Re: Attaching an alist to a grob
Am 14.01.2015 um 14:47 schrieb Mattes: Am Mittwoch, 14. Januar 2015 13:56 CET, Urs Liska u...@openlilylib.org schrieb: OK, I see. But somehow it feels wrong that #(display annotation? some-obj) doesn't produce #t but the content of location. Should I ignore that feeling? If you intended to write #(display (annotation? some-obj)) Oops, yes, that's what I intended to write in the above message. Of course that's not what I'd write in real code where I'd only need #(if (annotation? some-obj)). then, yes, ignore that feeling. Scheme, like all Lisps (that I know of) has generalized booleans, so anything that's not explicitly false [1] is considered true. Because of this you hardly ever see a litteral #t in Scheme code. OK. I'll try to internalize this, and of course I'll update the code ASAP. Thanks again for the different input Urs Cheers, RalfD [1] while Scheme considers #f to be the only _false_ value, Common Lisp et al. also consider the empty list '() as a valse value. Urs ___ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user
Re: Attaching an alist to a grob
Am 14.01.2015 um 04:08 schrieb Paul Morris: Urs Liska wrote Now I've checked - it's perfect. Thank you again! There is no alist? predicate, but it's very easy to define: #(define (alist? lst) (and (list? lst) (every pair? lst))) Glad to help and glad someone else is benefiting from this. (On a related note, I also worked out how to create custom context properties if that's ever useful.) Currently this doesn't ring a bell with me but I can imagine I'll come back to this one day. Hey, look at you slinging that Scheme like it was nothing! ;-) Yes, I made some surprising progress with Scheme recently. I didn't even get stuck in the ands and parens in the actual predicate I wrote #(define (annotation? obj) (and (and (list? obj) (every pair? obj)) (and (if (assoc-ref obj type) #t #f) (if (assoc-ref obj location) #t #f :-) Unfortunately that does *not* mean there are no huge mysteries left ... Urs Cheers, -Paul -- View this message in context: http://lilypond.1069038.n5.nabble.com/Attaching-an-alist-to-a-grob-tp170412p170434.html Sent from the User mailing list archive at Nabble.com. ___ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user ___ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user
Re: Attaching an alist to a grob
Am 14.01.2015 um 11:18 schrieb Mattes: Am Mittwoch, 14. Januar 2015 09:42 CET, Urs Liska u...@openlilylib.org schrieb: Yes, I made some surprising progress with Scheme recently. I didn't even get stuck in the ands and parens in the actual predicate I wrote #(define (annotation? obj) (and (and (list? obj) (every pair? obj)) (and (if (assoc-ref obj type) #t #f) (if (assoc-ref obj location) #t #f Proper indentation helps ;-) But why so contrived? Your code is equivalent to: #(define (annotation? obj) (and (list? obj) (every pair? obj) (if (assoc-ref obj type) #t #f) (if (assoc-ref obj location) #t #f))) HTH Ralf Mattes Thanks, this is of course better. sorting out nested conditionals has never been my strongest point ;-) Urs ___ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user
Re: Attaching an alist to a grob
On Wed, 2015-01-14 at 12:34 +0100, Urs Liska wrote: Am 14.01.2015 um 12:28 schrieb Richard Shann: On Wed, 2015-01-14 at 11:29 +0100, Urs Liska wrote: Am 14.01.2015 um 11:18 schrieb Mattes: Am Mittwoch, 14. Januar 2015 09:42 CET, Urs Liska u...@openlilylib.org schrieb: Yes, I made some surprising progress with Scheme recently. I didn't even get stuck in the ands and parens in the actual predicate I wrote #(define (annotation? obj) (and (and (list? obj) (every pair? obj)) (and (if (assoc-ref obj type) #t #f) (if (assoc-ref obj location) #t #f Proper indentation helps ;-) But why so contrived? Your code is equivalent to: #(define (annotation? obj) (and (list? obj) (every pair? obj) (if (assoc-ref obj type) #t #f) (if (assoc-ref obj location) #t #f))) ... and is this just equivalent to: #(define (annotation? obj) (and (list? obj) (every pair? obj) (assoc-ref obj type) (assoc-ref obj location))) ??? I don't think so because the result of the function would be the result of the last expression. yes, and in Scheme all expressions except #f are true. (That's why #t is used so rarely, because it is just an empty symbol, used when you haven't got anything else.) Richard assoc-ref returns the value to the key, so if passed a valid object the result of the predicate wouldn't be #t but the content of location. That's why I enclosed these checks in if constructs. Urs Richard HTH Ralf Mattes Thanks, this is of course better. sorting out nested conditionals has never been my strongest point ;-) Urs ___ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user ___ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user
Re: Attaching an alist to a grob
On Wed, 2015-01-14 at 11:29 +0100, Urs Liska wrote: Am 14.01.2015 um 11:18 schrieb Mattes: Am Mittwoch, 14. Januar 2015 09:42 CET, Urs Liska u...@openlilylib.org schrieb: Yes, I made some surprising progress with Scheme recently. I didn't even get stuck in the ands and parens in the actual predicate I wrote #(define (annotation? obj) (and (and (list? obj) (every pair? obj)) (and (if (assoc-ref obj type) #t #f) (if (assoc-ref obj location) #t #f Proper indentation helps ;-) But why so contrived? Your code is equivalent to: #(define (annotation? obj) (and (list? obj) (every pair? obj) (if (assoc-ref obj type) #t #f) (if (assoc-ref obj location) #t #f))) ... and is this just equivalent to: #(define (annotation? obj) (and (list? obj) (every pair? obj) (assoc-ref obj type) (assoc-ref obj location))) ??? Richard HTH Ralf Mattes Thanks, this is of course better. sorting out nested conditionals has never been my strongest point ;-) Urs ___ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user ___ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user
Re: Attaching an alist to a grob
Am 14.01.2015 um 12:28 schrieb Richard Shann: On Wed, 2015-01-14 at 11:29 +0100, Urs Liska wrote: Am 14.01.2015 um 11:18 schrieb Mattes: Am Mittwoch, 14. Januar 2015 09:42 CET, Urs Liska u...@openlilylib.org schrieb: Yes, I made some surprising progress with Scheme recently. I didn't even get stuck in the ands and parens in the actual predicate I wrote #(define (annotation? obj) (and (and (list? obj) (every pair? obj)) (and (if (assoc-ref obj type) #t #f) (if (assoc-ref obj location) #t #f Proper indentation helps ;-) But why so contrived? Your code is equivalent to: #(define (annotation? obj) (and (list? obj) (every pair? obj) (if (assoc-ref obj type) #t #f) (if (assoc-ref obj location) #t #f))) ... and is this just equivalent to: #(define (annotation? obj) (and (list? obj) (every pair? obj) (assoc-ref obj type) (assoc-ref obj location))) ??? I don't think so because the result of the function would be the result of the last expression. assoc-ref returns the value to the key, so if passed a valid object the result of the predicate wouldn't be #t but the content of location. That's why I enclosed these checks in if constructs. Urs Richard HTH Ralf Mattes Thanks, this is of course better. sorting out nested conditionals has never been my strongest point ;-) Urs ___ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user ___ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user
Re: Attaching an alist to a grob
Am Mittwoch, 14. Januar 2015 12:34 CET, Urs Liska u...@openlilylib.org schrieb: #(define (annotation? obj) (and (list? obj) (every pair? obj) (if (assoc-ref obj type) #t #f) (if (assoc-ref obj location) #t #f))) ... and is this just equivalent to: #(define (annotation? obj) (and (list? obj) (every pair? obj) (assoc-ref obj type) (assoc-ref obj location))) ??? I don't think so because the result of the function would be the result of the last expression. assoc-ref returns the value to the key, so if passed a valid object the result of the predicate wouldn't be #t but the content of location. That's why I enclosed these checks in if constructs. Richard is right, the if-clauses aren't neccessary. Scheme has the concept generalized booleans, i.e. anything that isn't explicitly false is considered to be true: guile (if 42 'true 'false) I was just trying to keep as much of your code as possible Cheers, RalfD ___ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user
Re: Attaching an alist to a grob
Am Mittwoch, 14. Januar 2015 13:56 CET, Urs Liska u...@openlilylib.org schrieb: OK, I see. But somehow it feels wrong that #(display annotation? some-obj) doesn't produce #t but the content of location. Should I ignore that feeling? If you intended to write #(display (annotation? some-obj)) then, yes, ignore that feeling. Scheme, like all Lisps (that I know of) has generalized booleans, so anything that's not explicitly false [1] is considered true. Because of this you hardly ever see a litteral #t in Scheme code. Cheers, RalfD [1] while Scheme considers #f to be the only _false_ value, Common Lisp et al. also consider the empty list '() as a valse value. Urs ___ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user
Re: Attaching an alist to a grob
Am 14.01.2015 um 12:42 schrieb Mattes: Am Mittwoch, 14. Januar 2015 12:34 CET, Urs Liska u...@openlilylib.org schrieb: #(define (annotation? obj) (and (list? obj) (every pair? obj) (if (assoc-ref obj type) #t #f) (if (assoc-ref obj location) #t #f))) ... and is this just equivalent to: #(define (annotation? obj) (and (list? obj) (every pair? obj) (assoc-ref obj type) (assoc-ref obj location))) ??? I don't think so because the result of the function would be the result of the last expression. assoc-ref returns the value to the key, so if passed a valid object the result of the predicate wouldn't be #t but the content of location. That's why I enclosed these checks in if constructs. Richard is right, the if-clauses aren't neccessary. Scheme has the concept generalized booleans, i.e. anything that isn't explicitly false is considered to be true: guile (if 42 'true 'false) I was just trying to keep as much of your code as possible Cheers, RalfD OK, I see. But somehow it feels wrong that #(display annotation? some-obj) doesn't produce #t but the content of location. Should I ignore that feeling? Urs ___ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user
Re: Attaching an alist to a grob
Urs Liska wrote Now I've checked - it's perfect. Thank you again! There is no alist? predicate, but it's very easy to define: #(define (alist? lst) (and (list? lst) (every pair? lst))) Glad to help and glad someone else is benefiting from this. (On a related note, I also worked out how to create custom context properties if that's ever useful.) Hey, look at you slinging that Scheme like it was nothing! ;-) Cheers, -Paul -- View this message in context: http://lilypond.1069038.n5.nabble.com/Attaching-an-alist-to-a-grob-tp170412p170434.html Sent from the User mailing list archive at Nabble.com. ___ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user
Re: Attaching an alist to a grob
Urs Liska wrote So does anyone have an idea how I can attach an alist to a grob so that an engraver can retrieve it? Is it for example possible to add an arbitrary property to a grob? Hi Urs, I've had good luck creating custom grob properties, which sounds like what you're looking for. Here's how I do it, with some example custom properties that I use: %% CUSTOM GROB PROPERTIES %% I use cn- to keep my functions separate from standard %% LilyPond functions (like a poor man's namespace). % function from scm/define-grob-properties.scm (modified) #(define (cn-define-grob-property symbol type?) (set-object-property! symbol 'backend-type? type?) (set-object-property! symbol 'backend-doc custom grob property) symbol) #(cn-define-grob-property 'cn-is-clairnote-staff boolean?) #(cn-define-grob-property 'cn-vscale-staff number?) Once they are defined I can use the custom properties with any grob (e.g. StaffSymbol): \override StaffSymbol.cn-is-clairnote-staff = ##t \override StaffSymbol.cn-vscale-staff = #1.2 I suppose for an alist you would just use list? as the type predicate (or maybe there's one for alists?). Cheers, -Paul -- View this message in context: http://lilypond.1069038.n5.nabble.com/Attaching-an-alist-to-a-grob-tp170412p170416.html Sent from the User mailing list archive at Nabble.com. ___ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user
Re: Attaching an alist to a grob
Paul Morris wrote %% I use cn- to keep my functions separate from standard %% LilyPond functions (like a poor man's namespace). Well, I should have said functions, custom property names, etc. separate... -Paul -- View this message in context: http://lilypond.1069038.n5.nabble.com/Attaching-an-alist-to-a-grob-tp170412p170417.html Sent from the User mailing list archive at Nabble.com. ___ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user
Re: Attaching an alist to a grob
Hi Paul, thanks for that. Will have to try that out later today, but indeed it looks exactly like what I'm looking for. I think I can soon give back the results :-) Best Urs Am 13. Januar 2015 20:45:31 MEZ, schrieb Paul Morris p...@paulwmorris.com: Urs Liska wrote So does anyone have an idea how I can attach an alist to a grob so that an engraver can retrieve it? Is it for example possible to add an arbitrary property to a grob? Hi Urs, I've had good luck creating custom grob properties, which sounds like what you're looking for. Here's how I do it, with some example custom properties that I use: %% CUSTOM GROB PROPERTIES %% I use cn- to keep my functions separate from standard %% LilyPond functions (like a poor man's namespace). % function from scm/define-grob-properties.scm (modified) #(define (cn-define-grob-property symbol type?) (set-object-property! symbol 'backend-type? type?) (set-object-property! symbol 'backend-doc custom grob property) symbol) #(cn-define-grob-property 'cn-is-clairnote-staff boolean?) #(cn-define-grob-property 'cn-vscale-staff number?) Once they are defined I can use the custom properties with any grob (e.g. StaffSymbol): \override StaffSymbol.cn-is-clairnote-staff = ##t \override StaffSymbol.cn-vscale-staff = #1.2 I suppose for an alist you would just use list? as the type predicate (or maybe there's one for alists?). Cheers, -Paul -- View this message in context: http://lilypond.1069038.n5.nabble.com/Attaching-an-alist-to-a-grob-tp170412p170416.html Sent from the User mailing list archive at Nabble.com. ___ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user ___ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user
Re: Attaching an alist to a grob
Am 13.01.2015 um 21:41 schrieb Urs Liska: Hi Paul, thanks for that. Will have to try that out later today, but indeed it looks exactly like what I'm looking for. I think I can soon give back the results :-) Now I've checked - it's perfect. Thank you again! There is no alist? predicate, but it's very easy to define: #(define (alist? lst) (and (list? lst) (every pair? lst))) Best Urs Best Urs Am 13. Januar 2015 20:45:31 MEZ, schrieb Paul Morris p...@paulwmorris.com: Urs Liska wrote So does anyone have an idea how I can attach an alist to a grob so that an engraver can retrieve it? Is it for example possible to add an arbitrary property to a grob? Hi Urs, I've had good luck creating custom grob properties, which sounds like what you're looking for. Here's how I do it, with some example custom properties that I use: %% CUSTOM GROB PROPERTIES %% I use cn- to keep my functions separate from standard %% LilyPond functions (like a poor man's namespace). % function from scm/define-grob-properties.scm (modified) #(define (cn-define-grob-property symbol type?) (set-object-property! symbol 'backend-type? type?) (set-object-property! symbol 'backend-doc custom grob property) symbol) #(cn-define-grob-property 'cn-is-clairnote-staff boolean?) #(cn-define-grob-property 'cn-vscale-staff number?) Once they are defined I can use the custom properties with any grob (e.g. StaffSymbol): \overrideStaffSymbol.cn http://StaffSymbol.cn-is-clairnote-staff = ##t \overrideStaffSymbol.cn http://StaffSymbol.cn-vscale-staff = #1.2 I suppose for an alist you would just use list? as the type predicate (or maybe there's one for alists?). Cheers, -Paul -- View this message in context:http://lilypond.1069038.n5.nabble.com/Attaching-an-alist-to-a-grob-tp170412p170416.html Sent from the User mailing list archive atNabble.com http://Nabble.com. lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user ___ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user ___ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user
