## ----include = FALSE----------------------------------------------------------
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)

## ----setup, echo=FALSE--------------------------------------------------------
library(shiny)
library(dipsaus)
data(ToothGrowth)

## ----eval=FALSE---------------------------------------------------------------
# if ( exists("aa") && !is.null(aa) ) {
#   aa <- 1
# }

## ----eval=TRUE----------------------------------------------------------------
aa %?<-% 1
print(aa)

## -----------------------------------------------------------------------------
l %?<-% list()

l$aa %?<-% 1

print(l)

## -----------------------------------------------------------------------------
# e already exists
e <- list(aa = 1)

# %?<-% will not evaluate rhs, nor assign values
system.time({
  e %?<-% {
    Sys.sleep(10)
    list(aa = 2)
  }
  print(e)
})


## -----------------------------------------------------------------------------
li <- c("A", "T", "G", "C")
li |> iapply(alist(el, ii) %=>% {
  sprintf("The index for %s is %s", el, ii)
})


## -----------------------------------------------------------------------------
alist(a, b = a^2, ...) %=>% {
  print(c(a, b, ...))
}

## -----------------------------------------------------------------------------
match.call(textInput, call = quote(textInput("inputId", "label", "aaa")))

## -----------------------------------------------------------------------------
match.call(tagList, call = quote(tagList(
  div(
    tags$ul(
      tags$li(textInput("inputId", "label", "aaa"))
    )
  )
)))

## -----------------------------------------------------------------------------
match_calls(call = tagList(
  div(
    tags$ul(
      tags$li(textInput("inputId", "label", "aaa"))
    )
  )
), recursive = TRUE)

## -----------------------------------------------------------------------------
match_calls(
  call = tagList(div(tags$ul(
    tags$li(textInput("inputId", "label", "aaa"))
  ))),
  recursive = TRUE,
  replace_args = list(
    "inputId" = function(v, ...) {
      as.call(list(quote(ns), v))
    }
  )
)

## ----eval=FALSE---------------------------------------------------------------
# x_tmp <- x |>
#   do_something(...)
# 
# plot(x_tmp)
# 
# final_results <- x_tmp |>
#   do_others(...)

## ----eval=FALSE---------------------------------------------------------------
# final_results <- x |>
#   do_something(...) |>
#   no_op(plot, ylim = c(0, 100)) |>
#   do_others(...)

## ----fig.width=7,fig.height=5-------------------------------------------------

par(mfrow = c(1, 2))

result <- (1:10) |>
  iapply(alist(el, ii) %=>% {
    rnorm(20, el, ii)
  }, simplify = FALSE) |>
  unlist() |> 
  
  # Begin no-ops, result will not change
  no_op({
    # Use expression and "." to refer the data
    print(summary(.))
  }) |> 
  no_op(
    # Use function and pass ... to function
    plot, x = seq(0, 1, length.out = 200), 
    type = "p", ylim = c(-20, 20), pch = 16,
    xlab = "Time", ylab = "Value", las = 1
  ) |> 
  no_op(hist, xlab = "Values", main = "Histogram") 

str(result)

## -----------------------------------------------------------------------------
ToothGrowth |> 
  do_aggregate(len ~ ., mean)