forth_bootslop/attempt_1/attempt_1.md

Technical Outline: Attempt 1

Overview

attempt_1 is a minimal C program that serves as a proof-of-concept for the "Lottes/Onat" sourceless ColorForth paradigm. It successfully integrates a visual editor, a live JIT compiler, and an execution environment into a single, cohesive Win32 application that links against the C runtime but avoids direct includes of standard headers, using manually declared functions instead.

The application presents a visual grid of 32-bit tokens and allows the user to navigate and edit them directly. On every keypress, the token array is re-compiled into x86-64 machine code and executed, with the results (register states and global memory) displayed instantly in the HUD.

Core Concepts Implemented

1. Sourceless Token Array (FArena tape):

   • The "source code" is a contiguous block of U4 (32-bit) integers allocated by VirtualAlloc and managed by the FArena from duffle.h.
   • Each token is packed with a 4-bit "Color" tag and a 28-bit payload, adhering to the core design.

2. Annotation Layer (FArena anno):

   • A parallel FArena of U8 (64-bit) integers stores an 8-character string for each corresponding token on the tape.
   • The UI renderer prioritizes displaying this string, but the compiler only ever sees the indices packed into the 32-bit token.

3. 2-Register Stack & Global Memory:

   • The JIT compiler emits x86-64 that strictly adheres to Onat's RAX/RDX register stack.
   • A vm_globals array is passed by pointer into the JIT'd code (via RCX on Win64), allowing instructions like FETCH and STORE to simulate the "tape drive" memory model.

4. Handmade x86-64 JIT Emitter:

   • A small set of emit8/emit32 functions write raw x86-64 opcodes into a VirtualAlloc block marked as executable (PAGE_EXECUTE_READWRITE).
   • This buffer is cast to a C function pointer and called directly, bypassing the need for an external assembler like NASM or a complex library like Zydis for this prototype stage.

5. Modal Editor (Win32 GDI):

   • The UI is built with raw Win32 GDI calls defined in duffle.h.
   • It features two modes: Navigation (gray cursor, arrow key movement) and Edit (orange cursor, text input).
   • The editor correctly handles token insertion, deletion (Vim-style backspace), tag cycling (Tab), and value editing, all while re-compiling and re-executing on every keystroke.

6. O(1) Dictionary & Visual Linking:

   • The dictionary relies on an edit-time visual linker. When the tape is modified, relink_tape resolves names to absolute source memory indices.
   • The compiler resolves references in O(1) time instantly by indexing into an offset mapping table (tape_to_code_offset).

7. Implicit Definition Boundaries (Magenta Pipe):

   • Definitions implicitly cause the JIT to emit a RET to close the prior block, and an xchg rax, rdx to rotate the stack for the new block.

8. x68 Instruction Padding:

   • The JIT pads every logical block/instruction to exact 32-bit multiples using 0x90 (NOPs) to perfectly align with the visual token grid logic.

9. The FFI Bridge:

   • The system uses an FFI macro (emit_ffi_dance) to align the RSP stack to 16 bytes, allocate 32 bytes of shadow space, and map the 2-register data stack/globals into the Windows C-ABI (RCX, RDX, R8, R9) to safely call WinAPI functions (like MessageBoxA).

What's Missing (TODO)

• Saving/Loading (Persistence): The tape and annotation arenas are purely in-memory and are lost when the program closes. Need to implement the self-modifying OS cartridge concept.
• Expanded Instruction Set: The JIT only knows a handful of primitives. It has no support for floating point or more complex branches.
• Annotation Editing & Comments: Typing into an annotation just appends characters up to 8 bytes. A proper text-editing cursor within the token is needed, and support for arbitrarily long comments should be implemented.
• Tape Drive / Preemptive Scatter Logic: Improve the FFI argument mapping to properly read from the "tape drive" memory slots instead of just mapping RAX/RDX to the first parameters.

References Utilized

• Heavily Utilized:
  • Onat's Talks: The core architecture (2-register stack, global memory tape, JIT philosophy) is a direct implementation of the concepts from his VAMP/KYRA presentations.
  • Lottes' Twitter Notes: The 2-character mapped dictionary, ret-if-signed (RET_IF_ZERO), and annotation layer concepts were taken directly from his tweets.
  • User's duffle.h & fortish-study: The C coding conventions (X-Macros, FArena, byte-width types, ms_ prefixes) were adopted from these sources.
• Lightly Utilized:
  • Lottes' Blog: Provided the high-level "sourceless" philosophy and inspiration.
  • Grok Searches: Served to validate our understanding and provide parallels (like Wasm's linear memory), but did not provide direct implementation details.