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FScript

Compile vs Run

Compile vs Run

One of the most important current implementation details is that fscript run and fscript compile do not yet have identical internals.

run

run is built on the shared frontend, shared IR, runtime, and interpreter path. It is the broadest current execution route and the main behavioral reference point while the compiler matures.

compile

compile already produces executables, but the pipeline is mixed:

  • a real Cranelift-backed native slice exists
  • broader coverage is still supported by packaging the program into an embedded-runner bridge

Why this matters

A program that works with run may not yet exercise the fully native backend, even if compile can still build an executable for it through the bridge.

That is not a contradiction. It is simply a staging strategy:

  • keep one shared execution truth for behavior
  • expand real native lowering gradually
  • avoid inventing multiple incompatible semantics

When testing an important program:

  1. fscript check
  2. fscript run
  3. fscript compile

This gives you the clearest signal about both language correctness and current compiler maturity.

Long-term goal

The roadmap is for the compile pipeline to grow until the broader bridge becomes unnecessary and the real native path owns the full supported language subset.