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Is porting to word-oriented machines important?
by Bradley Lucier 30 Mar '05

30 Mar '05

There is some code in include/gambit.h that attempts to allow Gambit-C 4.0beta to run on machines like the older Crays that have only word (64-bit) access and not byte (8-bit) access to memory. I'm not sure that this code works, and it's getting in the way of some low-level optimizations I'd like to make to the various [u,s,f][8,16,32,64]vector primitives in gambit.h. So my question---is it of interest to anyone to run Gambit-C on machines that have only word access to memory? Brad

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RE: [gambit-list] Problem using 'if' in a macro to conditionalydefinea let form
by Logan, Patrick D 30 Mar '05

30 Mar '05

In fact you don't need UNQUOTE-SPLICING and a nested BACKQUOTE if you generate the entire binding section. Works as good, but even funner. `(let ,(if ...) ...) -Patrick -----Original Message----- From: Eric Merritt [mailto:cyberlync@gmail.com] Sent: Tue 3/29/2005 6:14 PM To: Logan, Patrick D Subject: Re: [gambit-list] Problem using 'if' in a macro to conditionalydefinea let form Cool, thats a simple solution I should have thought of. On Tue, 29 Mar 2005 18:04:05 -0800, Logan, Patrick D <patrick.d.logan(a)intel.com> wrote: > Ah, OK. Because the UNQUOTE within the LET bindings has to return > something, and there is no "else" clause in the IF, you get by default a > #!VOID. > > Instead rewrite the IF to generate both bindings in the LET. Instead of > UNQUOTE, use UNQUOTE-SPLICING... > > `(let (,@(if (is-cool? somestuff) > `((x ,somestuff) > (z do-something-else-cool)) > `((x ,somestuff)))) > ...) > > That should be close, plus or minus a typo or two. > > -Patrick > > -----Original Message----- > From: gambit-list-bounces(a)iro.umontreal.ca > [mailto:gambit-list-bounces@iro.umontreal.ca] On Behalf Of Eric Merritt > Sent: Tuesday, March 29, 2005 5:50 PM > To: gambit-list(a)iro.umontreal.ca > Subject: Re: [gambit-list] Problem using 'if' in a macro to > conditionalydefinea let form > > see inline -> > > On Tue, 29 Mar 2005 17:16:29 -0800, Logan, Patrick D > <patrick.d.logan(a)intel.com> wrote: > > Not sure what you really want to have expanded and what you want in > the > > result. I have found it helpful to begin with the end in mind. > > (define-macro (foo somestuff) > `(let ((x ,sumstuff) > ,(if (is-cool sumstuff) > `(z (do-something-else-cool)))) > (some-more-stuff)) > > So this would preferably expand in two ways depending on what 'sumstuff' > is > > (let ((x avalue) > (z (do-something-else-cool))) > (some-more-stuff)) > > or > > (let ((x avalue)) > (some-more-stuff)) > > However, the second option is impossible because the above macro will > expand to > > (let ((x avalue) > #!void) > (some-more-stuff))) > > in the face of an uncool 'sumstuff'. At least thats what it looks like > is happening when I expand the macro. > > > Assuming you want the initial form to look like... > > > > (FOO SOMESTUFF) > > > > Can you provide an example, i.e. replace SOMESTUFF with some actual > > stuff. > > Ok simple enough. So lets say sumstuff is > > '((cool 33) (not-cool 44)) > > and is-cool is defined as > > (define (is-cool lst) > (cond > ((null? lst) #f) > ((equal? 'cool (caar lst)) #t) > (else (is-cool (cdr lst))))) > > > > > Then for this example, what do you want the final form to look like > > after expansion? > > (let ((x avalue) > (z (do-something-else-cool))) > (some-more-stuff)) > > or > > (let ((x avalue)) > (some-more-stuff)) > > depending on the value of sumstuff > > > Now defining the macro is a simple matter of programming. Outside of > the > > define-macro, you can play with quasiquotes to get just the data > looking > > the way you want it. > > Unfortunately, unless I am missing something big I can't for reasons > stated above. Because although this > > (let ((x avalue) > (z (do-something-else-cool))) > (some-more-stuff)) > > can be evaluated to just fine. I cannot get this > > (let ((x avalue)) > (some-more-stuff)) > > to result. In instances where sumstuff is (is-cool sumstuff) evaluates > to false I get an ill-formed let error. > _______________________________________________ > Gambit-list mailing list > Gambit-list(a)iro.umontreal.ca > http://mailman.iro.umontreal.ca/mailman/listinfo/gambit-list > -- I'm a programmer, I don't have to spell correctly; I just have to spell consistently

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RE: [gambit-list] Problem using 'if' in a macro to conditionalydefinea let form
by Logan, Patrick D 30 Mar '05

30 Mar '05

Ah, OK. Because the UNQUOTE within the LET bindings has to return something, and there is no "else" clause in the IF, you get by default a #!VOID. Instead rewrite the IF to generate both bindings in the LET. Instead of UNQUOTE, use UNQUOTE-SPLICING... `(let (,@(if (is-cool? somestuff) `((x ,somestuff) (z do-something-else-cool)) `((x ,somestuff)))) ...) That should be close, plus or minus a typo or two. -Patrick -----Original Message----- From: gambit-list-bounces(a)iro.umontreal.ca [mailto:gambit-list-bounces@iro.umontreal.ca] On Behalf Of Eric Merritt Sent: Tuesday, March 29, 2005 5:50 PM To: gambit-list(a)iro.umontreal.ca Subject: Re: [gambit-list] Problem using 'if' in a macro to conditionalydefinea let form see inline -> On Tue, 29 Mar 2005 17:16:29 -0800, Logan, Patrick D <patrick.d.logan(a)intel.com> wrote: > Not sure what you really want to have expanded and what you want in the > result. I have found it helpful to begin with the end in mind. (define-macro (foo somestuff) `(let ((x ,sumstuff) ,(if (is-cool sumstuff) `(z (do-something-else-cool)))) (some-more-stuff)) So this would preferably expand in two ways depending on what 'sumstuff' is (let ((x avalue) (z (do-something-else-cool))) (some-more-stuff)) or (let ((x avalue)) (some-more-stuff)) However, the second option is impossible because the above macro will expand to (let ((x avalue) #!void) (some-more-stuff))) in the face of an uncool 'sumstuff'. At least thats what it looks like is happening when I expand the macro. > Assuming you want the initial form to look like... > > (FOO SOMESTUFF) > > Can you provide an example, i.e. replace SOMESTUFF with some actual > stuff. Ok simple enough. So lets say sumstuff is '((cool 33) (not-cool 44)) and is-cool is defined as (define (is-cool lst) (cond ((null? lst) #f) ((equal? 'cool (caar lst)) #t) (else (is-cool (cdr lst))))) > > Then for this example, what do you want the final form to look like > after expansion? (let ((x avalue) (z (do-something-else-cool))) (some-more-stuff)) or (let ((x avalue)) (some-more-stuff)) depending on the value of sumstuff > Now defining the macro is a simple matter of programming. Outside of the > define-macro, you can play with quasiquotes to get just the data looking > the way you want it. Unfortunately, unless I am missing something big I can't for reasons stated above. Because although this (let ((x avalue) (z (do-something-else-cool))) (some-more-stuff)) can be evaluated to just fine. I cannot get this (let ((x avalue)) (some-more-stuff)) to result. In instances where sumstuff is (is-cool sumstuff) evaluates to false I get an ill-formed let error. _______________________________________________ Gambit-list mailing list Gambit-list(a)iro.umontreal.ca http://mailman.iro.umontreal.ca/mailman/listinfo/gambit-list

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RE: [gambit-list] Problem using 'if' in a macro to conditionaly definea let form
by Logan, Patrick D 30 Mar '05

30 Mar '05

Not sure what you really want to have expanded and what you want in the result. I have found it helpful to begin with the end in mind. Assuming you want the initial form to look like... (FOO SOMESTUFF) Can you provide an example, i.e. replace SOMESTUFF with some actual stuff. Then for this example, what do you want the final form to look like after expansion? Now defining the macro is a simple matter of programming. Outside of the define-macro, you can play with quasiquotes to get just the data looking the way you want it. -Patrick -----Original Message----- From: gambit-list-bounces(a)iro.umontreal.ca [mailto:gambit-list-bounces@iro.umontreal.ca] On Behalf Of Eric Merritt Sent: Tuesday, March 29, 2005 5:06 PM To: Gambit List Subject: [gambit-list] Problem using 'if' in a macro to conditionaly definea let form Guys, I am having a bit of a problem with if in a macro and I could use some help. Say I have a macro similar to the following (define-macro (foo somestuff) `(let ((x ,sumstuff) ,(if (is-cool sumstuff) `(do-something-else-cool))) (some-more-stuff))) this will result in an ill formed let anytime 'some-stuff' isn't cool. Thats becuase the 'if' statement returns #!void in the expansion which is invalid. Cond does the same thing. Is there an alternate way to do this, am I missing something obvious? I get the feeling that I am. Thanks, Eric _______________________________________________ Gambit-list mailing list Gambit-list(a)iro.umontreal.ca http://mailman.iro.umontreal.ca/mailman/listinfo/gambit-list

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Problem using 'if' in a macro to conditionaly define a let form
by Eric Merritt 30 Mar '05

30 Mar '05

Guys, I am having a bit of a problem with if in a macro and I could use some help. Say I have a macro similar to the following (define-macro (foo somestuff) `(let ((x ,sumstuff) ,(if (is-cool sumstuff) `(do-something-else-cool))) (some-more-stuff))) this will result in an ill formed let anytime 'some-stuff' isn't cool. Thats becuase the 'if' statement returns #!void in the expansion which is invalid. Cond does the same thing. Is there an alternate way to do this, am I missing something obvious? I get the feeling that I am. Thanks, Eric

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srfi-13 define-macro replacements
by ben＠crickhollow.fuhok.net 28 Mar '05

28 Mar '05

Here are define-macro versions of `let-string-start+end' and `let-string-start+end2' needed by the reference implementation of srfi-13. I'm still reading over everyone else's work, so I don't know if these will be useful or not. ------------------------------------------------------------------------------- (define-macro (let-string-start+end start+end proc s-exp args-exp . body) (or (list? start+end) (error "let-string-start+end: start+end must be list")) (case (length start+end) ((2) `(receive ,start+end (string-parse-final-start+end ,proc ,s-exp ,args-exp) ,@body)) ((3) `(receive ,start+end (string-parse-start+end ,proc ,s-exp ,args-exp) ,@body)) (else (error "let-string-start+end: wrong length start+end")))) (define-macro (let-string-start+end2 start+end-pair proc str1 str2 args . body) (or (list? start+end-pair) (error "let-string-start+end: start+end-pair must be list")) (let ((rest (gensym)) (procv (gensym))) (receive (start1 end1 start2 end2) (apply values start+end-pair) `(let ((,procv ,proc)) ; Make sure PROC is only evaluated once. (let-string-start+end (,rest ,start1 ,end1) ,procv ,str1 ,args (let-string-start+end (,start2 ,end2) ,procv ,str2 ,rest ,@body)))))) ------------------------------------------------------------------------------- Regards, Ben

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Whither ##unchecked-structure-ref?
by Bradley Lucier 27 Mar '05

27 Mar '05

Marc: I tried the following---the problem arises when I try to look at the macro expansion of this compiled file: [descartes:programs/SAGE14/libraries] lucier% gsc loading /usr/local/Gambit-C/gambcext.scm Gambit Version 4.0 beta 12 > (with-output-to-file "crap.scm" (lambda () (compile-file "srfis.scm" '(expansion)))) *** ERROR -- Unbound variable: ##unchecked-structure-ref 1> > (compile-file "srfis.scm") gcc: unrecognized option '-no-cpp-precomp' #t I also find: banach-26% grep -r unchecked-structure-ref * gsc/_prims.scm:("##unchecked-structure-ref" (4) #f () 0 (#f) extended) gsc/_t-c-2.scm:(targ-op "##unchecked-structure-ref" gsc/_t-c-2.scm:(targ-spec "##structure-ref" (targ-u "##unchecked-structure-ref")) lib/_io.scm: (##unchecked-structure-ref lib/_kernel.scm: (##unchecked-structure-ref type 1 ##type-type ##type-id)) lib/_kernel.scm: (##unchecked-structure-ref type 2 ##type-type ##type-name)) lib/_kernel.scm: (##unchecked-structure-ref type 3 ##type-type ##type-flags)) lib/_kernel.scm: (##unchecked-structure-ref type 4 ##type-type ##type-super)) lib/_kernel.scm: (##unchecked-structure-ref type 5 ##type-type ##type-fields)) lib/_kernel.scm: (##unchecked-structure-ref type 6 ##type-type ##type-cfields)) lib/_kernel.scm: (##unchecked-structure-ref obj i type proc) Brad

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SRFI-1
by Eric Merritt 26 Mar '05

26 Mar '05

I have ported SRFI-1 to gambit and put it in its own "srfi1#" namespace. It was pretty trivial to do. I think this might be of interest to other people so I figured I would offer it the community. For those interested, I have also ported Yasos to gambit. The main thing I did was convert the hygienic macros to un-hygienic macros so that it wouldn't depend on syntax-case.scm and error line numbers would be a little more accurate. In the future I intend to extend it with method-missing and perform functionality. Neither of these are extremely well tested at this point. I am in the process of finding and porting a unit test framework but I have not finished yet. Once I do I will add unit tests for the above two to the package. It may be that someone else has already made these available for gambit, if so just ignore this and I apologize for the noise.

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Does , l do anything different than , s in the debugger?
by Bradley Lucier 25 Mar '05

25 Mar '05

I think Maxin Naumov found another bug. Man, these students that take the documentation seriously ;-)! I tried a straightforward definition of (fact n) and tried to leap through the subcall (fact (- n 1)) and it didn't work; in fact, ,l seemed to do the same thing as ,s in all cases. Looks like a bug. Brad

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RE: [gambit-list] Calling from C on Windows
by Dan Hristodorescu 21 Mar '05

21 Mar '05

Hi Marc, It works fine now. Thank you very much. Regards, Dan. -----Original Message----- From: Marc Feeley [mailto:feeley@IRO.UMontreal.CA] Sent: Saturday, March 19, 2005 9:05 AM To: dhristodorescu(a)borderfree.com Cc: gambit-list(a)IRO.UMontreal.CA Subject: Re: [gambit-list] Calling from C on Windows I fixed the bug. You need to change the USE_WIN32 section in ___os_device_stream_open_predefined to this: switch (___INT(index)) { case -4: open_console: { ___device_tty *d; if ((e = ___device_tty_setup_console (&d, io_mod.dgroup, direction)) != ___FIX(___NO_ERR)) return e; dev = ___CAST(___device_stream*,d); break; } default: { switch (___INT(index)) { default: case -1: h = GetStdHandle (STD_INPUT_HANDLE); break; case -2: h = GetStdHandle (STD_OUTPUT_HANDLE); break; case -3: h = GetStdHandle (STD_ERROR_HANDLE); break; } if (h == INVALID_HANDLE_VALUE) return err_code_from_GetLastError (); if (GetFileType (h) == FILE_TYPE_UNKNOWN) goto open_console; ... The bug occurs on Windows when the Gambit runtime is being run as a windowed application (no problem in console applications). In a windowed application the GetStdHandle calls (which are meant to return the standard input/output/error) return a handle whose type is not recognized by Gambit (it is not a file, a pipe, a socket, a console, or a serial port). This caused the runtime to terminate. The fix adds a check for the handle type and associates a console window to stdin/out/err if their type is unknown. So for windowed applications any "standard I/O" from Scheme will go to a freshly created console (unless stdin/out/err were redirected). Marc

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