public static SpecificationResult ParseSpecification(SymbolTable symbolTable, SpecificationContext context, Expression body)
{
if (body is MethodCallExpression methodCall)
{
var method = methodCall.Method;
if (method.DeclaringType == typeof(FactRepository) &&
method.Name == nameof(FactRepository.OfType))
{
var type = method.GetGenericArguments()[0];
var factType = type.FactTypeName();
var set = FactsOfType(factType, type);
var sourceSymbolValue = new SymbolValueSetDefinition(set);
var source = SpecificationResult.FromValue(sourceSymbolValue)
.WithTarget(set);
if (methodCall.Arguments.Count == 0)
{
return(source);
}
else
{
return(ParseWhere(source, symbolTable, context, methodCall.Arguments[0]));
}
}
else if (method.DeclaringType == typeof(Queryable))
{
if (method.Name == nameof(Queryable.Where) && methodCall.Arguments.Count == 2)
{
var source = ParseSpecification(symbolTable, context, methodCall.Arguments[0]);
return(ParseWhere(source, symbolTable, context, methodCall.Arguments[1]));
}
else if (method.Name == nameof(Queryable.Select) && methodCall.Arguments.Count == 2)
{
var source = ParseSpecification(symbolTable, context, methodCall.Arguments[0]);
return(ParseSelect(source, symbolTable, context, methodCall.Arguments[1]));
}
else if (method.Name == nameof(Queryable.SelectMany) && methodCall.Arguments.Count == 3)
{
var source = ParseSpecification(symbolTable, context, methodCall.Arguments[0]);
return(ParseSelectMany(source, symbolTable, context, methodCall.Arguments[1], methodCall.Arguments[2]));
}
else
{
throw new SpecificationException($"You cannot use {method.Name} in a Jinaga specification.");
}
}
else
{
throw new SpecificationException($"You cannot use {method.DeclaringType.Name}.{method.Name} in a Jinaga specification.");
}
}
else
{
throw new SpecificationException($"You cannot use the syntax {body} in a Jinaga specification.");
}
}
private static SpecificationResult ParseWhere(SpecificationResult source, SymbolTable symbolTable, SpecificationContext context, Expression predicate)
{
if (predicate is UnaryExpression {
Operand : LambdaExpression lambda
})
public static (SymbolValue symbolValue, string tag) ParseValue(SymbolTable symbolTable, SpecificationContext context, Expression expression)
{
if (expression is NewExpression newBody)
{
var names = newBody.Members != null
? newBody.Members.Select(member => member.Name)
: newBody.Constructor.GetParameters().Select(parameter => parameter.Name);
var values = newBody.Arguments
.Select(arg => ParseValue(symbolTable, context, arg).symbolValue);
var fields = names.Zip(values, (name, value) => KeyValuePair.Create(name, value))
.ToImmutableDictionary();
return(new SymbolValueComposite(fields), "");
}
else if (expression is MemberInitExpression memberInit)
{
var fields = memberInit.Bindings
.Select(binding => ParseMemberBinding(symbolTable, context, binding))
.ToImmutableDictionary();
return(new SymbolValueComposite(fields), "");
}
else if (expression is MemberExpression {
Member : PropertyInfo propertyInfo
} memberExpression)
{
switch (ParseValue(symbolTable, context, memberExpression.Expression))
{
case (SymbolValueComposite compositeValue, _) :
return(compositeValue.GetField(propertyInfo.Name), propertyInfo.Name);
case (SymbolValueSetDefinition setValue, string tag):
var role = propertyInfo.Name;
var predecessorType = propertyInfo.PropertyType.FactTypeName();
var setDefinition = setValue.SetDefinition.AppendChain(role, predecessorType, propertyInfo.PropertyType);
return(new SymbolValueSetDefinition(setDefinition), tag);
default:
throw new NotImplementedException();
}
}
