README

MCH_Delphi_Software

GitHub repo for open sourced MCH Software.

Most recent (2026) development is in Common/MemDB2:

• Builds on MemDB code, quick, and developed up to the end of 2025.
• They share the same file format and API's.
• MemDB now legacy code. Will be removed start of Dec 2026.
• MemDB now has an upgrade tool (to MemDB2 format) on the MemDB_Upgrade_Tool branch.
• MemDB2 better for more deeply parallel / async workloads.
• MemDB2 now has C API, and pre-built binaries for Visual Studio jockeys.
• Now suitable for general use, with many bugfixes from AI reivew. Significantly more robust.
• Docs\ folder contains Claude code review for those of you worried about code quality.
• MemDB2 now compiles & runs on both Win32/64 and Android 32/64
• SQL support for MemDB2 in progress.

Also:

• TP Lex / Yacc port for Delphi now at: https://github.com/MartinCHarvey/MCH-TPLY41
  • Now has an OO mode "-oo" for generating object orientated code.
  • Support via additional declarations "%classname" "%classdecl" "%classfunc" "%classvar" for OO encapsultated lexers and parsers.

If any of you folks get some of this to compile / run under the FPC compiler, I'd be very interested to know.

martin_c_harvey@hotmail.com

Summary of contents.

Files / Folders:

• KnowComment: A Delphi client for Instagram (and eventually Twitter too, but needs a few fixes). Needs port to MemDB2 in the next month.
• CoCoDM: A Delphi port of the CoCo/R parser generator.
• ProjectXPlant: A handy utility which parses delphi project files and copies projects from one location to another.
• CheckIn: Simple hard-coded COVID-19 inspired web application.
  • Requires users to check-in online regularly.
  • Sends notifications to nominated contacts if they don't.
• Sudoku: A sudoku solver.
  • Simple testapp for Exact cover DLX algorithm. Allows you to load, save, and solve sudoku problems fast.
• Sudoku / Symmetries.
  • Some ways of finding isomorphic board configurations.
    • Graph method has errors, but included for interest.
    • Fastest is "CellCountMT", still being optimised.
• NQueens: Solves the N queens problem.
  • Another, perhaps simpler, example of the Exact cover algorithm.
• MFract.
  • A simple fractal generator (Mandelbrot / Julia). Install MCHComponents bpl first.

Common: Common utility code, including:

• MCHComponents visual component library (required for MFract - TSizeableImage).
  • Open project, right click MCHComponents.bpl, select "install" to add to IDE palette.
• Raw AVL tree.
• Copy on write AVL tree (CowTree).
• Read and Write cached memory streams.
• Doubly linked lists.
• HTML / JSON / CSS / Javascript parsers.
• HTTP fetcher.
• Combined HTTP fetch and document parse.
• Indexed store (see http://www.martincharvey.net/ for more info).
• Logging code.
• Lightweight in memory database engine. Currently suitable for relatively small (in modern terms) datasets. E-mail me for an explanation of limitations.
• Ordinal set handling.
• Reconfigurable lexer.
• Custom object streaming system.
• Debug object tracking.
• Custom threadpool implementation.
• Sparse Matrices.
• DLX like "Algorithm X" implementation for the exact cover problem.
• Parallelizer: Spawn threads to run method invocations in parallel.

Additional testapps and utility code.

• CoWTree testapp: Common/CowTree/Test
• MemDB testapp: Common/MemDB/Test/
• Lexer testapp: Common/SoftLexer/Test/
• Streaming system testapp: Common/StreamingSystem/Test/
• Threadpool testapp: Common/WorkItems/Test/
• Threadpool testapp: Common/WorkItems/Test2/
• Threadpool testapp: Common/WorkItems/Test3/
• Instagram / Twitter importer testapp MMapper/
• FetchParse library testapp: PageMapper/
• Sparse Matrix testapp Commmon/SparseMatrix/Test
• ExactCover testapp Common/ExactCover/Test
• Batch Sudoku solver (Sudoku/BatchThreadedSolver)

Future development plans:

• Clean up parser error recovery code with a "standard" lexer.
• MemDB: Query engine.
• Investigate compilability under FreePascal compiler.

Comments / queries to martin_c_harvey@hotmail.com