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repl and macros
by Jörg F. Wittenberger 11 Avr '20

11 Avr '20

Hi, yet another gambit newbee question. From lambdanative console template I learned how to start a `repl` in a statically linked binary. (N.B. "statically linked" MAY be boring; maybe not.) The pattern is: (define (repl-loop) (with-exception-catcher (lambda (exn) (DISPLAY-EXCEPTION)) ##repl-debug) (repl-loop)) (repl-loop) Use of `define-macro` as input yields "Ill-placed define-macro" exception. Thanks /Jörg

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output ports created with ##open-predefined not being garbage collected
by santana＠mailbox.org 11 Avr '20

11 Avr '20

Was fiddling with gambit's c-ffi and noticed that wills I attached to ports made with ##open-predefined weren't executing so I wrote some test code, if there's something wrong with my code please let me know. # cat fdes.scm (c-declare #<<c-declare-end #include <sys/stat.h> #include <fcntl.h> #include <unistd.h> c-declare-end ) (define-macro (c-macro var) `(define ,var ((c-lambda () int ,(string-append "___return(" (symbol->string var) ");"))))) ;; posix open flags (c-macro O_RDONLY) (c-macro O_WRONLY) (c-macro O_RDWR) (c-macro O_CREAT) ;; filename flags mode -> fdes | -1 (define posix-open (c-lambda (nonnull-char-string int int) int "open")) ;; fdes -> 0 | -1 (define posix-close (c-lambda (int) int "close")) (define in 1) (define out 2) (define inout 3) ;;; ;;; The will only executes if direction is in (define (test-posix-open filename direction) (let* ((fd (case direction ((1) (posix-open filename (bitwise-ior O_RDONLY O_CREAT) #o755)) ((2) (posix-open filename (bitwise-ior O_WRONLY O_CREAT) #o755)) ((3) (posix-open filename (bitwise-ior O_RDWR O_CREAT) #o755)))) (port (##open-predefined direction filename fd))) (println "fd: " fd " port: " port) (make-will port (lambda (p) (println "[WILL] closing port " p) (posix-close fd)))) (##gc)) ;;; when run with direction other than in this eats up all my ram (define (test-loop filename direction) (let ((fd (case direction ((1) (posix-open filename (bitwise-ior O_RDONLY O_CREAT) #o755)) ((2) (posix-open filename (bitwise-ior O_WRONLY O_CREAT) #o755)) ((3) (posix-open filename (bitwise-ior O_RDWR O_CREAT) #o755))))) (let loop () (##open-predefined direction filename fd) (loop))))

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Re: [gambit-list] Universal backend progress
by Ben 07 Avr '20

07 Avr '20

Hi > The universal backend is sufficiently feature-full to compile the gsi interpreter and builtin modules and support the module system and dynamically loading compiled modules: Wow thats great, I very much looked forward to this! The js target runs fine on my machine, the python target not: % gsi/gsi-python lib/ _test/test gsi/gsi-python lib/ _test/test Traceback (most recent call last): File "gsi/gsi-python", line 983046, in <module> g_module_register([[g_make_interned_symbol("_gambit")],[],g_null_obj,1,g_bb1___gambit_23_,False]) File "gsi/gsi-python", line 744, in g_module_register g_trampoline(g_module_table[0][4]) File "gsi/gsi-python", line 549, in g_trampoline pc = pc() File "gsi/gsi-python", line 832658, in g_bb79__23__23_default_2d_path_2d_expand return g_bb80__23__23_default_2d_path_2d_expand() File "gsi/gsi-python", line 832628, in g_bb80__23__23_default_2d_path_2d_expand return g_stack[g_sp+1]() File "gsi/gsi-python", line 825016, in g_bb3__23__23_file_2d_info_2d_aux return g_bb6__23__23_file_2d_info_2d_aux() File "gsi/gsi-python", line 825041, in g_bb6__23__23_file_2d_info_2d_aux return g_bb1__23__23_os_2d_file_2d_info() File "gsi/gsi-python", line 49501, in g_bb1__23__23_os_2d_file_2d_info g_r1 = g_file_info(g_r1, g_scm2host(g_r2), g_scm2host(g_r3)) File "gsi/gsi-python", line 9445, in g_file_info fi.slots[ 3] = g_host2scm(st.st_ino) File "gsi/gsi-python", line 443, in g_host2scm raise Exception("host2scm error") Exception: host2scm error python -V Python 2.7.16 python3 -V Python 3.7.7 sw_vers ProductName: Mac OS X ProductVersion: 10.15.4

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Troubleshooting build problem with shallow git clone
by Lassi Kortela 06 Avr '20

06 Avr '20

Can anyone else replicate the build failure using a shallow clone? When I do: git clone https://github.com/gambit/gambit.git --depth 1 cd gambit ./configure --prefix=$HOME/tmp/gambit-shallow-clone make The build fails in about a minute with errors like the ones below. These are from clang; configuring with CC=gcc-9 to ensure GNU GCC is being used, gives the same errors with slightly different messages. I wonder what the key difference between full and shallow clones is. Could it be about git tags being absent from the shallow clone? _kernel.c:23183:52: error: too few arguments to function call, expected 2, have 1 ___CFUN_ASSIGN(___result,___os_network_info(___arg1)) ~~~~~~~~~~~~~~~~~~ ^ ../include/gambit.h:7894:34: note: expanded from macro '___CFUN_ASSIGN' #define ___CFUN_ASSIGN(r,val)r = val; ^~~ ./os_setup.h:221:1: note: '___os_network_info' declared here extern ___SCMOBJ ___os_network_info ^ _kernel.c:23660:59: error: too few arguments to function call, expected 3, have 2 ___CFUN_ASSIGN(___result,___os_rename_file(___arg1,___arg2)) ~~~~~~~~~~~~~~~~~ ^ ../include/gambit.h:7894:34: note: expanded from macro '___CFUN_ASSIGN' #define ___CFUN_ASSIGN(r,val)r = val; ^~~ ./os_files.h:321:1: note: '___os_rename_file' declared here extern ___SCMOBJ ___os_rename_file ^ 11 errors generated.

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Universal backend progress
by Marc Feeley 02 Avr '20

02 Avr '20

The universal backend has reached a new milestone. There is now a --enable-targets=… configure option to enable individual target languages in addition to C. Currently JavaScript and Python are supported. The universal backend is sufficiently feature-full to compile the gsi interpreter and builtin modules and support the module system and dynamically loading compiled modules: % ./configure --enable-targets=js,python --enable-single-host % make % make modules % gsc/gsc -:= -target js -exe -o gsi/gsi-js -prelude '(include"~~lib/header.scm")' gsi/_gsi.scm % gsc/gsc -:= -target python -exe -o gsi/gsi-python -prelude '(include"~~lib/header.scm")' gsi/_gsi.scm % gsi/gsi lib/ _test/test *** all tests passed out of a total of 40 tests % gsi/gsi-js lib/ _test/test *** all tests passed out of a total of 40 tests % gsi/gsi-python lib/ _test/test *** all tests passed out of a total of 40 tests % gsc/gsc -:= -target js fib.scm % gsi/gsi-js fib.o1 (time (fib 30)) 0.078000 secs real time 0.078000 secs cpu time (0.078000 user, 0.000000 system) no collections no bytes allocated no minor faults no major faults 832040 % gsi/gsi-js fib.scm (time (fib 30)) 1.877000 secs real time 1.877000 secs cpu time (1.877000 user, 0.000000 system) no collections no bytes allocated no minor faults no major faults 832040 % gsi/gsi fib.scm (time (fib 30)) 0.243592 secs real time 0.243565 secs cpu time (0.241976 user, 0.001589 system) 20 collections accounting for 0.001477 secs real time (0.001463 user, 0.000023 system) 172322368 bytes allocated 2028 minor faults no major faults 832040 So the JavaScript backend generates code that is about 8x slower than the code generated by the C backend. Marc

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[CfP] 2020 Scheme and Functional Programming Workshop
by Jason Hemann 30 Mar '20

30 Mar '20

Hello, Thank you for your attention, and my apologies for any duplication you receive. Please find below the Call for Papers for the *2020 Scheme and Functional Programming Workshop*. We look forward to your submissions. *Call for Papers*The 2020 Scheme and Functional Programming Workshop is calling for submissions. We invite high-quality papers about novel research results, lessons learned from practical experience in industrial or educational setting, and even new insights on old ideas. We welcome and encourage submissions that apply to any language that can be considered Scheme: from strict subsets of RnRS to other “Scheme” implementations, to Racket, to Lisp dialects including Clojure, Emacs Lisp, Common Lisp, to functional languages with continuations and/or macros (or extended to have them) such as Dylan, ECMAScript, Hop, Lua, Scala, Rust, etc. The elegance of the paper and the relevance of its topic to the interests of Schemers will matter more than the surface syntax of the examples used. Topics of interest include (but are not limited to): Interaction: program-development environments, debugging, testing, refactoring Implementation: interpreters, compilers, tools, garbage collectors, benchmarks Extension: macros, hygiene, domain-specific languages, reflection, and how such extension affects interaction. Expression: control, modularity, ad hoc and parametric polymorphism, types, aspects, ownership models, concurrency, distribution, parallelism, non-determinism, probabilism, and other programming paradigms Integration: build tools, deployment, interoperation with other languages and systems Formal semantics: Theory, analyses and transformations, partial evaluation Human Factors: Past, present and future history, evolution and sociology of the language Scheme, its standard and its dialects Education: approaches, experiences, curricula Applications: industrial uses of Scheme Scheme pearls: elegant, instructive uses of Scheme *Important dates* Submission deadline is 15 May 2020. Authors will be notified by 12 June 2020. Camera-ready versions are due 30 June 2020. All deadlines are (23:59 UTC-12), “Anywhere on Earth”. Submission Information Paper submissions must use the format acmart and its sub-format acmlarge. They must be in PDF, printable in black and white on US Letter size. Microsoft Word and LaTeX templates for this format are available at: http://www.sigplan.org/Resources/Author/ <https://jason-hemann-dot-yamm-track.appspot.com/Redirect?ukey=1hySDOusaj9Sw…> This format is in line with ACM conferences (such as ICFP with which we are colocated). It is recommended to use the review option when submitting a paper; this option enables line numbers for easy reference in reviews. We want to encourage all kinds of submissions, including full papers, experience reports and lightning talks. Papers and experience reports are limited to 14 pages, but we encourage submitting smaller papers. Lightning talks are limited to 192 words. Each accepted paper and report will be presented by its authors in a 25 minute slot including Q&A. Each accepted lightning talk will be presented by its authors in a 5 minute slot, followed by 5 minutes of Q&A. The size limits above exclude references and any optional appendices. There are no size limits on appendices, but the papers should stand without the need to read them, and reviewers are not required to read them. Authors are encouraged to publish any code associated to their papers under an open source license, so that reviewers may try the code and verify the claims. Proceedings will be printed as a Technical Report at the University of Michigan and uploaded to arXiv.org <https://jason-hemann-dot-yamm-track.appspot.com/Redirect?ukey=1hySDOusaj9Sw…> . Publication of a paper at this workshop is not intended to replace conference or journal publication, and does not preclude re-publication of a more complete or finished version of the paper at some later conference or in a journal. Sincerely, Jason Hemann, Northeastern University *Organizing Committee* Michael D. Adams (Program Co-Chair), University of Michigan Baptiste Saleil (Program Co-Chair), IBM Canada Jason Hemann (Publicity Chair), Northeastern University *Program Committee*Michael D. Adams (Program Co-Chair), University of Michigan Baptiste Saleil (Program Co-Chair), IBM Canada Maxime Chevalier-Boisvert, Université de Montréal Ryan Culpepper, Czech Technical University Kimball Germane, University of Utah Yukiyoshi Kameyama, University of Tsukuba Andy Keep, Cisco Systems, Inc Julien Pagès, Université de Montréal Alexey Radul *Steering Committee*Will Byrd, University of Alabama at Birmingham Will Clinger, The Larceny Project Marc Feeley, Université de Montréal Dan Friedman, Indiana University Olin Shivers, Northeastern University [image: beacon]

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How to distinguish procedures from procedures?
by Jörg F. Wittenberger 27 Mar '20

27 Mar '20

Hi, A few questions regarding procedures: There are several classes of objects passing the `procedure?` predicate. - Is there a full list? - How expensive are those at startup initialization and call time? (A rough ordering would do. Just to avoid expensive ones when there's the option.) - I tend to use the following receipe to control the global exports with gambit (currently nailed in practice to 0.9.2 for use with lambdanative). Does imply any runtime overhead vs. no use of `let` and resorting to gambits namespace facility? (define my-exported-proc #f) (let (...) (define (my-private-proc ...) ...) (define (my-to-be-exported ...) ...) (set! my-exported-proc my-to-be-exported)) - The real question of mine: How could I create additional runtime predicates for procedures with minimal overhead? Any way to attach tags to procedures? (Let's rule out the trivial solution to collect procedures which should pass the predicate in a data structure and look it up.) I need something where this fiction make sense (upper case be "dunno how"): ;; ATTACH-TAG! is compiletime, maybe even only compiletime. (define-macro (bless! proc tag) `(ATTACH-TAG! ,proc ',tag)) (define (make-blessed tag) (lambda (obj) (and (procedure? obj) (eq? (GET-TAG obj) tag)))) (define ispure? (make-blessed 'pure)) (bless! + 'pure) ;;; at runtime: (ispure? +) ; => #t (ispure? -) ; => #f ;; yeah, we forgot to bless is :-/ Thanks so much Jörg

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Gambit universal library in the browser
by Marc Feeley 25 Mar '20

25 Mar '20

With the latest commit the Gambit universal library can be used in the browser… it is as simple as: % make _gambit.js % gsc/gsc -:= -target js -exe -o webapp.js webapp.scm % open webapp.html webapp.scm: (declare (extended-bindings)) (define (document.write html) (##inline-host-statement "document.write(g_scm2host(@1@));" html)) (document.write "<h1>Hello world!</h1>") webapp.html: <!doctype html> <html> <head> <meta charset="utf-8"> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>webapp</title> </head> <body> <script type="text/javascript" src="webapp.js"></script> </body> </html>

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Universal library improvements
by Marc Feeley 24 Mar '20

24 Mar '20

With the most recent changes to the universal backend and library, Gambit's JavaScript and Python backends are now much easier to use. The following steps will build and install the universal library with the JavaScript and Python backends: % make % make _gambit.js _gambit.py % make install Scheme programs can be compiled to either JavaScript or Python shell scripts by specifying the -exe flag and the target language to gsc: % gsc -target js -o fib-js -exe fib.scm % ./fib-js (time (f 30)) 0.076000 secs real time 0.076000 secs cpu time (0.076000 user, 0.000000 system) no collections no bytes allocated no minor faults no major faults 832040 % cat fib.scm (declare (standard-bindings)) (define (f n) (if (< n 2) n (+ (f (- n 1)) (f (- n 2))))) (println (time (f 30))) It is also possible to build a version of the Gambit interpreter implemented in JavaScript with: % gsc -target js -o gsi-js -exe -prelude '(include"../lib/header.scm")' gsi/_gsi.scm Replacing "js" with "python" will build gsi implemented in Python: % ./gsi-python Gambit v4.9.3 > (host-decl "import os") > (define (env var) (host-eval "g_host2scm(os.environ[g_scm2host(@1@)])" var)) > (env "TERM") "dumb" > ,q % ./gsi-js Gambit v4.9.3 > (define (f n) (if (< n 2) n (+ (f (- n 1)) (f (- n 2))))) > (time (f 30)) (time (f 30)) 2.254000 secs real time 2.254000 secs cpu time (2.254000 user, 0.000000 system) no collections no bytes allocated no minor faults no major faults 832040 > (apropos 'inexact) "##" namespace: exact->inexact, fail-check-inexact-real, fail-check-inexact-real-list, flonum->inexact-exponential-format, inexact, inexact->exact, inexact? empty namespace: exact->inexact, inexact, inexact->exact, inexact? > (define (show x) (host-exec "console.log(g_scm2host(@1@));" x)) > (show "hello") hello > (show (host-eval "g_host2scm(new Date().toString())")) Sun Mar 22 2020 23:20:29 GMT-0400 (GMT-04:00) > ,q The universal library is quite large (> 30MB)... so the memory conscious may choose to link with a custom runtime library that defines only the procedures needed. The compiler's -l flag is useful to specify the library to link with. ;;; minlib.scm (println "running minlib.scm") (define (twice thunk) ;; exported procedure (thunk) (thunk)) (define (##run-each-module) (declare (extended-bindings) (not safe)) (let ((mods (##vector-ref ##program-descr 0))) (let loop ((i 1)) ;; start at module after the current one (if (##fx< i (##vector-length mods)) (let ((mod (##vector-ref mods i))) ((##vector-ref mod 4)) ;; call module's init procedure (loop (##fx+ i 1))))))) (##run-each-module) ;; run each module (after the current one) ;; To use this minimal library to compile a program prog.scm, ;; follow these steps: ;; ;; % cat prog.scm ;; (twice (lambda () (println "hello"))) ;; % TARGET=js # could also be python or php ;; % gsc -target $TARGET -c minlib.scm ;; % gsc -target $TARGET -l minlib -exe prog.scm ;; % ./prog ;; running minlib.scm ;; hello ;; hello ;; % head -1 prog ;; #! /usr/bin/env node There are still some issues with the universal backend, but it is now much closer to the features offered by the C backend. Marc

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Parameter objects performance Q
by Adam 21 Mar '20

21 Mar '20

Hi Marc, I can't recall if this is somewhere in the mailing list archive from before: I recall that you indicated that parameter objects are expensive. Would you mind describing/quantifying the average/worst case/best case cost for assigning a value to a parameter object by parameterization (|parameterize|), and for accessing a parameter object (load or store operation by invoking it as a closure)? Parameter objects are very practical and have ample use scenarios, both high-level and relatively low-level. Thanks, Adam

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