Automatically unpack dataframes

R/slice-head-tail.R

@@ -10,7 +10,7 @@ slice_head.tidytable <- function(.df, n = 5, ..., .by = NULL, by = NULL) {
 
   dt_env <- get_dt_env(n)
 
-  n <- prep_expr(n)
+  n <- prep_expr(n, .df, dt_env = dt_env)
 
   .by <- tidyselect_names(.df, c({{ .by }}, {{ by }}))
 
@@ -47,7 +47,7 @@ slice_tail.tidytable <- function(.df, n = 5, ..., .by = NULL, by = NULL) {
 
   dt_env <- get_dt_env(n)
 
-  n <- prep_expr(n)
+  n <- prep_expr(n, .df, dt_env = dt_env)
 
   .by <- tidyselect_names(.df, c({{ .by }}, {{ by }}))
 

R/slice.R

@@ -55,7 +55,7 @@ slice.tidytable <- function(.df, ..., .by = NULL) {
 
   dt_env <- get_dt_env(dots)
 
-  dots <- prep_exprs(dots)
+  dots <- prep_exprs(dots, .df, dt_env = dt_env)
 
   .by <- tidyselect_names(.df, {{ .by }})
 

R/utils-prep_exprs.R

@@ -3,17 +3,19 @@
 # Replaces these functions with the necessary data.table translations
 # Adapted from dt_squash found here: https://github.com/tidyverse/dtplyr/blob/master/R/tidyeval.R
 prep_exprs <- function(x, data, .by = NULL, j = FALSE, dt_env = caller_env(), is_top_level = FALSE) {
-  x <- lapply(x, prep_expr, data, {{ .by }}, j = j, dt_env = dt_env, TRUE)
-  list_flatten(x)
+  out <- lapply(x, prep_expr, data, {{ .by }}, j = j, dt_env = dt_env, TRUE)
+  list_flatten(out)
 }
 
 prep_expr <- function(x, data, .by = NULL, j = FALSE, dt_env = caller_env(), is_top_level = FALSE) {
   if (is_quosure(x)) {
     x <- get_expr(x)
   }
 
-  if (is_symbol(x) || is_atomic(x) || is_null(x)) {
+  if (is_atomic(x) || is_null(x)) {
     x
+  } else if (is_symbol(x)) {
+    prep_expr_sym(x, data, dt_env)
   } else if (is_call(x, tidytable_fns)) {
     # Ignore nested calls to tidytable functions, #505
     x
@@ -118,7 +120,24 @@ prep_expr_call <- function(x, data, .by = NULL, j = FALSE, dt_env = caller_env()
     x
   } else {
     # Catches case when "$" or "[[" is used but is not using .data pronoun
-    x[-1] <- lapply(x[-1], prep_expr, data, {{ .by }}, j, dt_env)
+    x
+  }
+}
+
+prep_expr_sym <- function(x, data, dt_env) {
+  data_vars <- names(data)
+  name <- as_string(x)
+  if (name %in% data_vars) {
+    x
+  } else if (env_has(dt_env, name, inherit = TRUE)) {
+    val <- eval_bare(x, dt_env)
+    if (is.data.frame(val)) {
+      out <- list2(!!!val)
+    } else {
+      out <- x
+    }
+    out
+  } else {
     x
   }
 }