Re: [racket-users] Redex: macro expanding to a side-condition clause
Right, so I need a separate metafunction for each pattern I want to negate. On Mon, Oct 24, 2016 at 6:56 PM, Robby Findler wrote: > I am saying to write this: > > (define-metafunction L > [(not-thing pat) #false] > [(not-thing any) #true]) > > and then where you wrote: > > (where/not pat tm) > > write this: > > (where #true (not-thing pat)) > > > > On Mon, Oct 24, 2016 at 5:47 PM, Sam Caldwell wrote: > >> In the meantime, consider using a metafunction with an `else` clause. > > > > This would entail fixing the pattern, right? As in, I can write a > > metafunction deciding whether a term does not match a pattern, but I > can't > > write a metafunction taking both the term and the pattern. > > > > I'm ok with failed matches not being first-class in Redex, but I'm a > little > > disappointed if I can't create my own shorthand. > > > > Thanks, > > Sam Caldwell > > > > On Mon, Oct 24, 2016 at 6:31 PM, Robby Findler < > ro...@eecs.northwestern.edu> > > wrote: > >> > >> Unfortunately, Redex's pattern language does not currently support > >> `not`. It might be easy to add it, or maybe hard, or maybe impossible. > >> Offhand, it seems probably possible to support in the unifier and > >> impossible in the enumerator and not hard in the matcher. > >> > >> In the meantime, consider using a metafunction with an `else` clause. > >> > >> Robby > >> > >> > >> On Mon, Oct 24, 2016 at 5:15 PM, Sam Caldwell wrote: > >> > I have a Redex judgment that I would like to specify in terms of a > >> > *failed* > >> > pattern match. I can write this like so: > >> > > >> > [(side-condition ,(not (redex-match? L pat (term tm))) > >> > -- > >> > ...] > >> > > >> > which works, but I would rather just abbreviate this using a macro > >> > (since > >> > afaict there are no existing constructs in redex to do this), so I > could > >> > write for instance: > >> > > >> > [(where/not pat tm) > >> > -- > >> > ...] > >> > > >> > But then I get an error: "define-judgment-form: expected judgment form > >> > name > >> > in: where/not" > >> > > >> > Does anybody know how to achieve this? > >> > > >> > Thanks, > >> > Sam Caldwell > >> > > >> > Full example: > >> > > >> > == > >> > > >> > #lang racket > >> > > >> > (require redex) > >> > > >> > (define-language L > >> > (E number (+ E E))) > >> > > >> > (define-syntax (where/not stx) > >> > (syntax-case stx () > >> > [(_ pat tm) > >> > #'(side-condition ,(not (redex-match? L pat (term tm])) > >> > > >> > (define-judgment-form L > >> > #:mode (j I) > >> > [(where/not number E) > >> >- > >> >(j E)]) > >> > > >> > -- > >> > You received this message because you are subscribed to the Google > >> > Groups > >> > "Racket Users" group. > >> > To unsubscribe from this group and stop receiving emails from it, send > >> > an > >> > email to racket-users+unsubscr...@googlegroups.com. > >> > For more options, visit https://groups.google.com/d/optout. > > > > > > -- > You received this message because you are subscribed to the Google Groups > "Racket Users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to racket-users+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] Redex: macro expanding to a side-condition clause
I am saying to write this: (define-metafunction L [(not-thing pat) #false] [(not-thing any) #true]) and then where you wrote: (where/not pat tm) write this: (where #true (not-thing pat)) On Mon, Oct 24, 2016 at 5:47 PM, Sam Caldwell wrote: >> In the meantime, consider using a metafunction with an `else` clause. > > This would entail fixing the pattern, right? As in, I can write a > metafunction deciding whether a term does not match a pattern, but I can't > write a metafunction taking both the term and the pattern. > > I'm ok with failed matches not being first-class in Redex, but I'm a little > disappointed if I can't create my own shorthand. > > Thanks, > Sam Caldwell > > On Mon, Oct 24, 2016 at 6:31 PM, Robby Findler > wrote: >> >> Unfortunately, Redex's pattern language does not currently support >> `not`. It might be easy to add it, or maybe hard, or maybe impossible. >> Offhand, it seems probably possible to support in the unifier and >> impossible in the enumerator and not hard in the matcher. >> >> In the meantime, consider using a metafunction with an `else` clause. >> >> Robby >> >> >> On Mon, Oct 24, 2016 at 5:15 PM, Sam Caldwell wrote: >> > I have a Redex judgment that I would like to specify in terms of a >> > *failed* >> > pattern match. I can write this like so: >> > >> > [(side-condition ,(not (redex-match? L pat (term tm))) >> > -- >> > ...] >> > >> > which works, but I would rather just abbreviate this using a macro >> > (since >> > afaict there are no existing constructs in redex to do this), so I could >> > write for instance: >> > >> > [(where/not pat tm) >> > -- >> > ...] >> > >> > But then I get an error: "define-judgment-form: expected judgment form >> > name >> > in: where/not" >> > >> > Does anybody know how to achieve this? >> > >> > Thanks, >> > Sam Caldwell >> > >> > Full example: >> > >> > == >> > >> > #lang racket >> > >> > (require redex) >> > >> > (define-language L >> > (E number (+ E E))) >> > >> > (define-syntax (where/not stx) >> > (syntax-case stx () >> > [(_ pat tm) >> > #'(side-condition ,(not (redex-match? L pat (term tm])) >> > >> > (define-judgment-form L >> > #:mode (j I) >> > [(where/not number E) >> >- >> >(j E)]) >> > >> > -- >> > You received this message because you are subscribed to the Google >> > Groups >> > "Racket Users" group. >> > To unsubscribe from this group and stop receiving emails from it, send >> > an >> > email to racket-users+unsubscr...@googlegroups.com. >> > For more options, visit https://groups.google.com/d/optout. > > -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] Redex: macro expanding to a side-condition clause
> In the meantime, consider using a metafunction with an `else` clause. This would entail fixing the pattern, right? As in, I can write a metafunction deciding whether a term does not match a pattern, but I can't write a metafunction taking both the term and the pattern. I'm ok with failed matches not being first-class in Redex, but I'm a little disappointed if I can't create my own shorthand. Thanks, Sam Caldwell On Mon, Oct 24, 2016 at 6:31 PM, Robby Findler wrote: > Unfortunately, Redex's pattern language does not currently support > `not`. It might be easy to add it, or maybe hard, or maybe impossible. > Offhand, it seems probably possible to support in the unifier and > impossible in the enumerator and not hard in the matcher. > > In the meantime, consider using a metafunction with an `else` clause. > > Robby > > > On Mon, Oct 24, 2016 at 5:15 PM, Sam Caldwell wrote: > > I have a Redex judgment that I would like to specify in terms of a > *failed* > > pattern match. I can write this like so: > > > > [(side-condition ,(not (redex-match? L pat (term tm))) > > -- > > ...] > > > > which works, but I would rather just abbreviate this using a macro (since > > afaict there are no existing constructs in redex to do this), so I could > > write for instance: > > > > [(where/not pat tm) > > -- > > ...] > > > > But then I get an error: "define-judgment-form: expected judgment form > name > > in: where/not" > > > > Does anybody know how to achieve this? > > > > Thanks, > > Sam Caldwell > > > > Full example: > > > > == > > > > #lang racket > > > > (require redex) > > > > (define-language L > > (E number (+ E E))) > > > > (define-syntax (where/not stx) > > (syntax-case stx () > > [(_ pat tm) > > #'(side-condition ,(not (redex-match? L pat (term tm])) > > > > (define-judgment-form L > > #:mode (j I) > > [(where/not number E) > >- > >(j E)]) > > > > -- > > You received this message because you are subscribed to the Google Groups > > "Racket Users" group. > > To unsubscribe from this group and stop receiving emails from it, send an > > email to racket-users+unsubscr...@googlegroups.com. > > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] Redex: macro expanding to a side-condition clause
Unfortunately, Redex's pattern language does not currently support `not`. It might be easy to add it, or maybe hard, or maybe impossible. Offhand, it seems probably possible to support in the unifier and impossible in the enumerator and not hard in the matcher. In the meantime, consider using a metafunction with an `else` clause. Robby On Mon, Oct 24, 2016 at 5:15 PM, Sam Caldwell wrote: > I have a Redex judgment that I would like to specify in terms of a *failed* > pattern match. I can write this like so: > > [(side-condition ,(not (redex-match? L pat (term tm))) > -- > ...] > > which works, but I would rather just abbreviate this using a macro (since > afaict there are no existing constructs in redex to do this), so I could > write for instance: > > [(where/not pat tm) > -- > ...] > > But then I get an error: "define-judgment-form: expected judgment form name > in: where/not" > > Does anybody know how to achieve this? > > Thanks, > Sam Caldwell > > Full example: > > == > > #lang racket > > (require redex) > > (define-language L > (E number (+ E E))) > > (define-syntax (where/not stx) > (syntax-case stx () > [(_ pat tm) > #'(side-condition ,(not (redex-match? L pat (term tm])) > > (define-judgment-form L > #:mode (j I) > [(where/not number E) >- >(j E)]) > > -- > You received this message because you are subscribed to the Google Groups > "Racket Users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to racket-users+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[racket-users] Redex: macro expanding to a side-condition clause
I have a Redex judgment that I would like to specify in terms of a *failed* pattern match. I can write this like so: [(side-condition ,(not (redex-match? L pat (term tm))) -- ...] which works, but I would rather just abbreviate this using a macro (since afaict there are no existing constructs in redex to do this), so I could write for instance: [(where/not pat tm) -- ...] But then I get an error: "define-judgment-form: expected judgment form name in: where/not" Does anybody know how to achieve this? Thanks, Sam Caldwell Full example: == #lang racket (require redex) (define-language L (E number (+ E E))) (define-syntax (where/not stx) (syntax-case stx () [(_ pat tm) #'(side-condition ,(not (redex-match? L pat (term tm])) (define-judgment-form L #:mode (j I) [(where/not number E) - (j E)]) -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
