private static LightExpression.Expression <Func <Source, Dest, ResolutionContext, Dest> > CreateLightExpression()
{
var srcParam = L.Parameter(typeof(Source), "source");
var destParam = L.Parameter(typeof(Dest), "dest");
var exceptionVar = L.Parameter(typeof(Exception), "ex");
var typeMapDestVar = L.Parameter(typeof(Dest), "d");
var resolvedValueVar = L.Parameter(typeof(int), "val");
var expression = L.Lambda <Func <Source, Dest, ResolutionContext, Dest> >(
L.Block(
L.Condition(
L.Equal(srcParam, L.Constant(null)),
L.Default(typeof(Dest)),
L.Block(typeof(Dest), new[] { typeMapDestVar },
L.Assign(
typeMapDestVar,
L.Coalesce(destParam, L.New(typeof(Dest).GetTypeInfo().DeclaredConstructors.First()))),
L.TryCatch(
/* Assign src.Value */
L.Block(new[] { resolvedValueVar },
L.Block(
L.Assign(resolvedValueVar,
L.Condition(L.Or(L.Equal(srcParam, L.Constant(null)), L.Constant(false)),
L.Default(typeof(int)),
L.Property(srcParam, "Value"))
),
L.Assign(L.Property(typeMapDestVar, "Value"), resolvedValueVar)
)
),
L.Catch(exceptionVar,
L.Throw(
L.New(typeof(AutoMapperException).GetTypeInfo().DeclaredConstructors.First(),
L.Constant("Error mapping types."),
exceptionVar),
typeof(int))) // should skip this, cause does no make sense after the throw
),
typeMapDestVar))
),
srcParam, destParam, L.Parameter(typeof(ResolutionContext), "_")
);
return(expression);
}