Re: [Chicken-hackers] a cas of chicken overoptimizing
(define (write-blob-to-sql sql identifier last blob c-c) (define ins '()) (define del '()) (if (vector? blob) (begin (set! ins (vector-ref blob 1)) (set! del (vector-ref blob 2)) (set! blob (vector-ref blob 0 (if (or (pair? ins) (pair? del)) (handle-ins-and-del)) (do-some-more)) handle-ins-and-del used to be reliably executed for at least a year. This is caused by a flow-analysis bug. Compiling with -verbose gives warnings about these two type-checks, so you should enable this option if you assume something's not right. As a quick fix, changing line 645 in scrutinizer.scm to (if #f ...) should get your code running. I will try to provide a proper patch in the meantime. Thanks for reporting this. cheers, felix ___ Chicken-hackers mailing list Chicken-hackers@nongnu.org https://lists.nongnu.org/mailman/listinfo/chicken-hackers
Re: [Chicken-hackers] [PATH] Use hash table instead of flat list for lambda literals
On Feb 13 2012, Peter Bex wrote: On Mon, Feb 13, 2012 at 03:11:05PM -0700, Alan Post wrote: I do think that choice is fine, yes. Does the hash table resize itself when it gets too many entries in it? No, unfortunately these hash tables are pretty basic and too low-level to do such things. Just in case hash table turn out not to be too helpful (and not implying that balanced trees would really help) it might be helpful to have some alternative. Best regards /Jörg (Maybe someone fluent with the egg system could turn this into an egg anyway?) This file should is original name aggregate-chicken.scm http://askemos.org/A5ffdc9d14b6e2dbb899e2240ea8ea99b It implements a hashtable API to LLRB-trees. Two examples: a) LLRB tree indexed by symbols implemented as a pure data structure and b) a tree indexed by strings and updated in place with no additional allocation. The actual implementation is done by this code http://askemos.org/A532a4158b6424c2c2d2b8b5b08d32994 llrbtree.scm (In comment this contains yet one more example: and integer-index tree). The code conditionally expands either to the use of records (for the sake of safety and testing) or direct ##sys#slot references (for speed). This code is actually rather well tested. (As you might have noted I'm running quite some network related code constantly. This used to spell problems with chicken's time queue handling. That's the code, which replaced those linear lists in my chicken. (Amounts to x*10^6 threads a day installing timeouts around their i/o. The symbol and string tables are actually used to implement variable ennvironments.) ___ Chicken-hackers mailing list Chicken-hackers@nongnu.org https://lists.nongnu.org/mailman/listinfo/chicken-hackers
[Chicken-hackers] Thrush operator
Hello Chickeneers, find attached a suggested addition to miscmacros: the thrush operator family. Apparently it stems from Raymond Smullyan's book on combinatorial logic To Mock a Mockingbird, which I haven't read (yet). I've first learned about it through Clojure and have found it quite nice for increasing the readability of chained calls. See Debasish Ghosh's post [1] about it for some background. As a practical example, consider this code: (write (fold + 0 (map (lambda (i) (* 2 i)) (iota 10 Using the thrush operator it can be written like this: (- (iota 10) (map (lambda (i) (* 2 i))) (fold + 0) (write)) which basically expands to the expression above, i.e. it inserts each expression as the last argument of the following expression. I find it much easier to read though since the order of evaluation is the order of appearance in the code. I like to think of it like `let*' as opposed to nested `lambda': ((lambda (x) ((lambda (y) ((lambda (z) (+ x y z)) 3)) 2)) 1) versus: (let* ((x 1) (y 2) (z 3)) (+ x y z)) Much easier to track what's going on there as stuff that belongs together is visually close to each other. There's also `-' which inserts each expression as the first argument of the following one. The difference: (- 10 (- 3)) ; = -7 (- 10 (- 3)) ; = 7 For kicks and fun I also added starred versions (`-*' and `-*') which are multi-value aware. Not sure how useful that is and I didn't want to add it to the default macros to avoid the overhead. But it's good to have them just for completeness sake! I guess that's about it. I'm not sure if adding it to miscmacros is a great idea, might as well just create a `thrush' egg. OTOH we have the similar `doto' macro in there already. Comments? Moritz [1] http://debasishg.blogspot.com/2010/04/thrush-in-clojure.html Index: miscmacros.scm === --- miscmacros.scm (revision 25904) +++ miscmacros.scm (working copy) @@ -9,13 +9,14 @@ define-optionals define-parameter define-enum ignore-values ignore-errors ecase - define-syntax-rule) + define-syntax-rule + - -* - -*) (import scheme) ;; No effect -- caller must import these manually. (import (only chicken when unless handle-exceptions let-optionals make-parameter -add1 sub1)) +add1 sub1 define-for-syntax)) ;;; Modify locations, T-like: @@ -303,4 +304,55 @@ clauses ... (else (error no valid case val +(define-for-syntax (expand-thrush x weave) + (let loop ((y (cdr x)) (form (car x))) +(if (null? y) +form +(let ((z (car y))) + (loop (cdr y) +(weave z form)) + +(define-syntax - + (ir-macro-transformer + (lambda (x i c) + (expand-thrush + (cdr x) + (lambda (z form) +(cons (car z) + (cons form (cdr z + +(define-syntax -* + (ir-macro-transformer + (lambda (x i c) + (expand-thrush + (cdr x) + (lambda (z form) +`(receive args ,form + (apply +,(car z) +(append args (list . ,(cdr z)) + +(define-syntax - + (ir-macro-transformer + (lambda (x i c) + (expand-thrush + (cdr x) + (lambda (z form) +(append z (list form))) + +(define-syntax -* + (ir-macro-transformer + (lambda (x i c) + (expand-thrush + (cdr x) + (lambda (z form) +`(receive args ,form + (apply +,(car z) +(append (list . ,(cdr z)) args + ) + + + + Index: tests/run.scm === --- tests/run.scm (revision 0) +++ tests/run.scm (working copy) @@ -0,0 +1,22 @@ +(use test srfi-1 miscmacros) + +(test 1 (- 99 (/ 11) (/ 9))) + +(test '(1 2 3 4) + (-* (values 1 2) + (list 3) + (append '(4 + +(test 7 (- 10 (- 3))) +(test -7 (- 10 (- 3))) + +(test 9 (- 1 (+ 2) (* 3))) + +(test 9 (- '(1 2 3) + (map add1) + (fold + 0))) + +(test '((foo . 100) (bar . 200)) + (-* (values '(foo bar) '(100 200)) +(map cons))) + ___ Chicken-hackers mailing list Chicken-hackers@nongnu.org https://lists.nongnu.org/mailman/listinfo/chicken-hackers
Re: [Chicken-hackers] Thrush operator
On Feb 14 2012, Moritz Heidkamp wrote: Hello Chickeneers, find attached a suggested addition to miscmacros: the thrush operator family. Apparently it stems from Raymond Smullyan's book on combinatorial logic To Mock a Mockingbird, which I haven't read (yet). I've first learned about it through Clojure and have found it quite nice for increasing the readability of chained calls. See Debasish Ghosh's post [1] about it for some background. Hi Moritz, May I suggest a possibly obvious extension (Long ago I've been playing with similar notations): I rather loved to think instead of inserting the (*single*) value of the expression into the next expression of something along the lines of physical wires: connect (pass) all the result(s) of the first expression into the next (which would then need to accept as many values as the stage before returns. ___ Chicken-hackers mailing list Chicken-hackers@nongnu.org https://lists.nongnu.org/mailman/listinfo/chicken-hackers
Re: [Chicken-hackers] Thrush operator
On 02/14/12 at 10:35pm, Jörg F. Wittenberger wrote: I rather loved to think instead of inserting the (*single*) value of the expression into the next expression of something along the lines of physical wires: A classic, along those lines: http://dkeenan.com/Lambda/ Cheers, Evan ___ Chicken-hackers mailing list Chicken-hackers@nongnu.org https://lists.nongnu.org/mailman/listinfo/chicken-hackers
Re: [Chicken-hackers] Thrush operator
Hi Jörg, Jörg F. Wittenberger joerg.wittenber...@softeyes.net writes: I rather loved to think instead of inserting the (*single*) value of the expression into the next expression of something along the lines of physical wires: connect (pass) all the result(s) of the first expression into the next (which would then need to accept as many values as the stage before returns. if I understand you correctly, this is exactly what the starred versions, `-*' and `-*', do. Or did I get you wrong? Peter had another idea worth considering: using placeholders like `cut' and `cute' do: (- world (list hello ) (string-intersperse ,) (print .)) As this silly example demonstrates this could be used to wire values into arbitrary argument positions. It's a bit more flexible and it may be clearer what's going on but also adds some line noise. I have to think about that! Moritz ___ Chicken-hackers mailing list Chicken-hackers@nongnu.org https://lists.nongnu.org/mailman/listinfo/chicken-hackers
