CompactHeterogeneousTree 2.1.0

The C# library

C# library for CHT.

The C# library is distributed on nuget.org.

The ChtSerializer class is used to Serialize/Deserialize values to/from CHT. CHT does not inherently define any types and their serializations. To convert between CHT nodes and CLR types the ChtSerializer needs a collection of mappers - implementations of IChtMapper. These mappers can be defined by the user, but some common mappers are predefined and can be registered using extension methods: AddStringMapper, AddObjectMapper, AddEnumMapper, AddIntMapper, etc., or all at once using AddCommonMappers. The predefined object mapper and enum mapper read attributes ChtFlattenAttribute, ChtIgnoreAttribute, ChtTypeAttribute. If the predefined enum mapper is to be used for deserialization, it either always needs a precise target or they need to be provided with a collection of supported types. If the predefined object mapper is to be used for deserialization, it needs to be provided with a collection of supported types. The object mapper flattens List<T> properties.

Types and serializer for the AST example can be defined as:

var serializer = new ChtSerializer()
    .AddObjectMapper<Node>()
    .AddIEnumerableMapper()
    .AddMapper(new SymbolMapper())
    .AddMapper(new IntLiteralMapper())
    .AddMapper(new StringLiteralMapper())

public class SymbolMapper : ChtMapper<Symbol>
{
    public override bool FromNode(ChtNode node, ChtSerializer serializer, out Symbol output)
    {
        if (node is ChtTerminal terminal && terminal.IsJustRaw && terminal.Raw.StartsWith("$"))
        {
            output = new Symbol { Name = terminal.Raw[1..] };
            return true;
        }
        output = default;
        return false;
    }

    public override bool ToNode(Symbol value, ChtSerializer serializer, out ChtNode output)
    {
        output = new ChtTerminal { Raw = "$" + value.Name };
        return true;
    }
}

public class IntLiteralMapper : ChtMapper<IntLiteral>
{
    public override bool FromNode(ChtNode node, ChtSerializer serializer, out IntLiteral output)
    {
        if (node is ChtTerminal terminal && terminal.IsJustRaw)
        {
            if (int.TryParse(terminal.Raw, out var value))
            {
                output = new IntLiteral { Value = value };
                return true;
            }
        }
        output = default;
        return false;
    }

    public override bool ToNode(IntLiteral value, ChtSerializer serializer, out ChtNode output)
    {
        output = new ChtTerminal { Raw = value.ToString() };
        return true;
    }
}

public class StringLiteralMapper : ChtMapper<StringLiteral>
{
    public override bool FromNode(ChtNode node, ChtSerializer serializer, out StringLiteral output)
    {
        if (node is ChtTerminal terminal && terminal.IsJustQuoted)
        {
            output = new StringLiteral { Value = terminal.Quoted };
            return true;
        }
        output = default;
        return false;
    }

    public override bool ToNode(StringLiteral value, ChtSerializer serializer, out ChtNode output)
    {
        output = new ChtTerminal { Quoted = value.ToString() };
        return true;
    }
}

public abstract class Node
{
}

public class Block : Node
{
    public List<Node> Children { get; set; } = [];
}

[ChtType("List")]
public class ListLiteral : Node
{
    public List<Node> Children { get; set; } = [];
}

public class Symbol : Node
{
    public required string Name { get; set; }
}

public class Assignment : Node
{
    public required Symbol Variable { get; set; }
    public required Node Value { get; set; }
}

public class MethodCall : Node
{
    public required Node Object { get; set; }
    public required Symbol Method { get; set; }
    public List<Node> Arguments { get; set; } = [];
}

public class FunctionCall : Node
{
    public required Node Function { get; set; }
    public List<Node> Arguments { get; set; } = [];
}

public class Indexing : Node
{
    public required Node Data { get; set; }
    public required Node Index { get; set; }
}

public class StringLiteral : Node
{
    public required string Value { get; set; }
}

public class IntLiteral : Node
{
    public required int Value { get; set; }
}