r_pool_launcher()

Return a Pool.create() launcher

Usage

r_pool_launcher(
    *,
    rscript=None,
    stdout=None,
    stderr=None,
)

spawning R workers.

Each worker runs the R package mizu: the returned callable(token, slot) spawns rscript on the package’s static child runner with mizu:::worker_main(<token>, <slot>) as the entry expression and the probed library paths propagated in argv (without them the workers cannot library(mizu) from the host’s libraries). The mirror of the R package’s mizu_py_pool_launcher().

Parameters

rscript: str | None = None: Path to Rscript; the default searches the PATH.
stdout: _Any = None: Forwarded to subprocess.Popen.
stderr: _Any = None: Forwarded to subprocess.Popen.

Returns

A callable(token, slot) launcher for: Pool.create().

Raises

MizuError: Raised here, before any pool exists, when Rscript is not found or no installed mizu with source string support is available.

Notes

The first worker’s join records the workers’ language in the pool, so the launcher carries no language attribute: a pool of R workers takes pymizu.call() specifications through Pool.submit(), and a plain callable errors locally naming the spec verb. A launcher that spawns the wrong language fails at join, not at the first task.

Examples

import pymizu

with pymizu.Pool.create(4, launcher=pymizu.r_pool_launcher()) as pool:
    spec = pymizu.call(source="summary(cars$speed)")
    print(pool.submit(spec).collect())