read_lines() warning message and the problems() function

[mrhumanzee]

I'm working with the binary object casetable_bin. When I tried to parse this object into a string vector using the command casetable_lines <- read_lines(casetable_bin), I received the following warning message:

One or more parsing issues, call problems() on your data frame for details, e.g.:
dat <- vroom(...)
problems(dat)

However, running the command readr::problems(casetable_lines) returns nothing. Furthermore, running the command attributes(casetable_lines) returns only the NULL value. Where does readr store the problems it detects in objects?

[hadley]

Can you please provide a minimal reprex (reproducible example)? The goal of a reprex is to make it as easy as possible for me to recreate your problem so that I can fix it: please help me help you! If you've never heard of a reprex before, start by reading about the reprex package, including the advice further down the page. Please make sure your reprex is created with the reprex package as it gives nicely formatted output and avoids a number of common pitfalls.

[mrhumanzee]

Can you please provide a minimal reprex (reproducible example)? The goal of a reprex is to make it as easy as possible for me to recreate your problem so that I can fix it: please help me help you! If you've never heard of a reprex before, start by reading about the reprex package, including the advice further down the page. Please make sure your reprex is created with the reprex package as it gives nicely formatted output and avoids a number of common pitfalls.

# Load 'readr'
library(readr)

# Create an empty vector to store each unique ASCII character
ascii_vector <- raw(128)

# Fill the vector with ASCII characters using a loop
for (i in 0:127) {
  ascii_vector[i + 1] <- as.raw(i)
}

# Print the vector
print(ascii_vector)
#>   [1] 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f 10 11 12 13 14 15 16 17 18
#>  [26] 19 1a 1b 1c 1d 1e 1f 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f 30 31
#>  [51] 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f 40 41 42 43 44 45 46 47 48 49 4a
#>  [76] 4b 4c 4d 4e 4f 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f 60 61 62 63
#> [101] 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f 70 71 72 73 74 75 76 77 78 79 7a 7b 7c
#> [126] 7d 7e 7f


# The function 'read_lines()' returns a warning message: 
read_lines(ascii_vector)
#> Warning: One or more parsing issues, call `problems()` on your data frame for details,
#> e.g.:
#>   dat <- vroom(...)
#>   problems(dat)
#> [1] ""


# Calling the function 'problems()' returns nothing
readr::problems(ascii_vector) 
attributes(ascii_vector) 
#> NULL
Ā
#> Error in eval(expr, envir, enclos): object 'Ā' not found

^{Created on 2023-07-31 with reprex v2.0.2}

Interestingly, when I run this code without reprex, I do not get Ā followed by #> Error in eval(expr, envir, enclos): object 'Ā' not found.

[hadley]

Thanks! Here's a somewhat more minimal reprex:

library(readr)

ascii_vector <- raw(128)
for (i in 0:127) {
  ascii_vector[i + 1] <- as.raw(i)
}

out <- read_lines(ascii_vector)
#> Warning: One or more parsing issues, call `problems()` on your data frame for details,
#> e.g.:
#>   dat <- vroom(...)
#>   problems(dat)
problems(out) 

^{Created on 2023-07-31 with reprex v2.0.2}

[mrhumanzee]

I forgot to store the output to read_lines() in my reprex, my bad! However, it appears the problem is demonstrated in the example you give.