrowing level for the arguments. The current narrowing level is flowed thorugh to the DefaultBinder.</param>
/// <returns>A meta object which results from the call.</returns>
public DynamicMetaObject CallMethod(ParameterBinder parameterBinder, IList<MethodBase> targets, IList<DynamicMetaObject> args, NarrowingLevel minLevel, NarrowingLevel maxLevel) {
return CallWorker(
parameterBinder,
targets,
args,
new CallSignature(args.Count),
CallTypes.None,
BindingRestrictions.Empty,
minLevel,
maxLevel,
null
);
}
public bool IsApplicable(Type[] types, NarrowingLevel allowNarrowing)
{
Debug.Assert(types.Length == _parameters.Count);
for (int i = 0; i < types.Length; i++)
{
if (!_parameters[i].HasConversionFrom(types[i], allowNarrowing))
{
return(false);
}
}
return(true);
}
internal bool IsApplicable(Type[] types, NarrowingLevel narrowingLevel, List <ConversionResult> conversionResults)
{
// attempt to convert each parameter
bool res = true;
for (int i = 0; i < types.Length; i++)
{
bool success = _parameters[i].HasConversionFrom(types[i], narrowingLevel);
conversionResults.Add(new ConversionResult(types[i], _parameters[i].Type, i, !success));
res &= success;
}
return(res);
}
private static Candidate GetPreferredParameter(ParameterWrapper candidateOne, ParameterWrapper candidateTwo, MetaObject actualType)
{
Assert.NotNull(candidateOne, candidateTwo, actualType);
if (candidateOne._binder.ParametersEquivalent(candidateOne, candidateTwo))
{
return(Candidate.Equivalent);
}
for (NarrowingLevel curLevel = NarrowingLevel.None; curLevel <= NarrowingLevel.All; curLevel++)
{
Candidate candidate = candidateOne._binder.SelectBestConversionFor(actualType.LimitType, candidateOne, candidateTwo, curLevel);
if (candidate.Chosen())
{
return(candidate);
}
}
return(GetPreferredParameter(candidateOne, candidateTwo));
}
internal bool IsApplicable(MetaObject[] objects, NarrowingLevel narrowingLevel, List <ConversionResult> conversionResults)
{
// attempt to convert each parameter
bool res = true;
for (int i = 0; i < objects.Length; i++)
{
/*if (objects[i].NeedsDeferral) {
* conversionResults.Add(new ConversionResult(typeof(Dynamic), _parameters[i].Type, i, false));
* } else*/{
bool success = _parameters[i].HasConversionFrom(objects[i].LimitType, narrowingLevel);
conversionResults.Add(new ConversionResult(objects[i].LimitType, _parameters[i].Type, i, !success));
res &= success;
}
}
return(res);
}
public bool IsApplicable(Type[] types, SymbolId[] names, NarrowingLevel allowNarrowing)
{
#if FULL
foreach (ParameterWrapper pw in _parameters)
{
// can't bind to methods that are params dictionaries, only to their extended forms.
if (pw.IsParamsDict)
{
return(false);
}
}
#endif
if (!TryGetNormalizedArguments(types, names, out types))
{
return(false);
}
return(IsApplicable(types, allowNarrowing));
}
internal static ConversionResultKind?ToConversionResultKind(this NarrowingLevel narrowingLevel)
{
switch (narrowingLevel)
{
case NarrowingLevel.None:
return(null);
case NarrowingLevel.One:
return(ConversionResultKind.ImplicitCast);
case NarrowingLevel.Two:
return(ConversionResultKind.ImplicitTry);
case NarrowingLevel.Three:
return(ConversionResultKind.ExplicitCast);
case NarrowingLevel.All:
default:
return(ConversionResultKind.ExplicitTry);
}
}
public override bool CanConvertFrom(Type fromType, Type toType, NarrowingLevel level)
{
if (fromType == toType || toType.IsAssignableFrom(fromType))
{
return(true);
}
if (toType == typeof(object) || toType == fromType)
{
return(true);
}
if (fromType == typeof(int) && toType == typeof(double))
{
return(true);
}
if (fromType == typeof(SymbolId) && toType.IsEnum)
{
return(true);
}
if (fromType == typeof(object) && level == NarrowingLevel.All)
{
return(true);
}
return(false);
}
public override bool CanConvertFrom(Type fromType, Type toType, NarrowingLevel level)
{
if (fromType == toType || toType.IsAssignableFrom(fromType))
{
return true;
}
if (toType == typeof(object) || toType == fromType)
{
return true;
}
if (fromType == typeof(int) && toType == typeof(double))
{
return true;
}
if (fromType == typeof(SymbolId) && toType.IsEnum)
{
return true;
}
if (fromType == typeof(object) && level == NarrowingLevel.All)
{
return true;
}
return false;
}
public override Candidate SelectBestConversionFor(Type /*!*/ actualType, ParameterWrapper /*!*/ candidateOne, ParameterWrapper /*!*/ candidateTwo, NarrowingLevel level)
{
Type typeOne = candidateOne.Type;
Type typeTwo = candidateTwo.Type;
if (actualType == typeof(Null))
{
// if nil is passed as a block argument prefer BlockParam over missing block;
if (typeOne == typeof(BlockParam) && typeTwo == typeof(MissingBlockParam))
{
return(Candidate.One);
}
if (typeOne == typeof(MissingBlockParam) && typeTwo == typeof(BlockParam))
{
return(Candidate.Two);
}
}
else
{
if (actualType == typeOne && candidateOne.ProhibitNull)
{
return(Candidate.One);
}
if (actualType == typeTwo && candidateTwo.ProhibitNull)
{
return(Candidate.Two);
}
}
if (actualType == typeOne)
{
return(Candidate.One);
}
if (actualType == typeTwo)
{
return(Candidate.Two);
}
return(Candidate.Equivalent);
}
public override bool CanConvertFrom(Type/*!*/ fromType, Type/*!*/ toType, bool toNotNullable, NarrowingLevel level) {
return Converter.CanConvertFrom(null, fromType, toType, toNotNullable, level, false, false);
}
private Candidate GetPreferredParameter(ParameterWrapper candidateOne, ParameterWrapper candidateTwo, DynamicMetaObject arg, NarrowingLevel level) {
Assert.NotNull(candidateOne, candidateTwo);
if (ParametersEquivalent(candidateOne, candidateTwo)) {
return Candidate.Equivalent;
}
Candidate candidate = SelectBestConversionFor(arg, candidateOne, candidateTwo, level);
if (candidate.Chosen()) {
return candidate;
}
if (CanConvertFrom(candidateTwo, candidateOne)) {
if (CanConvertFrom(candidateOne, candidateTwo)) {
return Candidate.Ambiguous;
} else {
return Candidate.Two;
}
} else if (CanConvertFrom(candidateOne, candidateTwo)) {
return Candidate.One;
}
// Special additional rules to order numeric value types
Type t1 = candidateOne.Type;
Type t2 = candidateTwo.Type;
Candidate preferred = PreferConvert(t1, t2);
if (preferred.Chosen()) {
return preferred;
}
preferred = PreferConvert(t2, t1).TheOther();
if (preferred.Chosen()) {
return preferred;
}
// consider the actual argument type:
Type argType = arg.GetLimitType();
NarrowingLevel levelOne = NarrowingLevel.None;
while (levelOne < level && !CanConvertFrom(argType, arg, candidateOne, levelOne)) {
if (levelOne == NarrowingLevel.All) {
Debug.Assert(false, "Each argument should be convertible to the corresponding parameter");
break;
}
levelOne++;
}
NarrowingLevel levelTwo = NarrowingLevel.None;
while (levelTwo < level && !CanConvertFrom(argType, arg, candidateTwo, levelTwo)) {
if (levelTwo == NarrowingLevel.All) {
Debug.Assert(false, "Each argument should be convertible to the corresponding parameter");
break;
}
levelTwo++;
}
if (levelOne < levelTwo) {
return Candidate.One;
} else if (levelOne > levelTwo) {
return Candidate.Two;
} else {
return Candidate.Ambiguous;
}
}
private int? SelectBestConversionFor(Type actualType, Type candidateOne, Type candidateTwo, NarrowingLevel level) {
Type ret = _binder.SelectBestConversionFor(actualType, candidateOne, candidateTwo, level);
if (ret != null) {
if (ret == candidateOne) {
return +1;
} else if (ret == candidateTwo) {
return -1;
}
}
return null;
}
public override Candidate SelectBestConversionFor(DynamicMetaObject /*!*/ arg, ParameterWrapper /*!*/ candidateOne,
ParameterWrapper /*!*/ candidateTwo, NarrowingLevel level)
{
Type typeOne = candidateOne.Type;
Type typeTwo = candidateTwo.Type;
Type actualType = arg.GetLimitType();
if (actualType == typeof(DynamicNull))
{
// if nil is passed as a block argument prefers BlockParam over a missing block:
if (typeOne == typeof(BlockParam) && typeTwo == typeof(MissingBlockParam))
{
Debug.Assert(!candidateOne.ProhibitNull);
return(Candidate.One);
}
if (typeOne == typeof(MissingBlockParam) && typeTwo == typeof(BlockParam))
{
Debug.Assert(!candidateTwo.ProhibitNull);
return(Candidate.Two);
}
}
else
{
if (typeOne == actualType)
{
if (typeTwo == actualType)
{
// prefer non-nullable reference type over nullable:
if (!actualType.IsValueType)
{
if (candidateOne.ProhibitNull)
{
return(Candidate.One);
}
else if (candidateTwo.ProhibitNull)
{
return(Candidate.Two);
}
}
}
else
{
return(Candidate.One);
}
}
else if (typeTwo == actualType)
{
return(Candidate.Two);
}
}
// prefer integer type over enum:
if (typeOne.IsEnum && Enum.GetUnderlyingType(typeOne) == typeTwo)
{
return(Candidate.Two);
}
if (typeTwo.IsEnum && Enum.GetUnderlyingType(typeTwo) == typeOne)
{
return(Candidate.One);
}
return(base.SelectBestConversionFor(arg, candidateOne, candidateTwo, level));
}
public override bool CanConvertFrom(Type /*!*/ fromType, Type /*!*/ toType, bool toNotNullable, NarrowingLevel level)
{
return(Converter.CanConvertFrom(null, fromType, toType, toNotNullable, level, false, false).IsConvertible);
}
internal static bool CanConvertFrom(Type fromType, Type toType, NarrowingLevel level)
{
ContractUtils.RequiresNotNull(fromType, "fromType");
ContractUtils.RequiresNotNull(toType, "toType");
// NarrowingLevel.Zero
if (fromType == toType)
{
return(true);
}
// I don't want to consider boxing before numeric conversion, else I don't get the convert-int-to-long behavior required to select Numbers.lt(long,long) over Numbers.lt(long,Object)
// We also need to get the narrow-long-to-int behavior required to avoid casting in host expression calls.
// IronRuby and IronPython both do this here:
//if (toType.IsAssignableFrom(fromType))
//{
// return true;
//}
// Because long[] and ulong[] are inter-assignable, we run into problems.
// Let's just not convert from an array of one primitive type to another.
if (fromType.IsArray && toType.IsArray && (Util.IsPrimitiveNumeric(fromType.GetElementType()) || Util.IsPrimitiveNumeric(toType.GetElementType())))
{
return(false);
}
if (!Util.IsPrimitiveNumeric(fromType) && toType.IsAssignableFrom(fromType))
{
return(true);
}
if (fromType.IsCOMObject && toType.IsInterface)
{
return(true); // A COM object could be cast to any interface
}
if (HasImplicitNumericConversion(fromType, toType))
{
return(true);
}
// try available type conversions...
object[] tcas = toType.GetCustomAttributes(typeof(TypeConverterAttribute), true);
foreach (TypeConverterAttribute tca in tcas)
{
TypeConverter tc = GetTypeConverter(tca);
if (tc == null)
{
continue;
}
if (tc.CanConvertFrom(fromType))
{
return(true);
}
}
//!!!do user-defined implicit conversions here
if (level == NarrowingLevel.None)
{
return(false);
}
// NarrowingLevel.One
if (WideningIntegerConversion(fromType, toType))
{
return(true);
}
if (level == NarrowingLevel.One)
{
return(false);
}
// NarrowingLevel.Two
if (SpecialClojureConversion(fromType, toType))
{
return(true);
}
if (DelegateType.IsAssignableFrom(toType) && typeof(IFn).IsAssignableFrom(fromType))
{
return(true);
}
if (level == NarrowingLevel.Two)
{
return(false);
}
// NarrowingLevel.Three
if (toType == typeof(bool))
{
return(true);
}
if (Util.IsPrimitiveNumeric(toType) && Util.IsPrimitiveNumeric(fromType))
{
return(true);
}
// Handle conversions of IEnumerable<Object> or IEnumerable to IEnumerable<T> for any T
// Similar to code in IPy's IronPython.Runtime.Converter.HasNarrowingConversion
if (toType.IsGenericType)
{
Type genTo = toType.GetGenericTypeDefinition();
if (genTo == typeof(IEnumerable <>))
{
return(typeof(IEnumerable <Object>).IsAssignableFrom(fromType) || typeof(IEnumerable).IsAssignableFrom(fromType));
}
}
if (level == NarrowingLevel.Three)
{
return(false);
}
// NarrowingLevel.All
if (level < NarrowingLevel.All)
{
return(false);
}
// pick up boxing numerics here
if (toType.IsAssignableFrom(fromType))
{
return(true);
}
// TODO: Rethink. IPy has the following, but we get overload problems on Numbers ops
//return HasNarrowingConversion(fromType, toType, level);
// Handle conversions of IEnumerable<Object> or IEnumerable to IEnumerable<T> for any T
// Similar to code in IPy's IronPython.Runtime.Converter.HasNarrowingConversion
if (toType.IsGenericType)
{
Type genTo = toType.GetGenericTypeDefinition();
if (genTo == typeof(IList <>))
{
return(typeof(IList <object>).IsAssignableFrom(fromType));
}
else if (genTo == typeof(Nullable <>))
{
if (fromType == typeof(DynamicNull) || CanConvertFrom(fromType, toType.GetGenericArguments()[0], level))
{
return(true);
}
}
else if (genTo == typeof(IDictionary <,>))
{
return(typeof(IDictionary <object, object>).IsAssignableFrom(fromType));
}
}
return(false);
}
private static bool HasNarrowingConversion(Type fromType, Type toType, NarrowingLevel allowNarrowing)
{
if (allowNarrowing == PythonNarrowing.IndexOperator)
{
if (toType == CharType && fromType == StringType)
{
return(true);
}
if (toType == StringType && fromType == CharType)
{
return(true);
}
//if (toType == Int32Type && fromType == BigIntegerType) return true;
//if (IsIntegral(fromType) && IsIntegral(toType)) return true;
//Check if there is an implicit convertor defined on fromType to toType
if (HasImplicitConversion(fromType, toType))
{
return(true);
}
}
if (toType == DoubleType && fromType == DecimalType)
{
return(true);
}
if (toType == SingleType && fromType == DecimalType)
{
return(true);
}
if (toType.IsArray)
{
return(typeof(PythonTuple).IsAssignableFrom(fromType));
}
if (allowNarrowing == PythonNarrowing.IndexOperator)
{
if (IsNumeric(fromType) && IsNumeric(toType))
{
if (fromType != typeof(float) && fromType != typeof(double) && fromType != typeof(decimal) && fromType != typeof(Complex))
{
return(true);
}
}
if (fromType == typeof(bool) && IsNumeric(toType))
{
return(true);
}
if (toType == CharType && fromType == StringType)
{
return(true);
}
if (toType == Int32Type && fromType == BooleanType)
{
return(true);
}
// Everything can convert to Boolean in Python
if (toType == BooleanType)
{
return(true);
}
if (DelegateType.IsAssignableFrom(toType) && IsPythonType(fromType))
{
return(true);
}
if (IEnumerableType == toType && IsPythonType(fromType))
{
return(true);
}
if (toType == typeof(IEnumerator))
{
if (IsPythonType(fromType))
{
return(true);
}
}
else if (toType.IsGenericType())
{
Type genTo = toType.GetGenericTypeDefinition();
if (genTo == IEnumerableOfTType)
{
return(IEnumerableOfObjectType.IsAssignableFrom(fromType) ||
IEnumerableType.IsAssignableFrom(fromType) ||
fromType == typeof(OldInstance));
}
else if (genTo == typeof(System.Collections.Generic.IEnumerator <>))
{
if (IsPythonType(fromType))
{
return(true);
}
}
}
}
if (allowNarrowing == PythonNarrowing.All)
{
//__int__, __float__, __long__
if (IsNumeric(fromType) && IsNumeric(toType))
{
return(true);
}
if (toType == Int32Type && HasPythonProtocol(fromType, "__int__"))
{
return(true);
}
if (toType == DoubleType && HasPythonProtocol(fromType, "__float__"))
{
return(true);
}
if (toType == BigIntegerType && HasPythonProtocol(fromType, "__long__"))
{
return(true);
}
}
if (toType.IsGenericType())
{
Type genTo = toType.GetGenericTypeDefinition();
if (genTo == IListOfTType)
{
return(IListOfObjectType.IsAssignableFrom(fromType));
}
else if (genTo == NullableOfTType)
{
if (fromType == typeof(DynamicNull) || CanConvertFrom(fromType, toType.GetGenericArguments()[0], allowNarrowing))
{
return(true);
}
}
else if (genTo == IDictOfTType)
{
return(IDictionaryOfObjectType.IsAssignableFrom(fromType));
}
}
if (fromType == BigIntegerType && toType == Int64Type)
{
return(true);
}
if (toType.IsEnum() && fromType == Enum.GetUnderlyingType(toType))
{
return(true);
}
return(false);
}
public override bool CanConvertFrom(Type fromType, Type toType, bool toNotNullable, NarrowingLevel level)
{
return(toType.IsAssignableFrom(fromType));
}
internal static bool CanConvertFrom(DynamicMetaObject fromArg, Type/*!*/ fromType, Type/*!*/ toType, bool toNotNullable,
NarrowingLevel level, bool explicitProtocolConversions, bool implicitProtocolConversions) {
ContractUtils.RequiresNotNull(fromType, "fromType");
ContractUtils.RequiresNotNull(toType, "toType");
var metaConvertible = fromArg as IConvertibleMetaObject;
//
// narrowing level 0:
//
if (toType == fromType) {
return true;
}
if (fromType == typeof(DynamicNull)) {
if (toNotNullable) {
return false;
}
if (toType.IsGenericType && toType.GetGenericTypeDefinition() == typeof(Nullable<>)) {
return true;
}
if (!toType.IsValueType) {
// null convertible to any reference type:
return true;
} else if (toType == typeof(bool)) {
return true;
} else if (!ProtocolConversionAction.HasDefaultConversion(toType)) {
// null not convertible to a value type unless a protocol conversion is allowed:
return false;
}
}
// blocks:
if (fromType == typeof(MissingBlockParam)) {
return toType == typeof(BlockParam) && !toNotNullable;
}
if (fromType == typeof(BlockParam) && toType == typeof(MissingBlockParam)) {
return true;
}
if (toType.IsAssignableFrom(fromType)) {
return true;
}
// A COM object could be cast to any interface:
if (Utils.IsComObjectType(fromType) && toType.IsInterface) {
return true;
}
if (HasImplicitNumericConversion(fromType, toType)) {
return true;
}
if (CompilerHelpers.GetImplicitConverter(fromType, toType) != null) {
return true;
}
if (metaConvertible != null) {
return metaConvertible.CanConvertTo(toType, false);
}
//
// narrowing level 1:
//
if (level < NarrowingLevel.One) {
return false;
}
if (explicitProtocolConversions && ProtocolConversionAction.HasDefaultConversion(toType)) {
return true;
}
//
// narrowing level 2:
//
if (level < NarrowingLevel.Two) {
return false;
}
if (HasExplicitNumericConversion(fromType, toType)) {
return true;
}
if (CompilerHelpers.GetExplicitConverter(fromType, toType) != null) {
return true;
}
if (CompilerHelpers.HasTypeConverter(fromType, toType)) {
return true;
}
if (fromType == typeof(char) && toType == typeof(string)) {
return true;
}
if (toType == typeof(bool)) {
return true;
}
if (metaConvertible != null) {
return metaConvertible.CanConvertTo(toType, true);
}
//
// narrowing level 3:
//
if (level < NarrowingLevel.Three) {
return false;
}
if (implicitProtocolConversions && ProtocolConversionAction.HasDefaultConversion(toType)) {
return true;
}
return false;
}
internal static bool CanConvertFrom(Type fromType, Type toType, NarrowingLevel level)
{
ContractUtils.RequiresNotNull(fromType, "fromType");
ContractUtils.RequiresNotNull(toType, "toType");
// NarrowingLevel.Zero
if (fromType == toType)
return true;
// I don't want to consider boxing before numeric conversion, else I don't get the convert-int-to-long behavior required to select Numbers.lt(long,long) over Numbers.lt(long,Object)
// We also need to get the narrow-long-to-int behavior required to avoid casting in host expression calls.
// IronRuby and IronPython both do this here:
//if (toType.IsAssignableFrom(fromType))
//{
// return true;
//}
// Because long[] and ulong[] are inter-assignable, we run into problems.
// Let's just not convert from an array of one primitive type to another.
if (fromType.IsArray && toType.IsArray && (Util.IsPrimitiveNumeric(fromType.GetElementType()) || Util.IsPrimitiveNumeric(toType.GetElementType())))
{
return false;
}
if (!Util.IsPrimitiveNumeric(fromType) && toType.IsAssignableFrom(fromType))
{
return true;
}
if (fromType.IsCOMObject && toType.IsInterface)
return true; // A COM object could be cast to any interface
if (HasImplicitNumericConversion(fromType, toType))
return true;
// try available type conversions...
object[] tcas = toType.GetCustomAttributes(typeof(TypeConverterAttribute), true);
foreach (TypeConverterAttribute tca in tcas)
{
TypeConverter tc = GetTypeConverter(tca);
if (tc == null) continue;
if (tc.CanConvertFrom(fromType))
{
return true;
}
}
//!!!do user-defined implicit conversions here
if (level == NarrowingLevel.None)
return false;
// NarrowingLevel.One
if (WideningIntegerConversion(fromType, toType))
{
return true;
}
if (level == NarrowingLevel.One)
return false;
// NarrowingLevel.Two
if (SpecialClojureConversion(fromType, toType))
{
return true;
}
if (DelegateType.IsAssignableFrom(toType) && typeof(IFn).IsAssignableFrom(fromType))
return true;
if (level == NarrowingLevel.Two)
return false;
// NarrowingLevel.Three
if (toType == typeof(bool))
{
return true;
}
if (Util.IsPrimitiveNumeric(toType) && Util.IsPrimitiveNumeric(fromType))
{
return true;
}
// Handle conversions of IEnumerable<Object> or IEnumerable to IEnumerable<T> for any T
// Similar to code in IPy's IronPython.Runtime.Converter.HasNarrowingConversion
if (toType.IsGenericType)
{
Type genTo = toType.GetGenericTypeDefinition();
if (genTo == typeof(IEnumerable<>))
return typeof(IEnumerable<Object>).IsAssignableFrom(fromType) || typeof(IEnumerable).IsAssignableFrom(fromType);
}
if (level == NarrowingLevel.Three)
return false;
// NarrowingLevel.All
if (level < NarrowingLevel.All)
{
return false;
}
// pick up boxing numerics here
if (toType.IsAssignableFrom(fromType))
{
return true;
}
// TODO: Rethink. IPy has the following, but we get overload problems on Numbers ops
//return HasNarrowingConversion(fromType, toType, level);
// Handle conversions of IEnumerable<Object> or IEnumerable to IEnumerable<T> for any T
// Similar to code in IPy's IronPython.Runtime.Converter.HasNarrowingConversion
if (toType.IsGenericType)
{
Type genTo = toType.GetGenericTypeDefinition();
if (genTo == typeof(IList<>) )
{
return typeof(IList<object>).IsAssignableFrom(fromType);
}
else if (genTo == typeof(Nullable<>))
{
if (fromType == typeof(DynamicNull) || CanConvertFrom(fromType, toType.GetGenericArguments()[0], level))
{
return true;
}
}
else if (genTo == typeof(IDictionary<,>) )
{
return typeof(IDictionary<object,object>).IsAssignableFrom(fromType);
}
}
return false;
}
private BindingTarget MakeSuccessfulBindingTarget(ApplicableCandidate result, List<ApplicableCandidate> potentialCandidates,
NarrowingLevel level, CandidateSet targetSet) {
return new BindingTarget(
_methodName,
_actualArguments.VisibleCount,
result.Method,
level,
GetRestrictedArgs(result, potentialCandidates, targetSet.Arity)
);
}
private ApplicableCandidate SelectBestCandidate(List<ApplicableCandidate> candidates, NarrowingLevel level) {
foreach (var candidate in candidates) {
if (IsBest(candidate, candidates, level)) {
return candidate;
}
}
return null;
}
/// <summary>
/// Returns true if fromArg of type fromType can be assigned to toParameter with a conversion on given narrowing level.
/// </summary>
public override bool CanConvertFrom(Type /*!*/ fromType, DynamicMetaObject fromArg, ParameterWrapper /*!*/ toParameter, NarrowingLevel level)
{
return(Converter.CanConvertFrom(fromArg, fromType, toParameter.Type, toParameter.ProhibitNull, level,
HasExplicitProtocolConversion(toParameter), _implicitProtocolConversions
));
}
public override bool CanConvertFrom(Type fromType, Type toType, NarrowingLevel level)
{
return toType.IsAssignableFrom(fromType);
}
public static bool CanConvertFrom(Type fromType, Type toType, NarrowingLevel allowNarrowing)
{
ContractUtils.RequiresNotNull(fromType, "fromType");
ContractUtils.RequiresNotNull(toType, "toType");
if (toType == fromType)
{
return(true);
}
if (toType.IsAssignableFrom(fromType))
{
return(true);
}
#if FEATURE_COM
if (fromType.IsCOMObject && toType.IsInterface)
{
return(true); // A COM object could be cast to any interface
}
#endif
if (HasImplicitNumericConversion(fromType, toType))
{
return(true);
}
// Handling the hole that Type is the only object that we 'box'
if (toType == TypeType &&
(typeof(PythonType).IsAssignableFrom(fromType) ||
typeof(TypeGroup).IsAssignableFrom(fromType)))
{
return(true);
}
// Support extensible types with simple implicit conversions to their base types
if (typeof(Extensible <int>).IsAssignableFrom(fromType) && CanConvertFrom(Int32Type, toType, allowNarrowing))
{
return(true);
}
if (typeof(Extensible <BigInteger>).IsAssignableFrom(fromType) && CanConvertFrom(BigIntegerType, toType, allowNarrowing))
{
return(true);
}
if (typeof(ExtensibleString).IsAssignableFrom(fromType) && CanConvertFrom(StringType, toType, allowNarrowing))
{
return(true);
}
if (typeof(Extensible <double>).IsAssignableFrom(fromType) && CanConvertFrom(DoubleType, toType, allowNarrowing))
{
return(true);
}
if (typeof(Extensible <Complex>).IsAssignableFrom(fromType) && CanConvertFrom(ComplexType, toType, allowNarrowing))
{
return(true);
}
#if FEATURE_CUSTOM_TYPE_DESCRIPTOR
// try available type conversions...
object[] tcas = toType.GetCustomAttributes(typeof(TypeConverterAttribute), true);
foreach (TypeConverterAttribute tca in tcas)
{
TypeConverter tc = GetTypeConverter(tca);
if (tc == null)
{
continue;
}
if (tc.CanConvertFrom(fromType))
{
return(true);
}
}
#endif
//!!!do user-defined implicit conversions here
if (allowNarrowing == PythonNarrowing.None)
{
return(false);
}
return(HasNarrowingConversion(fromType, toType, allowNarrowing));
}
/// <summary> /// Determines if a conversion exists from fromType to toType at the specified narrowing level. /// toNotNullable is true if the target variable doesn't allow null values. /// </summary> public abstract bool CanConvertFrom(Type fromType, Type toType, bool toNotNullable, NarrowingLevel level);
private int?SelectBestConversionFor(Type actualType, Type candidateOne, Type candidateTwo, NarrowingLevel level)
{
Type ret = _binder.SelectBestConversionFor(actualType, candidateOne, candidateTwo, level);
if (ret != null)
{
if (ret == candidateOne)
{
return(+1);
}
else if (ret == candidateTwo)
{
return(-1);
}
}
return(null);
}
/// <summary>
/// Returns true if fromArg of type fromType can be assigned to toParameter with a conversion on given narrowing level.
/// </summary>
public override bool CanConvertFrom(Type/*!*/ fromType, DynamicMetaObject fromArg, ParameterWrapper/*!*/ toParameter, NarrowingLevel level) {
var result = Converter.CanConvertFrom(fromArg, fromType, toParameter.Type, toParameter.ProhibitNull, level,
HasExplicitProtocolConversion(toParameter), _implicitProtocolConversions
);
if (result.Assumption != null) {
if (_argumentAssumptions == null) {
_argumentAssumptions = new List<Key<int, NarrowingLevel, Ast>>();
}
if (_argumentAssumptions.FindIndex((k) => k.First == toParameter.ParameterInfo.Position && k.Second == level) < 0) {
_argumentAssumptions.Add(Key.Create(toParameter.ParameterInfo.Position, level, result.Assumption));
}
}
return result.IsConvertible;
}
/// <summary>
/// Returns true if fromArg of type fromType can be assigned to toParameter with a conversion on given narrowing level.
/// </summary>
public override bool CanConvertFrom(Type /*!*/ fromType, DynamicMetaObject fromArg, ParameterWrapper /*!*/ toParameter, NarrowingLevel level)
{
var result = Converter.CanConvertFrom(fromArg, fromType, toParameter.Type, toParameter.ProhibitNull, level,
HasExplicitProtocolConversion(toParameter), _implicitProtocolConversions
);
if (result.Assumption != null)
{
if (_argumentAssumptions == null)
{
_argumentAssumptions = new List <Key <int, NarrowingLevel, Ast> >();
}
if (_argumentAssumptions.FindIndex((k) => k.First == toParameter.ParameterInfo.Position && k.Second == level) < 0)
{
_argumentAssumptions.Add(Key.Create(toParameter.ParameterInfo.Position, level, result.Assumption));
}
}
return(result.IsConvertible);
}
/// <summary>
/// Performs binding against a set of overloaded methods using the specified arguments. The arguments are
/// consumed as specified by the CallSignature object.
/// </summary>
/// <param name="minLevel">TODO.</param>
/// <param name="maxLevel">TODO.</param>
/// <param name="resolver">Overload resolver.</param>
/// <param name="targets">The methods to be called</param>
/// <param name="restrictions">Additional restrictions which should be applied to the resulting MetaObject.</param>
/// <param name="target">The resulting binding target which can be used for producing error information.</param>
/// <param name="name">The name of the method or null to use the name from targets.</param>
/// <returns>A meta object which results from the call.</returns>
public DynamicMetaObject CallMethod(DefaultOverloadResolver resolver, IList<MethodBase> targets, BindingRestrictions restrictions, string name,
NarrowingLevel minLevel, NarrowingLevel maxLevel, out BindingTarget target) {
ContractUtils.RequiresNotNull(resolver, "resolver");
ContractUtils.RequiresNotNullItems(targets, "targets");
ContractUtils.RequiresNotNull(restrictions, "restrictions");
// attempt to bind to an individual method
target = resolver.ResolveOverload(name ?? GetTargetName(targets), targets, minLevel, maxLevel);
if (target.Success) {
// if we succeed make the target for the rule
return new DynamicMetaObject(
target.MakeExpression(),
restrictions.Merge(
MakeSplatTests(resolver.CallType, resolver.Signature, resolver.Arguments).
Merge(target.RestrictedArguments.GetAllRestrictions())
)
);
}
// make an error rule
return MakeInvalidParametersRule(resolver, restrictions, target);
}
public bool HasConversionFrom(Type ty, NarrowingLevel allowNarrowing) {
if (ty == Type) return true;
if (ty == None.Type) {
if (_prohibitNull) return false;
if (Type.IsGenericType && Type.GetGenericTypeDefinition() == typeof(Nullable<>)) {
return true;
}
return !Type.IsValueType;
} else {
return _binder.CanConvertFrom(ty, Type, allowNarrowing);
}
}
public override bool CanConvertFrom(Type fromType, Type toType, bool toNotNullable, NarrowingLevel level)
{
//
// NarrowLevel.Zero
//
if (fromType == toType)
return true;
// I don't want to consider boxing before numeric conversion, else I don't get the convert-int-to-long behavior required to select Numbers.lt(long,long) over Numbers.lt(long,Object)
// We also need to get the narrow-long-to-int behavior required to avoid casting in host expression calls.
// IronRuby does this here:
//if (toType.IsAssignableFrom(fromType))
//{
// return true;
//}
if ( !Util.IsPrimitiveNumeric(fromType) && toType.IsAssignableFrom(fromType))
{
return true;
}
//
// NarrowingLevel.One
//
if (level < NarrowingLevel.One)
{
return false;
}
if (WideningIntegerConversion(fromType, toType))
{
return true;
}
//
// NarrowingLevel.Two
//
if (level < NarrowingLevel.Two)
{
return false;
}
if ( SpecialClojureConversion(fromType, toType) )
{
return true;
}
//if (fromType == typeof(char) && toType == typeof(string))
//{
// return true;
//}
if (toType == typeof(bool))
{
return true;
}
//
// NarrowingLevel.Three
//
if (level < NarrowingLevel.Three)
{
return false;
}
if ( Util.IsPrimitiveNumeric(toType) && Util.IsPrimitiveNumeric(fromType) )
{
return true;
}
//
// NarrowingLevel.All
//
if (level < NarrowingLevel.All)
{
return false;
}
// pick up boxing numerics here
if (toType.IsAssignableFrom(fromType))
{
return true;
}
return false;
//if (level == NarrowingLevel.All)
//{
// if (fromType == typeof(long))
// {
// if (toType == typeof(int) || toType == typeof(uint) || toType == typeof(short) || toType == typeof(ushort) || toType == typeof(byte) || toType == typeof(sbyte))
// return true;
// }
// else if (fromType == typeof(double))
// {
// if (toType == typeof(float))
// return true;
// }
//}
//return base.CanConvertFrom(fromType, toType, toNotNullable, level);
}
public override bool CanConvertFrom(Type fromType, Type toType, bool toNotNullable, NarrowingLevel level) {
return Converter.CanConvertFrom(fromType, toType, level);
}
/// <summary>
/// Returns true if fromArg of type fromType can be assigned to toParameter with a conversion on given narrowing level.
/// </summary>
public override bool CanConvertFrom(Type/*!*/ fromType, DynamicMetaObject fromArg, ParameterWrapper/*!*/ toParameter, NarrowingLevel level) {
return Converter.CanConvertFrom(fromArg, fromType, toParameter.Type, toParameter.ProhibitNull, level,
HasExplicitProtocolConversion(toParameter), _implicitProtocolConversions
);
}
public virtual bool CanConvertFrom(Type fromType, DynamicMetaObject fromArgument, ParameterWrapper toParameter, NarrowingLevel level) {
Assert.NotNull(fromType, toParameter);
Type toType = toParameter.Type;
if (fromType == typeof(DynamicNull)) {
if (toParameter.ProhibitNull) {
return false;
}
if (toType.IsGenericType && toType.GetGenericTypeDefinition() == typeof(Nullable<>)) {
return true;
}
if (!toType.IsValueType) {
return true;
}
}
if (fromType == toType) {
return true;
}
return _binder.CanConvertFrom(fromType, toType, toParameter.ProhibitNull, level);
}
public override Candidate SelectBestConversionFor(DynamicMetaObject/*!*/ arg, ParameterWrapper/*!*/ candidateOne,
ParameterWrapper/*!*/ candidateTwo, NarrowingLevel level) {
Type typeOne = candidateOne.Type;
Type typeTwo = candidateTwo.Type;
Type actualType = arg.GetLimitType();
if (actualType == typeof(DynamicNull)) {
// if nil is passed as a block argument prefers BlockParam over a missing block:
if (typeOne == typeof(BlockParam) && typeTwo == typeof(MissingBlockParam)) {
Debug.Assert(!candidateOne.ProhibitNull);
return Candidate.One;
}
if (typeOne == typeof(MissingBlockParam) && typeTwo == typeof(BlockParam)) {
Debug.Assert(!candidateTwo.ProhibitNull);
return Candidate.Two;
}
} else {
if (typeOne == actualType) {
if (typeTwo == actualType) {
// prefer non-nullable reference type over nullable:
if (!actualType.IsValueType) {
if (candidateOne.ProhibitNull) {
return Candidate.One;
} else if (candidateTwo.ProhibitNull) {
return Candidate.Two;
}
}
} else {
return Candidate.One;
}
} else if (typeTwo == actualType) {
return Candidate.Two;
}
}
// prefer integer type over enum:
if (typeOne.IsEnum && Enum.GetUnderlyingType(typeOne) == typeTwo) {
return Candidate.Two;
}
if (typeTwo.IsEnum && Enum.GetUnderlyingType(typeTwo) == typeOne) {
return Candidate.One;
}
return base.SelectBestConversionFor(arg, candidateOne, candidateTwo, level);
}
public override bool CanConvertFrom(Type fromType, DynamicMetaObject fromArg, ParameterWrapper toParameter, NarrowingLevel level)
{
if ((fromType == typeof(List) || fromType.IsSubclassOf(typeof(List))))
{
if (toParameter.Type.IsGenericType() &&
toParameter.Type.GetGenericTypeDefinition() == typeof(IList <>) &&
(toParameter.ParameterInfo.IsDefined(typeof(BytesConversionAttribute), false) ||
toParameter.ParameterInfo.IsDefined(typeof(BytesConversionNoStringAttribute), false)))
{
return(false);
}
}
else if (fromType == typeof(string))
{
if (toParameter.Type == typeof(IList <byte>) &&
!Binder.Context.PythonOptions.Python30 &&
toParameter.ParameterInfo.IsDefined(typeof(BytesConversionAttribute), false))
{
// string -> byte array, we allow this in Python 2.6
return(true);
}
}
else if (fromType == typeof(Bytes))
{
if (toParameter.Type == typeof(string) &&
!Binder.Context.PythonOptions.Python30 &&
toParameter.ParameterInfo.IsDefined(typeof(BytesConversionAttribute), false))
{
return(true);
}
}
return(base.CanConvertFrom(fromType, fromArg, toParameter, level));
}
/// <summary>
/// Selects the best (of two) candidates for conversion from actualType
/// </summary>
public virtual Candidate SelectBestConversionFor(DynamicMetaObject arg, ParameterWrapper candidateOne, ParameterWrapper candidateTwo, NarrowingLevel level) {
return Candidate.Equivalent;
}
public bool HasConversionFrom(Type fromType, NarrowingLevel level) {
return _binder.CanConvertFrom(fromType, this, level);
}
public override bool CanConvertFrom(Type fromType, Type toType, bool toNotNullable, NarrowingLevel level) {
// TODO: None -> nullable reference types?
return toType.IsAssignableFrom(fromType);
}
/// <summary> /// Determines if a conversion exists from fromType to toType at the specified narrowing level. /// toNotNullable is true if the target variable doesn't allow null values. /// </summary> public abstract bool CanConvertFrom(Type fromType, Type toType, bool toNotNullable, NarrowingLevel level);
internal static Convertibility CanConvertFrom(DynamicMetaObject fromArg, Type/*!*/ fromType, Type/*!*/ toType, bool toNotNullable,
NarrowingLevel level, bool explicitProtocolConversions, bool implicitProtocolConversions)
{
ContractUtils.RequiresNotNull(fromType, "fromType");
ContractUtils.RequiresNotNull(toType, "toType");
var metaConvertible = fromArg as IConvertibleMetaObject;
var rubyMetaConvertible = fromArg as IConvertibleRubyMetaObject;
//
// narrowing level 0:
//
if (toType == fromType) {
return Convertibility.AlwaysConvertible;
}
if (fromType == typeof(DynamicNull)) {
if (toNotNullable) {
return Convertibility.NotConvertible;
}
if (toType.IsGenericType() && toType.GetGenericTypeDefinition() == typeof(Nullable<>)) {
return Convertibility.AlwaysConvertible;
}
if (!toType.IsValueType()) {
// null convertible to any reference type:
return Convertibility.AlwaysConvertible;
} else if (toType == typeof(bool)) {
return Convertibility.AlwaysConvertible;
} else if (!ProtocolConversionAction.HasDefaultConversion(toType)) {
// null not convertible to a value type unless a protocol conversion is allowed:
return Convertibility.NotConvertible;
}
}
// blocks:
if (fromType == typeof(MissingBlockParam)) {
return new Convertibility(toType == typeof(BlockParam) && !toNotNullable, null);
}
if (fromType == typeof(BlockParam) && toType == typeof(MissingBlockParam)) {
return Convertibility.AlwaysConvertible;
}
if (toType.IsAssignableFrom(fromType)) {
return Convertibility.AlwaysConvertible;
}
if (HasImplicitNumericConversion(fromType, toType)) {
return Convertibility.AlwaysConvertible;
}
if (CompilerHelpers.GetImplicitConverter(fromType, toType) != null) {
return Convertibility.AlwaysConvertible;
}
if (rubyMetaConvertible != null) {
return rubyMetaConvertible.IsConvertibleTo(toType, false);
} else if (metaConvertible != null) {
return new Convertibility(metaConvertible.CanConvertTo(toType, false), null);
}
//
// narrowing level 1:
//
if (level < NarrowingLevel.One) {
return Convertibility.NotConvertible;
}
if (explicitProtocolConversions && ProtocolConversionAction.HasDefaultConversion(toType)) {
return Convertibility.AlwaysConvertible;
}
//
// narrowing level 2:
//
if (level < NarrowingLevel.Two) {
return Convertibility.NotConvertible;
}
if (HasExplicitNumericConversion(fromType, toType)) {
return Convertibility.AlwaysConvertible;
}
if (CompilerHelpers.GetExplicitConverter(fromType, toType) != null) {
return Convertibility.AlwaysConvertible;
}
if (CompilerHelpers.HasTypeConverter(fromType, toType)) {
return Convertibility.AlwaysConvertible;
}
if (fromType == typeof(char) && toType == typeof(string)) {
return Convertibility.AlwaysConvertible;
}
if (toType == typeof(bool)) {
return Convertibility.AlwaysConvertible;
}
if (rubyMetaConvertible != null) {
return rubyMetaConvertible.IsConvertibleTo(toType, true);
} else if (metaConvertible != null) {
return new Convertibility(metaConvertible.CanConvertTo(toType, true), null);
}
//
// narrowing level 3:
//
if (level < NarrowingLevel.Three) {
return Convertibility.NotConvertible;
}
if (implicitProtocolConversions && ProtocolConversionAction.HasDefaultConversion(toType)) {
return Convertibility.AlwaysConvertible;
}
// A COM object can potentially be converted to the given interface, but might also be not so use this only as the last resort:
if (TypeUtils.IsComObjectType(fromType) && toType.IsInterface()) {
return Convertibility.AlwaysConvertible;
}
return Convertibility.NotConvertible;
}
