CODEWITHSUNDEEP
remacsdata-munging
swihart
swihart

Reputation: 2738

Automatically write readRDS() statements from saveRDS() statements

I often write saveRDS() statements after a good deal of data munging and this prompts me to immediately write readRDS() for future, reproducible coding accessing the .RDS files for faster loading into R. My manual process for generating readRDS() statements from the typed saveRDS() statements is outlined below. How can it be improved? How can I write a macro/function to do this for me, in EMACS and/or R?

## I type these out:
saveRDS(dems,"./_00_data_original/dems.RDS")
saveRDS(meds,"./_00_data_original/meds.RDS")
saveRDS(anti,"./_00_data_original/anti.RDS")

## Then I rectangle kill (C-x-r-k) the file names and commas
## and rectangle yank (C-x-r-y) them on the left hand side
## note:  depends on filenames being equal lengths
dems,saveRDS("./_00_data_original/dems.RDS")
meds,saveRDS("./_00_data_original/meds.RDS")
anti,saveRDS("./_00_data_original/anti.RDS")

## then I Esc-Shift-5 to query replace ",saveRDS" with " <- readRDS"
dems <- readRDS("./_00_data_original/dems.RDS")
meds <- readRDS("./_00_data_original/meds.RDS")
anti <- readRDS("./_00_data_original/anti.RDS")

Upvotes: 4

Views: 1102

Answers (2)

A5C1D2H2I1M1N2O1R2T1
A5C1D2H2I1M1N2O1R2T1

Reputation: 193527

Perhaps you can use something like this:

saveRead <- function(..., path, prefix = "", envir = .GlobalEnv) {
  dots <- substitute(list(...))[-1]
  objs <- sapply(dots, deparse)
  new_objs <- paste0(prefix, objs)
  paths <- file.path(path, paste0(objs, ".RDS"))
  invisible(lapply(seq_along(objs), function(x) {
    saveRDS(get(objs[x], envir = envir), file = paths[x])
    assign(new_objs[x], readRDS(paths[x]), envir = envir)
  }))
}

Here's an example. I'm just writing to a tempdir, but you would enter your actual desired directory. Also, for the sake of demonstration, I've prefixed the object name (on re-read) with "test_". Set prefix to "" (default) to keep the original name.

a <- 1:2
b <- 3:4
ls()
# [1] "a"        "b"        "saveRead"

x <- tempdir()
list.files(x, ".RDS")
# character(0)

saveRead(a, b, path = x, prepend = "test_")
ls()
# [1] "a"        "b"        "saveRead" "test_a"   "test_b"   "x"       
list.files(x, ".RDS")
# [1] "a.RDS" "b.RDS"

To reproduce your actions, it could be used like:

saveRead(dems, meds, anti, path = "./_00_data_original")

Upvotes: 2

Jordon Biondo
Jordon Biondo

Reputation: 4029

Two ways I can think of are using a macro or multiple cursors.

Macro

I often create macros that work on a single line, and the last action of the macro is to move down to the next line, so I can repeat it quickly.

In this case after you copied and pasted the saveRDS blocks, on the first line: begin recording a macro and perform these actions:

  1. goto beginning of line
  2. move forward two words
  3. mark and cut word behind the cursor
  4. erase the comma
  5. goto beginning of line
  6. yank
  7. insert "<- read"
  8. delete the next 4 characters (save)
  9. move down 1 line.
  10. stop recording macro

The key is to record the macro in a way that it will be able to apply genericaly to all lines with the given format. Making sure lines where the filename is something like "foo-bar baz" can be transformed by the macro as well as simple filenames like "bar" by using things like forward-word or forward-sexp instead of moving character by character.

Then you can use C-xe to run the macro, on the next line, and just press e to run it again on the next lines until done. You use a prefix argument too, so if you know you want to apply it to 10 lines, then you can use C-u10C-xe

Here I record the macro on the first line, wait a second, then quickly apply it to both lines below.

enter image description here

You can save this macro in your init by using name-last-kbd-macro and insert-kbd-macro and use it like a command in future sessions.

Multiple Cursors

Or you can use multiple cursors, this will allow you to perform the same action as the macro, but on all the lines at the same time.

https://github.com/magnars/multiple-cursors.el

enter image description here

Upvotes: 4

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