Raise error if trying to create empty ranges (#137)

renatahodovan · Oct 3, 2023 · be1fd0f · be1fd0f
1 parent aba79b8
commit be1fd0f
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/grammarinator/tool/processor.py b/grammarinator/tool/processor.py
@@ -278,6 +278,11 @@ class Charset(object):
  _cnt = 0
 
  def __init__(self, ranges):
+ if not ranges:
+ raise ValueError('Charset must contain at least one range')
+ for start, end in ranges:
+ if end <= start:
+ raise ValueError(f"Charset range must not be empty: '\\u{{{start:x}}}'..'\\u{{{end - 1:x}}}', '{chr(start)}'..'{chr(end - 1)}'")
  self.id = Charset._cnt
  Charset._cnt += 1
  self.ranges = ranges