wch

# @drob's version from https://twitter.com/drob/status/1501747414780239879
pluck_recursive <- function(lst, name) {
  if (is.list(lst)) {
    if (!is.null(lst[[name]])) {
      return(lst[[name]])
    }
    return(unname(unlist(purrr::map(lst, pluck_recursive, name))))
  }
}

wch

library(inline)
get_mtime <- cfunction(
  signature(filename = "character"),
  includes = "
    #include <time.h>
    #include <sys/stat.h>",
  body = '
    const char* path = CHAR(asChar(filename));
    struct stat attr;
    stat(path, &attr);

wch

# Demonstration of using ContextVars instead of global variables.

# Set to True for global mode, False for ContextVar mode
global_mode = False

# With a global variable, the result is: 1 2 3 3 3 3 3 3 3
# With a ContextVar, the result is:      1 2 3 1 2 3 1 2 3

import asyncio
import contextvars

wch

# This code uses later's C API to schedule callbacks as quickly as possible, and
# it tests if the callbacks execute in the same order that they are scheduled.
# In Docker on Mac, they sometimes do not.

docker run --rm -ti rocker/shiny /bin/bash
R
install.packages(c('cpp11', 'later', 'brio', 'callr', 'cli', 'decor', 'desc',
  'tibble', 'vctrs'))

library(cpp11)

wch

docker run --rm -ti --security-opt seccomp=unconfined wch1/r-debug

# =====================================================================
# Setup
# =====================================================================
RD -e 'install.packages(c("cpp11", "decor", "igraph"))'
RD -e 'remotes::install_github("r-lib/memtools", build_manual = FALSE, build_vignettes = FALSE)'


# ==============================================================================

wch

Keybase proof

I hereby claim:

• I am wch on github.
• I am winston (https://keybase.io/winston) on keybase.
• I have a public key ASBIcD-b7Mr5y30DdA4AfVp_I263JfDKgLboP2DYCHpfvwo

To claim this, I am signing this object:

wch

library(rlang)
library(pryr)

# ===========================
# Normal quosures
# ===========================
# as_function() with a quosure: OK
a <- 1
x <- quo(a + 10)
a <- 2

wch

library(digest)
library(promises)
library(cache)

# Given a list with items named `value` and `visible`, return `x$value` either
# visibly, or invisibly, depending on the value of `x$visible`.
valueWithVisible <- function(x) {
  if (x$visible) x$value else invisible(x$value)
}

wch

library(profvis)
library(microbenchmark)
library(memoise)
library(digest)

# Bare function
f <- function(a, b) {
  a + b
}

wch

library(httpuv)

# Create a web server app which returns the time and prints out the value of
# a header named "test-header".
handle_request <- function(req) {
  list(
    status = 200L,
    headers = list('Content-Type' = 'text/plain'),
    body = paste0(
      "The time is: ", Sys.time(), "\n",