selfhosting: move ny-parser-nyash into apps/selfhost/, add Ny-only dev loop and initial dep tree tools; add docs plan; make dev/dev-watch

tools/dev_selfhost_loop.sh

@@ -0,0 +1,109 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Nyash self-hosting dev loop helper
+# Goals:
+# - Avoid repeated Rust builds; iterate on .nyash scripts only
+# - One-time ensure binary exists; then run with VM (default) or MIR
+# - Optional watch mode that re-runs on file changes (uses entr/inotifywait if available)
+
+ROOT_DIR=$(cd "$(dirname "$0")/.." && pwd)
+BIN="$ROOT_DIR/target/release/nyash"
+
+SCRIPT="apps/selfhost-minimal/main.nyash"
+BACKEND="vm"
+WATCH=0
+LOAD_STD=0
+VERBOSE=0
+EXTRA_ARGS=()
+
+usage() {
+  cat <<EOF
+Usage: tools/dev_selfhost_loop.sh [options] [script.nyash] [-- ARGS]
+
+Options:
+  --watch           Re-run on file changes (apps/**/*.nyash)
+  --backend <mode>  interpreter|mir|vm (default: vm)
+  --std             Load Ny std scripts from nyash.toml ([ny_plugins])
+  -v, --verbose     Verbose CLI output
+  -h, --help        Show this help
+
+Examples:
+  # One-off run (VM), minimal selfhost sample
+  tools/dev_selfhost_loop.sh apps/selfhost-minimal/main.nyash
+
+  # Watch mode with Ny std libs loaded
+  tools/dev_selfhost_loop.sh --watch --std apps/selfhost/ny-parser-nyash/main.nyash
+
+EOF
+}
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --watch) WATCH=1; shift ;;
+    --backend) BACKEND="$2"; shift 2 ;;
+    --std) LOAD_STD=1; shift ;;
+    -v|--verbose) VERBOSE=1; shift ;;
+    -h|--help) usage; exit 0 ;;
+    --) shift; EXTRA_ARGS=("${@}"); break ;;
+    *.nyash) SCRIPT="$1"; shift ;;
+    *) EXTRA_ARGS+=("$1"); shift ;;
+  esac
+done
+
+if [[ ! -f "$BIN" ]]; then
+  echo "[dev] nyash binary not found; building release (one-time)..."
+  (cd "$ROOT_DIR" && cargo build --release --features cranelift-jit)
+fi
+
+run_once() {
+  local envs=("NYASH_DISABLE_PLUGINS=1")
+  if [[ "$LOAD_STD" -eq 1 ]]; then
+    envs+=("NYASH_LOAD_NY_PLUGINS=1")
+  fi
+  if [[ "$VERBOSE" -eq 1 ]]; then
+    envs+=("NYASH_CLI_VERBOSE=1")
+  fi
+  echo "[dev] running: ${envs[*]} $BIN --backend $BACKEND $SCRIPT ${EXTRA_ARGS[*]}"
+  (cd "$ROOT_DIR" && \
+    env ${envs[@]} "$BIN" --backend "$BACKEND" "$SCRIPT" "${EXTRA_ARGS[@]}" )
+}
+
+if [[ "$WATCH" -eq 0 ]]; then
+  run_once
+  exit $?
+fi
+
+# Watch mode
+echo "[dev] watch mode ON (backend=$BACKEND, std=$LOAD_STD)"
+FILES_CMD="rg --files --glob 'apps/**/*.nyash'"
+
+if command -v entr >/dev/null 2>&1; then
+  # Use entr for reliable cross-platform watching
+  echo "[dev] using 'entr' for file watching"
+  # Feed a stable, sorted file list to entr; rerun on any change
+  eval "$FILES_CMD" | sort | entr -rs "bash -lc '$(printf %q "$ROOT_DIR")/tools/dev_selfhost_loop.sh --backend $(printf %q "$BACKEND") $( ((LOAD_STD)) && echo --std ) $( ((VERBOSE)) && echo -v ) $(printf %q "$SCRIPT") ${EXTRA_ARGS:+-- ${EXTRA_ARGS[*]@Q}}'"
+  exit $?
+fi
+
+if command -v inotifywait >/dev/null 2>&1; then
+  echo "[dev] using 'inotifywait' for file watching"
+  while true; do
+    run_once || true
+    # Block until any .nyash under apps changes
+    inotifywait -qq -r -e close_write,create,delete,move "$ROOT_DIR/apps" || true
+  done
+  exit 0
+fi
+
+# Fallback: naive polling on mtime hash every 1s
+echo "[dev] no watcher found; falling back to 1s polling"
+prev_hash=""
+while true; do
+  cur_hash=$( (cd "$ROOT_DIR" && eval "$FILES_CMD" | xargs -r stat -c '%Y %n' 2>/dev/null | md5sum | awk '{print $1}') )
+  if [[ "$cur_hash" != "$prev_hash" ]]; then
+    prev_hash="$cur_hash"
+    run_once || true
+  fi
+  sleep 1
+done