Option to match end before any patterns

There is persistent problem with injected languages where unclosed parentheses or quotes eat whole document.

I'm proposing to add option e.g. applyEndPatternFirst. This would check such end pattern at every line before anything else. I've looked at code a bit and it seems possible, but I'm not familiar enough with engine to correctly implement this (at least without trashing performance).

Details:

• On end match - everything before end would be extracted and checked again with sub-patterns and merged with end's tokens, while rest of line would be checked normally. Without match - business as usual.
• When multiple end patterns with this option will be present, they should be stored and checked from first to last, at every line until any of them matches. There shouldn't be too many of them, since this should be used mainly with injected languages.
• Successful match will terminate all descendant rules, after matching "before end" part of line.
• end with option should also match in line where before was found.

Why not use while? While while (sic) is great addition, it can only exclude whole line. Proposed option would allow stopping in mid-line.

Start by locating the tokenizer engine and its handling of TextMate grammar end patterns; the issue does not name a file or test. Trace injected-language termination and performance implications, then define tests for mid-line termination, nested rules, multiple end patterns, and matching on the line containing before.