check if we can avoid duplicated code

R/data_modify.R

@@ -177,62 +177,8 @@ data_modify.data.frame <- function(data, ..., .if = NULL, .at = NULL, .modify =
     }
 
     for (i in seq_along(dots)) {
-      # iterate expressions for new variables
-      symbol <- dots[[i]]
-
-      # expression is given as character string in a variable, but named, e.g.
-      # a <- "2 * Sepal.Width"
-      # data_modify(iris, double_SepWidth = a)
-      # we reconstruct the symbol as if it were provided as literal expression.
-      # However, we need to check that we don't have a character vector,
-      # like: data_modify(iris, new_var = "a")
-      # this one should be recycled instead.
-      if (!is.character(symbol)) {
-        eval_symbol <- .dynEval(symbol, ifnotfound = NULL)
-        if (is.character(eval_symbol)) {
-          symbol <- try(str2lang(paste0(names(dots)[i], " = ", eval_symbol)), silent = TRUE)
-          # we may have the edge-case of having a function that returns a character
-          # vector, like "new_var = sample(letters[1:3])". In this case, "eval_symbol"
-          # is of type character, but no symbol, thus str2lang() above creates a
-          # wrong pattern. We then take "eval_symbol" as character input.
-          if (inherits(symbol, "try-error")) {
-            symbol <- str2lang(paste0(
-              names(dots)[i],
-              " = c(", paste0("\"", eval_symbol, "\"", collapse = ","), ")"
-            ))
-          }
-        }
-      }
-
-      # finally, we can evaluate expression and get values for new variables
-      new_variable <- try(with(data, eval(symbol)), silent = TRUE)
-
-      # successful, or any errors, like misspelled variable name?
-      if (inherits(new_variable, "try-error")) {
-        # in which step did error happen?
-        step_number <- switch(as.character(i),
-          "1" = "the first expression",
-          "2" = "the second expression",
-          "3" = "the third expression",
-          paste("expression", i)
-        )
-        step_msg <- paste0("There was an error in ", step_number, ".")
-        # try to find out which variable was the cause for the error
-        error_msg <- attributes(new_variable)$condition$message
-        if (grepl("object '(.*)' not found", error_msg)) {
-          error_var <- gsub("object '(.*)' not found", "\\1", error_msg)
-          insight::format_error(
-            paste0(step_msg, " Variable \"", error_var, "\" was not found in the dataset or in the environment."),
-            .misspelled_string(colnames(data), error_var, "Possibly misspelled or not yet defined?")
-          )
-        } else {
-          insight::format_error(paste0(
-            step_msg, " ", insight::format_capitalize(error_msg),
-            ". Possibly misspelled or not yet defined?"
-          ))
-        }
-      }
-
+      # create new variable
+      new_variable <- .get_new_dots_variable(dots, i, data)
       # give informative error when new variable doesn't match number of rows
       if (!is.null(new_variable) && length(new_variable) != nrow(data) && (nrow(data) %% length(new_variable)) != 0) {
         insight::format_error(