LogicaSharp

A .NET 10 implementation of the Logica programming language compiler, targeting T-SQL and ClickHouse.

Overview

LogicaSharp compiles Logica programs (a logic programming language for data manipulation) to SQL queries. It supports:

• Facts and Rules - Define data and transformations declaratively
• Joins - Automatic join generation from variable bindings
• Recursive CTEs - Transitive closure and graph traversal
• Aggregations - COUNT, SUM, MIN, MAX, AVG with GROUP BY
• Negation - NOT EXISTS subqueries
• Multiple Dialects - T-SQL (SQL Server) and ClickHouse

Examples

See Examples.md for detailed examples showing Logica programs and their generated T-SQL.

Quick Start

Compile a Logica file to T-SQL

dotnet run --project src/LogicaCompiler -- examples/ancestor_example.l -d mssql

Compile to ClickHouse

dotnet run --project src/LogicaCompiler -- examples/ancestor_example.l -d clickhouse

Use as a library

using LogicaSharp;

var source = @"
@Engine(""mssql"");
Parent(""Alice"", ""Bob"");
Parent(""Bob"", ""Carol"");

Ancestor(a, d) :- Parent(a, d);
Ancestor(a, d) :- Parent(a, c), Ancestor(c, d);
";

var sql = Logica.Compile(source, "Ancestor", "mssql");
Console.WriteLine(sql);

Project Structure

logicasharp/
├── src/
│   ├── LogicaSharp/           # Core library
│   │   ├── Parsing/           # Lexer and Parser
│   │   ├── Ast/               # Abstract Syntax Tree
│   │   ├── Compilation/       # SQL code generation
│   │   └── Dialects/          # T-SQL, ClickHouse
│   └── LogicaCompiler/        # Command-line tool
├── tests/
│   └── LogicaSharp.Tests/     # Unit and integration tests
├── examples/                   # Example Logica programs
└── Examples.md                 # Detailed examples with generated SQL

Building

dotnet build

Testing

dotnet test

The test suite includes 111 tests covering parsing, compilation, and LocalDB integration tests that execute generated SQL against SQL Server LocalDB.

License

Based on Logica by Google.