DAC: DAC — Literate Programming Tool Revival

DAC is a small, dependency-light literate programming tool that extracts (“tangles”) named code chunks and renders (“weaves”) source documents.

Revival status

This repository is in investigation and stabilization. The canonical Tcl tangler and historical Perl draft pass their original nested-expansion tests. The Tcl core also has focused coverage for final source lines without trailing newlines and standalone weave terminators. The repaired dac-hfd.tcl is retained under D-008 as an experimental workflow incubator. Its test/green paths are characterized previews; no HFD command is currently a stable supported interface.

Current implementations

dac.tcl: canonical Tcl source and public executable (D-010; the extensionless dac mirror has been removed, reversing D-005's original authority designation at the user's request for scripts to carry a file extension).
historical/dac.pl: unsupported early Perl draft, retained for historical reference.
dac-hfd.tcl: D-008 experimental workflow incubator for builds, advisory lint, embedded tests, TDD presentation, and watch polling. A thin CLI dispatcher since the D-008 workflow-layer split; its components (hfd-common.tcl, hfd-build.tcl, hfd-lint.tcl, hfd-testrunner.tcl, hfd-watch.tcl) are small, explicit-input/output sibling files — see ARCHITECTURE.md.
*.dac: literate source and examples.
Committed derivatives: day01.py, day01.md, test_input.txt, hello_world.pl, and hello_world.md; their .dac sources are authoritative.

Verified commands

prove -v
tclsh dac.test
tclsh dac-hfd.test
tclsh dac-hfd-components.test
./dac.tcl -t -R day01.py day01.dac

Known risks

Recursive chunk cycles now have application-level detection under D-007. Malformed/unterminated inputs lack declared diagnostics. An automated derivative reproducibility gate remains to be implemented. See STATUS.md and COMPATIBILITY.md.

Governance

Agent behavior is canonical in AGENTS.md. Architecture is canonical in ARCHITECTURE.md. Semantic governance is canonical in SPEECHACT.md. Any meaningful behavior or architecture change must update relevant documentation in the same unit of work.