outsource computation of token_to_update. Introduce a zero_ref.

Author: lorenzwalthert

R/reindent.R

@@ -91,15 +91,14 @@ apply_ref_indention <- function(flattened_pd) {
 #' @param target_token The index of the token from which the indention level
 #'   should be applied to other tokens.
 apply_ref_indention_one <- function(flattened_pd, target_token) {
-  token_points_to_ref <-
-    flattened_pd$indention_ref_pos_id == flattened_pd$pos_id[target_token]
-  first_token_on_line <- flattened_pd$lag_newlines > 0L
-  token_to_update <- which(token_points_to_ref & first_token_on_line)
 
+  token_to_update <- find_tokens_to_update(flattened_pd, target_token)
   # udate spaces
   copied_spaces <- flattened_pd$col2[target_token]
   old_spaces <- flattened_pd$lag_spaces[token_to_update[1]]
-  shift <- copied_spaces - old_spaces
+  if (length(token_to_update) < 1) return(flattened_pd)
+  zero_ref <- min(flattened_pd$lag_spaces[token_to_update])
+  shift <-  copied_spaces - zero_ref
   flattened_pd$lag_spaces[token_to_update] <-
     flattened_pd$lag_spaces[token_to_update] + shift
 
@@ -110,6 +109,34 @@ apply_ref_indention_one <- function(flattened_pd, target_token) {
   flattened_pd
 }
 
+#' Find the tokens to update when applying a reference indention
+#'
+#' Given a target token and a flattened parse table, the token for which the
+#' spacing information needs to be updated are computed. Since indention is
+#' already embeded in the column `lag_spaces`, only tokens at the beginning of
+#' a line are of concern.
+#' This function is currently tailored targeted at
+#' re-indention of function delcaration.
+#' @param flattened_pd A flattened parse table.
+#' @param token_to_update An integer vector with positions of tokens to update.
+#' @seealso apply_ref_indention_one()
+#' @examples
+#' style_text("function(a =
+#'   b,
+#'   dd
+#' ) {}", scope = "indention")
+#' style_text("function(a,
+#'   b,
+#'   dd
+#' ) {}", scope = "indention")
+find_tokens_to_update <- function(flattened_pd, target_token) {
+  token_points_to_ref <-
+    flattened_pd$indention_ref_pos_id == flattened_pd$pos_id[target_token]
+  first_token_on_line <- flattened_pd$lag_newlines > 0L
+  which(token_points_to_ref & first_token_on_line)
+}
+
+
 #' Set indention of tokens that match regex
 #'
 #' Force the level of indention of tokens whose text matches a regular