improve `format_expression`

[chlebowa]

I think we should improve format_expression a little.

Consider:

ll1 <- list(quote(i <- iris), quote(m <- mtcars))
ll2 <- list(quote({i <- iris; m <- mtcars}))
char1 <- c("i <- iris", "m <- mtcars")
char2 <- "
  i <- iris
  m <- mtcars
"

Currently

format_expression <- function(code) {
  code <- lang2calls(code)
  paste(code, collapse = "\n")
}

> format_expression(ll1)
[1] "i <- iris\nm <- mtcars" 
> format_expression(ll2)
[1] "i <- iris\nm <- mtcars"
> format_expression(char1)
[1] "c(\"i <- iris\", \"m <- mtcars\")"
> format_expression(char2)
[1] "\n  i <- iris\n  m <- mtcars\n"

unlist separates character vector

> format_expression <- function(code) {
+   code <- lang2calls(code)
+   paste(unlist(code), collapse = "\n")
+ }

> format_expression(ll1)
[1] "i <- iris\nm <- mtcars"
> format_expression(ll2)
[1] "i <- iris\nm <- mtcars"
> format_expression(char1)
[1] "i <- iris\nm <- mtcars"
> format_expression(char2)
[1] "\n  i <- iris\n  m <- mtcars\n"

trimws removes some excess white space

format_expression <- function(code) {
  code <- lang2calls(code)
  trimws(paste(unlist(code), collapse = "\n"))
}

> format_expression(ll1)
[1] "i <- iris\nm <- mtcars"
> format_expression(ll2)
[1] "i <- iris\nm <- mtcars"
> format_expression(char1)
[1] "i <- iris\nm <- mtcars"
> format_expression(char2)
[1] "i <- iris\n  m <- mtcars"

Question is: do we really need it? This is an internal function and I'm not sure if there are constrains on the input. Then again we may want to use it in another place (there's a PR in teal.data that does).

[m7pr]

@chlebowa is this still relevant? There is no more format_expression in this package and not in teal.data

[chlebowa]

I guess if the answer to "do we need it" is yes, then we should give it some thought. Who knows, maybe even bring back format_expression?

[averissimo]

trimws might mess up some indentation. {styler} might be a good way of getting rid of any formatting issues, but would involve an extra-dependency

format_expression <- function(code) {
  paste(unlist(teal.code:::lang2calls(code)), collapse = "\n")
}

format_expression_trimws <- function(code) {
  trimws(paste(unlist(teal.code:::lang2calls(code)), collapse = "\n"))
}

format_expression_styler <- function(code) {
  paste(styler::style_text(teal.code:::lang2calls(code)), collapse = "\n")
}

char4 <- "
  while (FALSE) {
    i <- iris
    m <- mtcars
  }
"

format_expression(char4)
#> [1] "\n  while (FALSE) {\n    i <- iris\n    m <- mtcars\n  }\n"
format_expression_trimws(char4)
#> [1] "while (FALSE) {\n    i <- iris\n    m <- mtcars\n  }"
format_expression_styler(char4)
#> [1] "while (FALSE) {\n  i <- iris\n  m <- mtcars\n}"

ps. ignore this if there is a downstream formatting I'm missing

[chlebowa]

ps. ignore this if there is a downstream formatting I'm missing

There is, actually:

> teal.widgets::verbatim_popup_srv
function (id, verbatim_content, title, style = FALSE, disabled = shiny::reactiveVal(FALSE)) 
{
    checkmate::assert_string(id)
    checkmate::assert_string(title)
    checkmate::assert_flag(style)
    checkmate::assert_class(disabled, classes = "reactive")
    moduleServer(id, function(input, output, session) {
        ns <- session$ns
        modal_content <- format_content(verbatim_content, style)
        button_click_observer(click_event = shiny::reactive(input$button), 
            copy_button_id = ns("copy_button"), copied_area_id = ns("verbatim_content"), 
            modal_title = title, modal_content = modal_content, 
            disabled = disabled)
    })
}

[gogonzo]

Closing the issue. format_expression doesn't exist anymore. eval_code + get_code seems to return the code asis. If somebody specifies code as character with whitespaces we shouldn't remove them.