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Re: regexp and valid-sre?

This page is part of the web mail archives of SRFI 115 from before July 7th, 2015. The new archives for SRFI 115 contain all messages, not just those from before July 7th, 2015.

On 11/26/2013 1:46 PM, Arthur A. Gleckler wrote:
On Tue, Nov 26, 2013 at 1:29 PM, Michael Montague <mikemon@xxxxxxxxx> wrote:
I just briefly looked through the documentation for GNU Emacs and could not find the equivalent of  'valid-sre?'.
Much of that code is written in C.  It would clearly be useful to be able to give a user an error message about having typed an invalid regular _expression_ when using `re-search-forward', for example.
Why does it matter if the code is written in C or Scheme? The code that calls re-search-forward can use guard to catch the exception raised by an invalid regular _expression_. Why were exceptions put into R7RS if we are not going to use them? Is the issue that 'valid-sre?' predates portable support for exception handling in Scheme?