Am 25.11.2013 15:14, schrieb David A. Wheeler: > On Mon, 25 Nov 2013 12:24:23 +0100, "Jörg F. Wittenberger" > <joerg.wittenber...@softeyes.net> wrote: >> Hi all, >> >> I'm just making my first experiences in actually using srfi-110. >> >> At this point I find myself forced to make serious changes to the >> program logic. Beyond what's supported by simply configuring the source >> code. >> >> The worst thing I found that it will complain on the error port when >> reading badly formatted code and then continue to read. I really, >> really need it to do what other Scheme readers usually do: error out. > Easily done, and there are many ways to do it. > The ONLY procedure that throws an exception is "read-error":
> (define (read-error message) I changed it's signature to match srfi-23 (for know) (: read-error (string &rest * -> *) This allows me to do as better job at error reporting. But I tend to prefer a more restrictive, though compatible, syntax in this case (: read-error (string input-port string &rest * -> *) Whereby I'd require all calls to read-error to pass the port and the last successfully read token in an effort to further improve error messages. But I'm unsure about this. Any comments? > (display "Error: " (current-error-port)) > (display message (current-error-port)) > (newline (current-error-port)) > (flush-output-port (current-error-port)) > (raise 'readable) > '()) > > The ONLY procedure that catches an exception is t-expr-catch: > (define (t-expr-catch port) > (init-sweet) > (guard > (exception > ((eq? exception 'readable) > (read-to-unindented-line port) (t-expr-catch port))) > (t-expr port))) > Is there actually any scheme implementation which benefits from this catching? I can't image. I'd feel it might be good to provide a "clean up read" like `read-to-unindented-line` to help the implementor of a repl. But for the default it just does not feel right to me. /Jörg ------------------------------------------------------------------------------ Shape the Mobile Experience: Free Subscription Software experts and developers: Be at the forefront of tech innovation. Intel(R) Software Adrenaline delivers strategic insight and game-changing conversations that shape the rapidly evolving mobile landscape. Sign up now. http://pubads.g.doubleclick.net/gampad/clk?id=63431311&iu=/4140/ostg.clktrk _______________________________________________ Readable-discuss mailing list Readable-discuss@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/readable-discuss
