fix rope index (#16100)

* fix rope index * add testcase
2020-11-23 18:27:09 +08:00 · 2020-11-23 18:27:09 +08:00 · ab2c082cb3
commit ab2c082cb3
parent 6a37c0682a
2 changed files with 67 additions and 1 deletions
--- a/lib/pure/ropes.nim
+++ b/lib/pure/ropes.nim
@ -204,8 +204,8 @@ proc `[]`*(r: Rope, i: int): char {.rtl, extern: "nroCharAt".} =
      if x.left.length > j:
        x = x.left
      else:
+        dec(j, x.left.length)
        x = x.right
-        dec(j, x.len)

 iterator leaves*(r: Rope): string =
  ## iterates over any leaf string in the rope `r`.