Module thread_plan 

Pure thread create/start planning.

Owns decision logic shared by heddle start, heddle thread start, and heddle thread create:

• name validation (safe shell-token / reserved structure rules)
• default base selection rules
• path isolation requirements (pure checks on normalized paths/options)
• workspace mode planning from request + host facts

Materialization, checkout, registry writes, and repository I/O stay CLI-owned. Callers resolve states/paths first, then invoke these helpers.

Structs

ThreadCreateOptions

Caller-supplied create inputs for pure preflight planning.

ThreadCreatePlan

Pure plan for heddle thread create after name validation.

ThreadStartOptions

Caller-supplied start inputs for pure preflight planning.

ThreadStartPlan

Pure plan for heddle start / heddle thread start after option preflight.

Enums

AutoWorkspaceDefault

Config default used when --workspace auto and no explicit path forces a bytes-on-disk mode.

ExplicitPathPlacement

Where an explicit --path sits relative to the repository.

ThreadBaseError

Failures from pure base selection once states are resolved.

ThreadBaseSelection

Outcome of pure base selection after --from / existing tip are resolved.

ThreadPathIsolationError

Failures from pure path isolation checks.

ThreadPlanError

Failures from pure thread create/start planning.

WorkspaceModeRequest

Workspace mode as requested by the caller (maps from CLI --workspace).

Functions

active_reservation_blocks_start

Whether an active writer reservation blocks starting the same thread name.

active_reservation_path_matches

Whether a requested path matches the path held by an active reservation.

check_explicit_path_isolation

Pure path-isolation check for an explicit start path.

classify_explicit_path_placement

Classify an explicit start path relative to repo root / heddle dir.

explicit_path_allowed_for_git_overlay

Whether an explicit path placement is allowed for a git-overlay repo.

mode_honors_explicit_path

Whether the planned mode honors an explicit --path for checkout placement.

path_isolation_enforced

Whether path isolation is enforced for this capability.

plan_thread_create

Pure preflight for heddle thread create.

plan_thread_mode

Plan the concrete ThreadMode from the caller request and host facts.

plan_thread_start

Pure option preflight for heddle start / heddle thread start.

select_thread_base

Select the base state for a new or resumed thread start.

start_requires_clean_worktree

Whether heddle start must refuse a dirty worktree for these options.

validate_thread_name

Validate a thread name against the shared safe-slug rule.