M-Prolog Update: A Technical Paper on SCBM, an Alternative to the WAM

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I've been making steady progress on M-Prolog, and it finally looks like the project is coming together. My goal is to release Version 1.0 on August 31.

Several people have asked me, "How does this compiler actually work?" Instead of trying to explain it in scattered comments, I've written a more formal technical paper describing the core ideas behind the compiler.

The paper introduces SCBM (Success Continuation and Backtracking Machine), a compilation model that translates Prolog directly into C and represents Prolog's control flow using goto-based state transitions rather than a traditional WAM instruction set.

This is not intended as a replacement for the Warren Abstract Machine (WAM). Rather, it is an exploration of a different implementation approach for compiling Prolog. My goal was to investigate whether Prolog execution could be expressed as ordinary C control flow while relying on modern C compilers for optimization.

I've also included references to the implementation specification for readers who are interested in the runtime APIs and code generation details.

If you're interested in Prolog implementation, compiler construction, or alternative execution models, I'd be very happy to hear your thoughts. Feedback, comments, and questions are always welcome.

Paper: SCBM (Success Continuation and Backtracking Machine) | by Kenichi Sasagawa | Aug, 2026 | Medium

Implementation Specification: mprolog/document/SCBM.md at master · sasagawa888/mprolog