I think the specification for this problem needs some more information, specifically:
How should implementations behave if the end delimiter is found in the search string before the start delimiter?
Must an error be raised when a delimiter is not present in the search string? Some implementations do this, and some do not.
- This has been clarified. Some implementations will need to be fixed. --Zbentley (talk) 18:00, 6 January 2018 (UTC)
Are null/missing (or equivalent) delimiters allowed?
Are empty-string delimiters allowed? If so, how should they work? Are empty-string start delimiters equivalent to "start" special delims, and empty-string end delimiters equivalent to "end"?
If the start delimiter occurs multiple places in the search string, which one should be used? I think it should be the first occurrence, i.e. both start-search and end-search are eager. --Zbentley (talk) 18:00, 6 January 2018 (UTC)