[RFC][DISCUSSION] Context Sensitive lexer

Hi internals, I'd like to put the "Context Sensitive Lexer" RFC into discussion phase: RFC: https://wiki.php.net/rfc/context_sensitive_lexer TL;DR commit: https://github.com/marcioAlmada/php-src/commit/c01014f9 PR: https://github.com/php/php-src/pull/1054 PHP currently has ~64 globally reserved words. Not infrequently, these reserved words end up clashing with legit alternatives to userland API declarations. This RFC proposes minimal changes to have a context sensitive lexer with support for semi-reserved words on PHP7 without causing maintenance issues. This could be especially useful to: - Reduce the surface of BC breaks whenever new keywords are introduced - Avoid restricting userland APIs. Dispensing the need for hacks like unecessary magic method calls or prefixed identifiers. The patch is 98% finished, the entire test suite is passing. I'm still adding more tests to it but the hard part is done. So it's time to discuss! Sincerely, Márcio Almada