kanchi (感知 — "sensing / perception")

Typed environment-discovery primitive for the pleme-io fleet — the shikumi discovered() tier made declarative.

Every GPU/terminal app faces the same domain: probe the host for the best-fit value, fall back to a documented default when it can't, expose the result as a discoverable tier. Hand-rolled, that's the same trio per axis, in every app:

pub const FALLBACK_X: T = ...;
pub fn detect_x() -> Option<T> { /* subtle, re-vendored platform FFI */ }
pub fn detect_x_or_fallback() -> T { detect_x().unwrap_or(FALLBACK_X) }

kanchi collapses the whole domain into a declaration — and the platform FFI (NSScreen, sysctl hw.memsize, /proc/meminfo, AppleInterfaceStyle) lives once, in kanchi::probe:

kanchi::defaxes! {
    /// Display-fit window size; falls back to 1200×800.
    window_dims: (u32, u32) = (1200, 800)
        => || kanchi::probe::screen_frac(0.60, (800, 600), (1600, 1100));
    /// DPR-aware font size — Retina 14pt / low-DPI 16pt.
    font_size: f32 = 14.0 => || kanchi::probe::dpr_font_size(14.0, 16.0);
    /// Scrollback scaled to physical RAM.
    scrollback_lines: u32 = 10_000
        => || kanchi::probe::total_ram_gib().map(|g| if g >= 16 { 100_000 } else { 10_000 });
    /// Not-yet-wired axis degenerates cleanly to the fallback.
    theme: &'static str = "nord" => kanchi::none;
}

Each line generates FALLBACK_<NAME> + detect_<name>() -> Option<T> + detect_<name>_or_fallback() -> T. A probe is any no-arg callable returning Option<T> (a fn path or a || … closure baking in args); use [kanchi::none] for axes whose detection isn't wired yet.

probes (kanchi::probe)

Why it exists

The prime-directive case: the identical trio appears ~7× in mado and is needed in tear / escriba / namimado / ayatsuri / seki — ~126 hand-authored items the fleet would otherwise re-vendor, each a place for drift, a format!() violation, or a divergent platform-FFI path. kanchi makes the discovered tier as cheap to author as prescribed_default() is, with fallbacks meant to be sourced from the same ishou::FleetDefaults the prescribed tier reads.

mado is the reference consumer (mado/src/auto_detect.rs).

License

MIT