// reads a construction component of a complex value
private IStonConstruction ReadConstruction(StonTokenReader reader)
{
reader.ExpectAndSkip(StonChartype.ConstructionOpen);
var positionalParameters = new List <IStonEntity>();
var namedParameters = new List <KeyValuePair <string, IStonEntity> >();
while (!reader.TryAndSkip(StonChartype.ConstructionClose))
{
// trying to read a positional parameter, or the first named parameter
if (namedParameters.Count == 0)
{
// value prompt right at the beginning clearly indicates a positional parameter
if (reader.TryAndSkip(StonChartype.ValuePrompt))
{
positionalParameters.Add(ReadEntity(reader));
}
// string literal might be an entity or a named parameter name
else if (reader.Peek().HasChartype(StonChartype.TextDelimiter))
{
var builder = new StringBuilder();
reader.ReadString(builder, false);
// if it's a single string literal followed by a value prompt, it means it is the first named parameter
if (reader.TryAndSkip(StonChartype.ValuePrompt))
{
namedParameters.Add(new KeyValuePair <string, IStonEntity>(builder.ToString(), ReadEntity(reader)));
}
// if no value prompt follows, it is assumed to be a string-valued entity
else
{
while (reader.Peek().HasChartype(StonChartype.StringChainContinue))
{
if (reader.ReadAndSkip().HasChartype(StonChartype.StringChainOpen))
{
builder.Append('\n');
}
reader.ReadString(builder, false);
}
positionalParameters.Add(ElementFactory.CreateSimpleEntity(ElementFactory.CreateSimpleValue(StonDataType.Text, builder.ToString())));
}
}
else
{
var entity = ReadEntity(reader);
if (reader.Peek().HasChartype(StonChartype.ValuePrompt))
{
// if value prompt follows after the read entity, it means the read entity must be a typeless, non-identified CANUN named value
// serving as the parameter name
if (!(entity is IStonSimpleEntity))
{
throw reader.MakeUnexpectedCharacterException(StonChartype.SequenceSeparator | StonChartype.ConstructionClose);
}
var simpleEntity = entity as IStonSimpleEntity;
if (simpleEntity.GlobalIdentifier != null || simpleEntity.Type != null || simpleEntity.Value.DataType != StonDataType.Named || simpleEntity.Value.Content.Contains('.'))
{
throw reader.MakeUnexpectedCharacterException(StonChartype.SequenceSeparator | StonChartype.ConstructionClose);
}
reader.ReadAndSkip();
namedParameters.Add(new KeyValuePair <string, IStonEntity>(simpleEntity.Value.Content, ReadEntity(reader)));
}
else
{
positionalParameters.Add(entity);
}
}
}
// reading remaining named parameters
else
{
string name;
if (reader.Peek().HasChartype(StonChartype.TextDelimiter))
{
name = reader.ReadString();
}
else if (reader.Peek().HasChartype(StonChartype.CanunBegin))
{
name = reader.ReadCanun();
}
else
{
throw reader.MakeUnexpectedCharacterException(StonChartype.TextDelimiter | StonChartype.CanunBegin);
}
reader.ExpectAndSkip(StonChartype.ValuePrompt);
IStonEntity value = ReadEntity(reader);
namedParameters.Add(new KeyValuePair <string, IStonEntity>(name, value));
}
if (reader.TryAndSkip(StonChartype.SequenceSeparator))
{
continue;
}
else if (!reader.Peek().HasChartype(StonChartype.ConstructionClose))
{
throw reader.MakeUnexpectedCharacterException(StonChartype.SequenceSeparator | StonChartype.ConstructionClose);
}
}
return(ElementFactory.CreateConstruction(positionalParameters, namedParameters));
}