public static Expression MakeExpression(bool nullable, string members, Expression[] args)
{
// Warning: modifies args
if (args.Length == 0)
{
throw new LispException("Member accessor invoked without a target: {0}", members);
}
var names = members.Split(new char[] { '.' }, StringSplitOptions.RemoveEmptyEntries);
var code = args[0];
if (nullable)
{
var temp = Expression.Parameter(typeof(object));
for (var i = 0; i < names.Length; ++i)
{
Expression code2;
if (i < names.Length - 1)
{
var binder = Runtime.GetInvokeMemberBinder(new InvokeMemberBinderKey(names[i], 0));
code2 = Runtime.CompileDynamicExpression(binder, typeof(object), new Expression[] { code });
}
else
{
var binder = Runtime.GetInvokeMemberBinder(new InvokeMemberBinderKey(names[i], args.Length - 1));
args[0] = code;
code2 = Runtime.CompileDynamicExpression(binder, typeof(object), args);
}
code = Expression.Condition(Runtime.WrapBooleanTest(Expression.Assign(temp, code)), code2, Expression.Constant(null));
}
code = Expression.Block(typeof(object), new ParameterExpression[] { temp }, code);
}
else
{
for (var i = 0; i < names.Length; ++i)
{
if (i < names.Length - 1)
{
var binder = Runtime.GetInvokeMemberBinder(new InvokeMemberBinderKey(names[i], 0));
code = Runtime.CompileDynamicExpression(binder, typeof(object), new Expression[] { code });
}
else
{
var binder = Runtime.GetInvokeMemberBinder(new InvokeMemberBinderKey(names[i], args.Length - 1));
args[0] = code;
code = Runtime.CompileDynamicExpression(binder, typeof(object), args);
}
}
}
return(code);
}
