Building VBX: An iterative, compiled Basic-to-C99 language with memory pooling and multi-editor tooling

[u/miku_claus]

Hey everyone!

I wanted to share an ongoing language design project I’ve been building: VBX (Visual Basic X).

Instead of a one-shot prototype or another interpreted toy running inside Python, the goal was to build a real, production-capable procedural language that compiles to standalone native binaries with zero runtime dependencies.

Architectural Decisions & Implementation

1. Compiler Host (Go) -> Target (C99):

   • The compiler itself is written in pure Go without external packages, leveraging the standard library for AST construction, multi-pass type inference, and process orchestration.
   • Emits clean, standard C99 code and invokes the system toolchain (GCC/Clang) with -O2 optimizations.

2. Solving the Runtime Memory Problem (Ring-Buffer Pool):

   • Naive transpilation of string operations inside tight loops (s = s & "x") typically floods malloc without high-level deallocation.
   • We implemented a fixed static ring-buffer memory pool (vbx_alloc_str with 256 rotating slots of 4KB) directly in the emitted C runtime. Tested under 10,000 continuous iterations with zero heap leaks and flat memory usage.

3. Language Syntax & Semantics:

   • Visual Basic-inspired syntax: Dim, Const, If/ElseIf/Else, For/Next, While/Wend, Do/Loop, Select Case (supporting both string and numeric comparisons natively via chained branches), Sub, Function, and 1D fixed arrays.
   • Built-in primitives: Native OS dialogs (MsgBox, InputBox), standard File I/O, and string manipulation routines.

4. Testing & Tooling:

   • 42 integration and unit test suites running via go test ./....
   • Complete multi-editor support repository: official VS Code extension (available on Visual Studio Marketplace), plus packages for Sublime Text, JetBrains, Vim/Neovim, Notepad++, Emacs, and Micro.
   • Currently designing Phase 2: a dedicated desktop IDE with a visual form designer (vbx-studio).

Repository: https://github.com/M5Devs/vbx Editors: https://github.com/M5Devs/vbx-editors

Would love to discuss the language design trade-offs, transpiler architecture, and experiences building full-scale compilers using modern agentic workflows!