/// <summary>
/// Default implementation of <see cref="IAccessorVisitor.Visit"/> that supports evaluation of intrinsic
/// functions Number(), String(), Boolean().
/// By overriding this any binding to to external objects can be achieved (recall to call this base
/// method when overriding).
/// </summary>
/// <param name="frame">The current frame (gives access to the next frame if any).</param>
public virtual PExpr Visit(IAccessorFrame frame)
{
IAccessorMemberFrame head = frame as IAccessorMemberFrame;
// We can only handle member access at the root level:
if (head == null)
{
return(frame.SetError());
}
// Lookup from the longest path to the head in registered objects:
// more "precise" objects mask root ones.
var deepestMemberFrame = frame.NextAccessors(true)
.Select(f => f as IAccessorMemberFrame)
.TakeWhile(f => f != null)
.LastOrDefault();
// We obtain at least the head, hence the do...while.
do
{
RuntimeObj obj;
if (_objects.TryGetValue(deepestMemberFrame.Expr.MemberFullName, out obj))
{
return(deepestMemberFrame.SetResult(obj));
}
deepestMemberFrame = deepestMemberFrame.PrevMemberAccessor;
}while(deepestMemberFrame != null);
var s = frame.GetImplementationState(c =>
c.On("Number").OnCall((f, args) =>
{
if (args.Count == 0)
{
return(f.SetResult(DoubleObj.Zero));
}
return(f.SetResult(args[0] as DoubleObj ?? DoubleObj.Create(args[0].ToDouble())));
}
)
.On("String").OnCall((f, args) =>
{
if (args.Count == 0)
{
return(f.SetResult(StringObj.EmptyString));
}
return(f.SetResult(StringObj.Create(args[0].ToString())));
})
.On("Boolean").OnCall((f, args) =>
{
return(f.SetResult(args.Count == 1 && args[0].ToBoolean() ? BooleanObj.True : BooleanObj.False));
})
);
return(s != null?s.Visit() : frame.SetError());
}
public override PExpr Visit(IAccessorFrame frame)
{
var s = frame.GetImplementationState(c =>
c.On("ToString").OnCall((f, args) =>
{
int radix = 10;
if (args.Count == 1)
{
radix = JSSupport.ToInt32(args[0].ToDouble());
}
if (radix < 2 || radix > 36)
{
return(f.SetError("Radix must be between 2 and 36."));
}
return(f.SetResult(StringObj.Create(JSSupport.ToString(_value, radix))));
}
));
return(s != null?s.Visit() : frame.SetError());
}
public override PExpr Visit(IAccessorFrame frame)
{
var s = frame.GetImplementationState(c =>
c.OnIndex((f, arg) =>
{
int idx = JSSupport.ToInt32(arg.ToDouble());
if (idx < 0 || idx >= _value.Length)
{
return(f.SetResult(EmptyString));
}
return(f.SetResult(Create(new string( _value[idx], 1 ))));
})
.On("ToString").OnCall((f, args) =>
{
return(f.SetResult(this));
}
));
return(s != null?s.Visit() : frame.SetError());
}
public override PExpr Visit(IAccessorFrame frame)
{
var s = frame.GetImplementationState(c => c
.On("AnIntrinsicArray").OnIndex((f, idx) =>
{
if (idx.Type != "number")
{
return(f.SetError("Number expected."));
}
int i = JSSupport.ToInt32(idx.ToDouble());
if (i < 0 || i >= AnIntrinsicArray.Length)
{
return(f.SetError("Index out of range."));
}
return(f.SetResult(DoubleObj.Create(AnIntrinsicArray[i])));
})
.On("An").On("array").On("with").On("one").On("cell").OnIndex((f, idx) =>
{
return(f.SetResult(StringObj.Create("An.array.with.one.cell[] => " + idx.ToString())));
})
.On("array").OnIndex((f, idx) =>
{
throw new Exception("Accessing XXX.array other than 'An.Array' must not be found.");
})
.On("Ghost").On("M").OnCall((f, args) =>
{
Console.WriteLine("Ghost.M() called with {0} arguments: {1} (=> returns {0}).",
args.Count,
string.Join(", ", args.Select(a => a.ToString())));
return(f.SetResult(DoubleObj.Create(args.Count)));
})
.On("Ghost").On("M").OnIndex((f, idx) =>
{
Console.WriteLine("Ghost.M[{0}] called (=> returns {0}).", JSSupport.ToInt32(idx.ToDouble()));
return(f.SetResult(idx));
})
);
return(s == null?base.Visit(frame) : s.Visit());
}