EQ_FORMALS can cause indention in eq_sub()

needs_indention.*() takes an additional argument other_trigger_tokens which is used to determine whether a trigger causes indention. The new criteria is that (1) there is no multi-line token between the trigger and the first line break and (2) there is no other token between the potential trigger and the first line break that is going to cause indention. Aims to solve #352 and #351.

Author: lorenzwalthert

R/indent.R

@@ -19,7 +19,8 @@ indent_braces <- function(pd, indent_by) {
   set_unindention_child(pd, token = "')'", unindent_by = indent_by)
 }
 
-#' @describeIn update_indention Indents operators
+#' @describeIn update_indention Indents *all* tokens after `token` - including
+#'   the last token.
 indent_op <- function(pd,
                       indent_by,
                       token = c(
@@ -36,12 +37,14 @@ indent_op <- function(pd,
 }
 
 #' @describeIn update_indention Updates indention for token EQ_SUB. Only differs
-#'   from indent_op in the sense that the last token on the table where EQ_SUB
+#'   from [indent_op()] in the sense that not all subsequent tokens in the parse
+#'   table are necessarily indented, as `EQ_SUB` and `EQ_FORMALS` can occur
+#'   multiple times in a parse table.
 #'   occurs is not indented (see[compute_indent_indices()])
 indent_eq_sub <- function(pd,
                           indent_by,
-                          token = "EQ_SUB") {
-  eq_sub <- which(pd$token == "EQ_SUB")
+                          token = c("EQ_SUB", "EQ_FORMALS")) {
+  eq_sub <- which(pd$token %in% token)
   if (length(eq_sub) == 0) return(pd)
   has_line_break <- which(pd$lag_newlines > 0)
   indent_indices <- intersect(eq_sub + 1, has_line_break)
@@ -126,7 +129,9 @@ compute_indent_indices <- function(pd,
                                    token_closing = NULL) {
   npd <- nrow(pd)
   potential_triggers <- which(pd$token %in% token_opening)
-  needs_indention <- needs_indention(pd, potential_triggers)
+  needs_indention <- needs_indention(
+    pd, potential_triggers, other_trigger_tokens = c("EQ_SUB", "EQ_FORMALS")
+  )
   trigger <- potential_triggers[needs_indention][1]
   if (is.na(trigger)) return(numeric(0))
   start <- trigger + 1
@@ -147,25 +152,52 @@ compute_indent_indices <- function(pd,
 #' @param potential_triggers A vector with indices of the potential trigger
 #'   tokens in `pd`.
 #' @inheritParams needs_indention_one
-needs_indention <- function(pd, potential_triggers) {
-  map_lgl(potential_triggers, needs_indention_one, pd = pd)
+needs_indention <- function(pd,
+                            potential_triggers_pos,
+                            other_trigger_tokens = NULL) {
+  map_lgl(potential_triggers_pos, needs_indention_one,
+    pd = pd, other_trigger_tokens = other_trigger_tokens
+  )
 }
 
 
 #' Check whether indention is needed
 #'
-#' Indention is needed if and only if there is no multi-line token between the
-#' trigger and the first line break.
+#' Indention is needed if the two conditions apply:
+#'
+#' * there is no multi-line token between the trigger and the first line break.
+#' * there is no other token between the potential trigger and the first line
+#'   break that is going to cause indention.
+#'
 #' @param pd A parse table.
 #' @param potential_trigger the index of the token in the parse table
 #'   for which it should be checked whether it should trigger indention.
 #' @return Returns `TRUE` if indention is needed, `FALSE` otherwise.
+#' @param other_trigger_tokens Other tokens that are going to cause indention
+#'   if on the same line as the token corresponding to `potential_trigger`.
 #' @return `TRUE` if indention is needed, `FALSE` otherwise.
 #' @importFrom rlang seq2
-needs_indention_one <- function(pd, potential_trigger) {
+needs_indention_one <- function(pd,
+                                potential_trigger_pos,
+                                other_trigger_tokens) {
   before_first_break <- which(pd$lag_newlines > 0)[1] - 1
   if (is.na(before_first_break)) return(FALSE)
-  !any(pd$multi_line[seq2(potential_trigger, before_first_break)])
+  row_idx_between_trigger_and_line_break <- seq2(
+    potential_trigger_pos, before_first_break
+  )
+  multi_line_token <- pd_is_multi_line(
+    pd[row_idx_between_trigger_and_line_break,]
+  )
+  remaining_row_idx_between_trigger_and_line_break <- setdiff(
+    row_idx_between_trigger_and_line_break,
+    potential_trigger_pos
+  )
+
+  other_trigger_on_same_line <-
+    pd[remaining_row_idx_between_trigger_and_line_break,]$token %in%
+      other_trigger_tokens
+
+  !any(multi_line_token) & !any(other_trigger_on_same_line)
 }