Poly/ML November 2016

polyml@lists.polyml.org

3 participants
3 discussions

linking polyML modules to C
by dtopham＠gmail.com 09 Nov '18

09 Nov '18

After more experimenting with GUI in SML, I would like to now try calling an SML module from a C program. That way, the GUI could be built using traditional imperative techniques and the program logic could be written in SML. I see how to call a C function from SML, but and not so clear on how to call an SML function from a C program. I want to build code using polyc and then link with a C main program, but could anyone show me a simple example of calling that function and getting its return value? for example, I have defined: fun sum i n f = if i > n then 0.0 else f i + sum (i+1) n f ; fun int2real x = real x ; in linkToC.sml and #include <iostream> #include <fstream> std::ofstream ofs; int main() { std::cout << sum(1,10,int2real) << std::endl; ofs.open("table.dat"); for(int i = 0; i < 20; i++) ofs << i << '\t' << sum(1,i,int2real) << std::endl; } in linkToC.cpp Looking in the polyc script, I thought adding the -c option might allow me to build the object code which I could then link to the sml functions, but it complains about not having a main. Could someone point me in the right direction? Thanks, Dave On Mon, Dec 15, 2014 at 11:44 AM, David Topham <dtopham at gmail.com> wrote: > David, Thank you so much! I really appreciate your help with this. Your > sample below builds fine with polyc on my system (PolyML 5.5.2). I am using > a minimal Linux distribution named TinyCore ( > http://distro.ibiblio.org/tinycorelinux/) which comes with OpenMotif > 2.3.3 It runs in a virtual machine within another computer only taking up > a few hundred MBs! > > I am going to use it to help my students explore Discrete Math next > semester (this textbook uses SML for that purpose: > http://cs.wheaton.edu/~tvandrun/dmfp/). > > I also found a reasonably current project using PolyML and Motif here: > http://www.lemma-one.com/ProofPower/index/ > > ...however it was built on PolyML 4 and has not yet been ported to the > newer version (e.g. depends on PolyML.commit which no longer seems to be > supported). > > Happy Holidays to everyone in the PolyML community! > > -David Topham > > >> Re: GUI Interface (David Matthews) >> >> I've experimented with building a stand-alone executable with Motif and >> succeeded in getting it to work for me using polyc. (It required >> building Poly/ML with --with-x). I took the example from >> http://www.polyml.org/docs/Motif.html and wrapped it up in a function. >> I did find a problem, though. It looks as though the function has to >> suspend itself with something like Posix.Process.pause otherwise nothing >> happens. I seem to recall that the Motif stuff is handled on a separate >> thread to allow the REPL to continue to accept commands. With a >> stand-alone application there isn't a REPL so without the "pause" it >> terminates immediately. >> >> David >> >> open XWindows ; >> open Motif ; >> >> fun main() = >> let >> val shell = >> XtAppInitialise "" "xed" "Editor" [] [XmNwidth 400, XmNheight 400] ; >> >> val main = XmCreateMainWindow shell "main" [] ; >> >> val bar = XmCreateMenuBar main "bar" [] ; >> >> val fileMenu = XmCreateCascadeButton bar "file" [XmNlabelString "File"] ; >> val editMenu = XmCreateCascadeButton bar "edit" [XmNlabelString "Edit"] ; >> val viewMenu = XmCreateCascadeButton bar "view" [XmNlabelString "View"] ; >> val helpMenu = XmCreateCascadeButton bar "help" [XmNlabelString "Help"] ; >> >> val command = XmCreateText main "command" [XmNeditMode >> XmSINGLE_LINE_EDIT] ; >> >> val hscroll = XmCreateScrollBar main "hscroll" [XmNorientation >> XmHORIZONTAL] ; >> val vscroll = XmCreateScrollBar main "vscroll" [XmNorientation >> XmVERTICAL] ; >> >> val work = XmCreateDrawingArea main "work" [] ; >> in >> >> XtManageChildren [fileMenu, editMenu, viewMenu, helpMenu] ; >> XtManageChildren [bar, command, hscroll, vscroll, work] ; >> >> XmMainWindowSetAreas main bar command hscroll vscroll work ; >> >> XtManageChild main ; >> XtRealizeWidget shell; >> Posix.Process.pause() >> end; >> >> >> ------------------------------ >> >> _______________________________________________ >> polyml mailing list >> polyml at inf.ed.ac.uk >> http://lists.inf.ed.ac.uk/mailman/listinfo/polyml >> >> End of polyml Digest, Vol 110, Issue 12 >> *************************************** >> >> -- >> The University of Edinburgh is a charitable body, registered in >> Scotland, with registration number SC005336. >> >>

2 3

Get errno
by kostirya＠gmail.com 07 Dec '16

07 Dec '16

Hello. Could you please advise a good way to obtain the errno value. I use the following way but I don't like it: > cat errno.c #include <errno.h> int get_errno (void) { return errno; } > cat errno.sml open Foreign val errnolib = loadLibrary "errno.so" val get_errno = buildCall0 ((getSymbol errnolib "get_errno"), (), cInt) fun main () = print ("errno=" ^ (Int.toString (get_errno())) ^ "\n") > cc -shared -o errno.so errno.c > polyc -o errno errno.sml > env LD_LIBRARY_PATH=. ./errno errno=0

3 5

Thank you very much
by kostirya＠gmail.com 18 Nov '16

18 Nov '16

Hello. Thank you very much to everyone who helped me. I finally completed the Standard ML version of my server (with event-driven architecture). I made sure in practice that high-performance asynchronous servers can be done using PolyML and MLton. The performance of PolyML also surprised me pleasantly... For MLton I used memmove for string concatination. I also found out that PolyML FFI is a bit slow. In general, my impression is very positive. Thank you for PolyML and MLton. Nick.

1 0

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

Poly/ML November 2016