// POWERLINERS — RUST POWERLINE

Why a port?

• Python interpreter startup adds ~100 ms per render — on every keystroke that triggers a zsh `precmd` redraw, every tmux statusline tick, every shell continuation line.
• At zpwr scale (256-thread workstation, 100+ zsh-in-tmux sessions), powerline-status compounds into seconds of cumulative latency per minute.
• Rust gives a static binary, microsecond startup, zero runtime deps, cross-arch builds, and predictable memory.
• The upstream theme grammar (JSON files in powerline/config/) is preserved verbatim — users keep their themes unchanged.

Targets

Port discipline

Every fn name landed in src/ported/ must exist in upstream powerline Python source. Enforced by tests/ported_fn_names_match_py.rs against docs/powerline_py_functions.txt (currently 631 names extracted from github.com/powerline/powerline). Maintainer-approved Rust-only exemptions live in tests/data/fake_fn_allowlist.txt.

# regenerate the upstream allowlist
./scripts/regen_py_functions.sh

# audit will fail with a list of any invented fn names
cargo test --test ported_fn_names_match_py

This pattern mirrors the zshrs ported_fn_names_match_c.rs enforcement — the audit test is load-bearing and must not be weakened.

Status

Port is structurally complete at the function level. 134 of 137 upstream Python files are at DONE tier per the citation-density classifier (scripts/gen_port_checklist.py); the 3 remaining NEAR files are class-only Python sources (readline.py, zsh.py, powerline-i3.py) at the classifier's architectural ceiling. The Rust port spans ~62,168 LOC across src/ported/ with 2,102 lib tests + 2 audit tests + 219 parity tests passing. Parity tests pipe identical inputs through the upstream Python interpreter (via the vendored powerline-status) and the Rust port, asserting byte/value-identical results — 11 real port bugs were surfaced by this harness and fixed in-tree (ThreadedSegment.daemon, Spec.did_type, encoding locale lookup, _clear_special_values UB, Spec.ident regex, Spec.context_message recursion, Spec.tuple bounds, Spec.unknown_msg/_spec dispatch, NON_PRINTABLE_RE inversion, Spec.printable/unsigned). Every fn name under src/ported/ traces to one of 631 upstream Python fn names (or to tests/data/fake_fn_allowlist.txt for maintainer-approved exemptions); every ported body carries // py:NNN line-citations against upstream powerline/. End-to-end statusline rendering against a real .json theme tree depends on the Powerline orchestrator chain (Powerline class + Renderer base + segment dispatcher) — wired up at the unit level, integration-glue is the remaining substrate. Watch tags for milestone bumps.

Install

# source + build
git clone https://github.com/MenkeTechnologies/powerliners.git
cd powerliners
cargo build
ls target/debug/powerliners target/debug/powerline-{render,lint,config,daemon}

Five binaries land in target/debug/: powerliners (demo CLI for ported leaf utilities), powerline-render, powerline-lint, powerline-config, and powerline-daemon. The daemon lifecycle (UNIX socket bind, daemonize, pidfile lock, accept loop, EOF shutdown) is fully functional; render returns a placeholder string until the Powerline orchestrator integration completes. powerline-render / powerline-lint / powerline-config shim through the ported scripts/ module mains — argparse and dispatch live, full pipelines depend on the same orchestrator chain.

Bundled segments

src/extensions/ ships net-new segments above upstream powerline-status, dispatched as standard built-ins via the daemon's ADAPTERS table. All accept a format theme arg and ship NF-default icons with Unicode + ASCII fallbacks (controlled by POWERLINERS_ICONS).

All segments live under src/extensions/<module>.rs and register through the daemon's ADAPTERS table in src/bin/shared/render_runtime.rs — see the audit section below for the live icon → segment cross-reference.

Glyph rendering

Every glyph below is a real Nerd Font codepoint loaded into this page via the @font-face block in docs/hud-static.css. The font is the official SymbolsNerdFont subset (~270 KB) served from jsdelivr CDN, with a unicode-range directive gating the load to PUA ranges only (U+E000-F8FF + U+F0000-FFFFD):

@font-face {
  font-family: 'SymbolsNerdFont';
  font-display: swap;
  src: url('https://cdn.jsdelivr.net/gh/ryanoasis/nerd-fonts@master/patched-fonts/NerdFontsSymbolsOnly/SymbolsNerdFont-Regular.ttf') format('truetype');
  unicode-range: U+E000-F8FF, U+F0000-FFFFD;
}

Body text and code blocks continue to render in Share Tech Mono / Orbitron — only PUA codepoints resolve through the NF subset, so the font swap has no layout impact. The same chain operates at runtime via POWERLINERS_ICONS: unset/default → NF glyph, =unicode → text-presentation Unicode fallback (e.g. ✓ ✗ 🐳 ⎈ ⛁), =ascii → label-style ASCII (e.g. OK FAIL D: k8s: D:).