Metasepi team meeting #17: Invariant captured by ATS's API

Metasepi team meeting #17:　Invariant captured by ATS's API




Metasepi team meeting #17:Invariant captured by ATS's API

Kiwamu Okabe @ Metasepi ProjectKiwamu Okabe @ Metasepi ProjectKiwamu Okabe @ Metasepi ProjectKiwamu Okabe @ Metasepi ProjectKiwamu Okabe @ Metasepi Project

Who am I?Who am I?Who am I?Who am I?Who am I?

☆ http://www.masterq.net/☆ http://www.masterq.net/☆ http://www.masterq.net/☆ http://www.masterq.net/☆ http://www.masterq.net/

☆ Self employed software engineer☆ Self employed software engineer☆ Self employed software engineer☆ Self employed software engineer☆ Self employed software engineer

☆ Trade name := METASEPI DESIGN☆ Trade name := METASEPI DESIGN☆ Trade name := METASEPI DESIGN☆ Trade name := METASEPI DESIGN☆ Trade name := METASEPI DESIGN

☆ Founder of Metasepi Project☆ Founder of Metasepi Project☆ Founder of Metasepi Project☆ Founder of Metasepi Project☆ Founder of Metasepi Project

☆ A Debian Maintainer☆ A Debian Maintainer☆ A Debian Maintainer☆ A Debian Maintainer☆ A Debian Maintainer

☆ 10 years' experience in developing OS using NetBSD☆ 10 years' experience in developing OS using NetBSD☆ 10 years' experience in developing OS using NetBSD☆ 10 years' experience in developing OS using NetBSD☆ 10 years' experience in developing OS using NetBSD

Remember Heartbleed bug?Remember Heartbleed bug?Remember Heartbleed bug?Remember Heartbleed bug?Remember Heartbleed bug?

Should we use safer language than C?Should we use safer language than C?Should we use safer language than C?Should we use safer language than C?Should we use safer language than C?== In English =="Preventing heartbleed bugs with safe programming languages"http://bluishcoder.co.nz/2014/04/11/preventing-heartbleed-bugs-with-safe-languages.html

== In Japanease =="安全なプログラミング言語を使って heartbleed を防ぐには"https://github.com/jats-ug/translate/blob/master/Web/bluishcoder.co.nz/2014/04/11/preventing-heartbleed-bugs-with-safe-languages.md

== In English =="Preventing heartbleed bugs with safe programming languages"http://bluishcoder.co.nz/2014/04/11/preventing-heartbleed-bugs-with-safe-languages.html








"A safer systems programming language could have prevented the bug.""A safer systems programming language could have prevented the bug.""A safer systems programming language could have prevented the bug.""A safer systems programming language could have prevented the bug.""A safer systems programming language could have prevented the bug."

Want the safer language...Want the safer language...Want the safer language...Want the safer language...Want the safer language...

It's the ATS http://www.ats-lang.org/ !It's the ATS http://www.ats-lang.org/ !It's the ATS http://www.ats-lang.org/ !It's the ATS http://www.ats-lang.org/ !It's the ATS http://www.ats-lang.org/ !

☆ Syntax like ML☆ Syntax like ML☆ Syntax like ML☆ Syntax like ML☆ Syntax like ML

☆ Dependent types☆ Dependent types☆ Dependent types☆ Dependent types☆ Dependent types

☆ Linear types☆ Linear types☆ Linear types☆ Linear types☆ Linear types

☆ Without any runtime☆ Without any runtime☆ Without any runtime☆ Without any runtime☆ Without any runtime

☆ Optional GC☆ Optional GC☆ Optional GC☆ Optional GC☆ Optional GC

ATS code can run on 8-bit AVRATS code can run on 8-bit AVRATS code can run on 8-bit AVRATS code can run on 8-bit AVRATS code can run on 8-bit AVRhttps://github.com/fpiot/arduino-mega2560-atshttps://github.com/fpiot/arduino-mega2560-atshttps://github.com/fpiot/arduino-mega2560-atshttps://github.com/fpiot/arduino-mega2560-atshttps://github.com/fpiot/arduino-mega2560-ats

ATS compile flowATS compile flowATS compile flowATS compile flowATS compile flow

Why ATS language is safe?Why ATS language is safe?Why ATS language is safe?Why ATS language is safe?Why ATS language is safe?

☆ Line is at between caller and callee☆ Line is at between caller and callee☆ Line is at between caller and callee☆ Line is at between caller and callee☆ Line is at between caller and callee

☆ ATS applies type to the line☆ ATS applies type to the line☆ ATS applies type to the line☆ ATS applies type to the line☆ ATS applies type to the line

☆ Type can enforce invariant in them☆ Type can enforce invariant in them☆ Type can enforce invariant in them☆ Type can enforce invariant in them☆ Type can enforce invariant in them

{Dependent,Linear} type{Dependent,Linear} type{Dependent,Linear} type{Dependent,Linear} type{Dependent,Linear} type

Dependent typeDependent typeDependent typeDependent typeDependent type

☆ such like Coq or Agda☆ such like Coq or Agda☆ such like Coq or Agda☆ such like Coq or Agda☆ such like Coq or Agda

☆ has universal quantification☆ has universal quantification☆ has universal quantification☆ has universal quantification☆ has universal quantification

☆ has existential quantification☆ has existential quantification☆ has existential quantification☆ has existential quantification☆ has existential quantification

Linear typeLinear typeLinear typeLinear typeLinear type

☆ based on linear logic☆ based on linear logic☆ based on linear logic☆ based on linear logic☆ based on linear logic

☆ manages resource like memory☆ manages resource like memory☆ manages resource like memory☆ manages resource like memory☆ manages resource like memory

Usage of Linear ListUsage of Linear ListUsage of Linear ListUsage of Linear ListUsage of Linear List$ vi sample_list.dats#include "share/atspre_staload.hats"implement main0 () = { val l1 = list_vt_make_pair<int> (1, 2) val l2 = list_vt_make_pair<int> (3, 4) val l3 = list_vt_append (l1, l2) val () = println! ("l3[3] := ", l3[3]) val l4 = list_vt_reverse l3 val () = println! ("l4 := [", l4, "]") val () = free l4}$ patscc -DATS_MEMALLOC_LIBC -o sample_list sample_list.dats$ ./sample_listl3[3] := 4l4 := [4, 3, 2, 1]$ size sample_list text data bss dec hex filename 7908 772 32 8712 2208 sample_list$ ldd sample_list | wc -l3$ nm sample_list| grep "U "| wc -l10

$ vi sample_list.dats#include "share/atspre_staload.hats"implement main0 () = { val l1 = list_vt_make_pair<int> (1, 2) val l2 = list_vt_make_pair<int> (3, 4) val l3 = list_vt_append (l1, l2) val () = println! ("l3[3] := ", l3[3]) val l4 = list_vt_reverse l3 val () = println! ("l4 := [", l4, "]") val () = free l4}$ patscc -DATS_MEMALLOC_LIBC -o sample_list sample_list.dats$ ./sample_listl3[3] := 4l4 := [4, 3, 2, 1]$ size sample_list text data bss dec hex filename 7908 772 32 8712 2208 sample_list$ ldd sample_list | wc -l3$ nm sample_list| grep "U "| wc -l10




Compile error: without freeCompile error: without freeCompile error: without freeCompile error: without freeCompile error: without free$ vi sample_list.dats#include "share/atspre_staload.hats"implement main0 () = { val l1 = list_vt_make_pair<int> (1, 2) val l2 = list_vt_make_pair<int> (3, 4) val l3 = list_vt_append (l1, l2) val () = println! ("l3[3] := ", l3[3]) val l4 = list_vt_reverse l3 val () = println! ("l4 := [", l4, "]")// val () = free l4 // <= Changed}$ patscc -DATS_MEMALLOC_LIBC -o sample_list sample_list.dats--snip--The 2nd translation (binding) of [sample_list.dats] is successfully completed!/home/kiwamu/tmp/sample_list.dats: 59(line=2, offs=22) -- 312(line=10, offs=2): error(3): the linear dynamic variable [l4$3450(-1)] needs to be consumed but it is preserved with the type [S2Eapp(S2Ecst(list_vt0ype_int_vtype); S2Einvar(S2EVar(4104)), S2EVar(4105))] instead.

$ vi sample_list.dats#include "share/atspre_staload.hats"implement main0 () = { val l1 = list_vt_make_pair<int> (1, 2) val l2 = list_vt_make_pair<int> (3, 4) val l3 = list_vt_append (l1, l2) val () = println! ("l3[3] := ", l3[3]) val l4 = list_vt_reverse l3 val () = println! ("l4 := [", l4, "]")// val () = free l4 // <= Changed}$ patscc -DATS_MEMALLOC_LIBC -o sample_list sample_list.dats--snip--The 2nd translation (binding) of [sample_list.dats] is successfully completed!/home/kiwamu/tmp/sample_list.dats: 59(line=2, offs=22) -- 312(line=10, offs=2): error(3): the linear dynamic variable [l4$3450(-1)] needs to be consumed but it is preserved with the type [S2Eapp(S2Ecst(list_vt0ype_int_vtype); S2Einvar(S2EVar(4104)), S2EVar(4105))] instead.




Compile error: use freed nameCompile error: use freed nameCompile error: use freed nameCompile error: use freed nameCompile error: use freed name$ vi sample_list.dats#include "share/atspre_staload.hats"implement main0 () = { val l1 = list_vt_make_pair<int> (1, 2) val l2 = list_vt_make_pair<int> (3, 4) val l3 = list_vt_append (l1, l2) val l4 = list_vt_reverse l3 val () = println! ("l3[3] := ", l3[3]) // <= Changed val () = println! ("l4 := [", l4, "]") val () = free l4}$ patscc -DATS_MEMALLOC_LIBC -o sample_list sample_list.dats--snip--The 2nd translation (binding) of [sample_list.dats] is successfully completed!/home/kiwamu/tmp/sample_list.dats: 242(line=7, offs=35) -- 245(line=7, offs=38): error(3): the linear dynamic variable [l3$3449(-1)] is no longer available.

$ vi sample_list.dats#include "share/atspre_staload.hats"implement main0 () = { val l1 = list_vt_make_pair<int> (1, 2) val l2 = list_vt_make_pair<int> (3, 4) val l3 = list_vt_append (l1, l2) val l4 = list_vt_reverse l3 val () = println! ("l3[3] := ", l3[3]) // <= Changed val () = println! ("l4 := [", l4, "]") val () = free l4}$ patscc -DATS_MEMALLOC_LIBC -o sample_list sample_list.dats--snip--The 2nd translation (binding) of [sample_list.dats] is successfully completed!/home/kiwamu/tmp/sample_list.dats: 242(line=7, offs=35) -- 245(line=7, offs=38): error(3): the linear dynamic variable [l3$3449(-1)] is no longer available.




Compile error: out of rangeCompile error: out of rangeCompile error: out of rangeCompile error: out of rangeCompile error: out of range$ vi sample_list.dats#include "share/atspre_staload.hats"implement main0 () = { val l1 = list_vt_make_pair<int> (1, 2) val l2 = list_vt_make_pair<int> (3, 4) val l3 = list_vt_append (l1, l2) val () = println! ("l3[4] := ", l3[4]) // <= Changed val l4 = list_vt_reverse l3 val () = println! ("l4 := [", l4, "]") val () = free l4}$ patscc -DATS_MEMALLOC_LIBC -o sample_list sample_list.dats--snip--The 2nd translation (binding) of [sample_list.dats] is successfully completed!/home/kiwamu/tmp/sample_list.dats: 215(line=6, offs=38) -- 216(line=6, offs=39): error(3): unsolved constraint: C3NSTRprop(main; S2Eapp(S2Ecst(<); S2EVar(4101->S2Eintinf(4)), S2Eapp(S2Ecst(add_int_int); S2Eintinf(2), S2Eintinf(2))))typechecking has failed: there are some unsolved constraints: please inspect the above reported error message(s) for information.

$ vi sample_list.dats#include "share/atspre_staload.hats"implement main0 () = { val l1 = list_vt_make_pair<int> (1, 2) val l2 = list_vt_make_pair<int> (3, 4) val l3 = list_vt_append (l1, l2) val () = println! ("l3[4] := ", l3[4]) // <= Changed val l4 = list_vt_reverse l3 val () = println! ("l4 := [", l4, "]") val () = free l4}$ patscc -DATS_MEMALLOC_LIBC -o sample_list sample_list.dats--snip--The 2nd translation (binding) of [sample_list.dats] is successfully completed!/home/kiwamu/tmp/sample_list.dats: 215(line=6, offs=38) -- 216(line=6, offs=39): error(3): unsolved constraint: C3NSTRprop(main; S2Eapp(S2Ecst(<); S2EVar(4101->S2Eintinf(4)), S2Eapp(S2Ecst(add_int_int); S2Eintinf(2), S2Eintinf(2))))typechecking has failed: there are some unsolved constraints: please inspect the above reported error message(s) for information.




Typechecked: with assertTypechecked: with assertTypechecked: with assertTypechecked: with assertTypechecked: with assert$ vi sample_list.dats#include "share/atspre_staload.hats"implement main0 () = { val l1 = list_vt_make_pair<int> (1, 2) val l2 = list_vt_make_pair<int> (3, 4) val l3 = list_vt_append (l1, l2) val () = if length l3 > 4 // <= Changed then println! ("l3[4] := ", l3[4]) // <= Changed val l4 = list_vt_reverse l3 val () = println! ("l4 := [", l4, "]") val () = free l4}$ patscc -DATS_MEMALLOC_LIBC -o sample_list sample_list.dats--snip--The 1st translation (fixity) of [sample_list.dats] is successfully completed!The 2nd translation (binding) of [sample_list.dats] is successfully completed!The 3rd translation (type-checking) of [sample_list.dats] is successfully completed!The 4th translation (type/proof-erasing) of [sample_list.dats] is successfully completed!

$ vi sample_list.dats#include "share/atspre_staload.hats"implement main0 () = { val l1 = list_vt_make_pair<int> (1, 2) val l2 = list_vt_make_pair<int> (3, 4) val l3 = list_vt_append (l1, l2) val () = if length l3 > 4 // <= Changed then println! ("l3[4] := ", l3[4]) // <= Changed val l4 = list_vt_reverse l3 val () = println! ("l4 := [", l4, "]") val () = free l4}$ patscc -DATS_MEMALLOC_LIBC -o sample_list sample_list.dats--snip--The 1st translation (fixity) of [sample_list.dats] is successfully completed!The 2nd translation (binding) of [sample_list.dats] is successfully completed!The 3rd translation (type-checking) of [sample_list.dats] is successfully completed!The 4th translation (type/proof-erasing) of [sample_list.dats] is successfully completed!




Type of Linear ListType of Linear ListType of Linear ListType of Linear ListType of Linear List(* File: prelude/basics_dyn.sats *)datavtypelist_vt0ype_int_vtype (a:vt@ype+, int) = | {n:int | n >= 0} list_vt_cons (a, n+1) of (a, list_vt0ype_int_vtype (a, n)) | list_vt_nil (a, 0) of ()stadef list_vt = list_vt0ype_int_vtype

(* File: prelude/basics_dyn.sats *)datavtypelist_vt0ype_int_vtype (a:vt@ype+, int) = | {n:int | n >= 0} list_vt_cons (a, n+1) of (a, list_vt0ype_int_vtype (a, n)) | list_vt_nil (a, 0) of ()stadef list_vt = list_vt0ype_int_vtype




make_pairmake_pairmake_pairmake_pairmake_pair(* File: prelude/SATS/list_vt.sats *)fun{x:vt0p}list_vt_make_pair (x1: x, x2: x):<!wrt> list_vt (x, 2)

(* File: prelude/SATS/list_vt.sats *)fun{x:vt0p}list_vt_make_pair (x1: x, x2: x):<!wrt> list_vt (x, 2)




appendappendappendappendappend(* File: prelude/SATS/list_vt.sats *)fun{a:vt0p} list_vt_append {n1,n2:int} ( xs1: list_vt (INV(a), n1), xs2: list_vt (a, n2)) :<!wrt> list_vt (a, n1+n2)

(* File: prelude/SATS/list_vt.sats *)fun{a:vt0p} list_vt_append {n1,n2:int} ( xs1: list_vt (INV(a), n1), xs2: list_vt (a, n2)) :<!wrt> list_vt (a, n1+n2)




[][][][][](* File: prelude/SATS/list_vt.sats *)fun{x:t0p}list_vt_get_at{n:int} (xs: !list_vt (INV(x), n), i: natLt n):<> xoverload [] with list_vt_get_at(* File: prelude/basics_sta.sats *)typedef g1intBtw(tk:tk, lb:int, ub:int) = [i: int | lb <= i; i < ub] g1int (tk, i)typedef intBtw (lb:int, ub:int) = g1intBtw (int_kind, lb, ub)typedef natLt (n:int) = intBtw (0, n)

(* File: prelude/SATS/list_vt.sats *)fun{x:t0p}list_vt_get_at{n:int} (xs: !list_vt (INV(x), n), i: natLt n):<> xoverload [] with list_vt_get_at(* File: prelude/basics_sta.sats *)typedef g1intBtw(tk:tk, lb:int, ub:int) = [i: int | lb <= i; i < ub] g1int (tk, i)typedef intBtw (lb:int, ub:int) = g1intBtw (int_kind, lb, ub)typedef natLt (n:int) = intBtw (0, n)




reversereversereversereversereverse(* File: prelude/SATS/list_vt.sats *)fun{x:vt0p}list_vt_reverse{n:int} (xs: list_vt (INV(x), n)):<!wrt> list_vt (x, n)

(* File: prelude/SATS/list_vt.sats *)fun{x:vt0p}list_vt_reverse{n:int} (xs: list_vt (INV(x), n)):<!wrt> list_vt (x, n)




freefreefreefreefree(* File: prelude/basics_dyn.sats *)vtypedefList_vt (a:vt0p) = [n:int] list_vt (a, n)

(* File: prelude/SATS/list_vt.sats *)fun{x:t0p}list_vt_free (xs: List_vt (INV(x))):<!wrt> voidoverload free with list_vt_free

(* File: prelude/basics_dyn.sats *)vtypedefList_vt (a:vt0p) = [n:int] list_vt (a, n)








Japan ATS User GroupJapan ATS User GroupJapan ATS User GroupJapan ATS User GroupJapan ATS User Group

http://jats-ug.metasepi.org/http://jats-ug.metasepi.org/http://jats-ug.metasepi.org/http://jats-ug.metasepi.org/http://jats-ug.metasepi.org/

☆ In a parody of http://jaws-ug.jp/☆ In a parody of http://jaws-ug.jp/☆ In a parody of http://jaws-ug.jp/☆ In a parody of http://jaws-ug.jp/☆ In a parody of http://jaws-ug.jp/

☆ Push the Facebook like button, now!☆ Push the Facebook like button, now!☆ Push the Facebook like button, now!☆ Push the Facebook like button, now!☆ Push the Facebook like button, now!

☆ We translate ATS docs into Japanese☆ We translate ATS docs into Japanese☆ We translate ATS docs into Japanese☆ We translate ATS docs into Japanese☆ We translate ATS docs into Japanese

"ATSプログラミング入門""ATSプログラミング入門""ATSプログラミング入門""ATSプログラミング入門""ATSプログラミング入門"http://jats-ug.metasepi.org/doc/ATS2/INT2PROGINATS/index.htmlhttp://jats-ug.metasepi.org/doc/ATS2/INT2PROGINATS/index.htmlhttp://jats-ug.metasepi.org/doc/ATS2/INT2PROGINATS/index.htmlhttp://jats-ug.metasepi.org/doc/ATS2/INT2PROGINATS/index.htmlhttp://jats-ug.metasepi.org/doc/ATS2/INT2PROGINATS/index.html

"ATS公式Wikiの日本語訳""ATS公式Wikiの日本語訳""ATS公式Wikiの日本語訳""ATS公式Wikiの日本語訳""ATS公式Wikiの日本語訳"https://github.com/jats-ug/ATS-Postiats-wikihttps://github.com/jats-ug/ATS-Postiats-wikihttps://github.com/jats-ug/ATS-Postiats-wikihttps://github.com/jats-ug/ATS-Postiats-wikihttps://github.com/jats-ug/ATS-Postiats-wiki

"MLプログラマ向けATS言語ガイド""MLプログラマ向けATS言語ガイド""MLプログラマ向けATS言語ガイド""MLプログラマ向けATS言語ガイド""MLプログラマ向けATS言語ガイド"https://github.com/jats-ug/translate/blob/master/Web/cs.likai.org/ats/ml-programmers-guide-to-ats.mdhttps://github.com/jats-ug/translate/blob/master/Web/cs.likai.org/ats/ml-programmers-guide-to-ats.mdhttps://github.com/jats-ug/translate/blob/master/Web/cs.likai.org/ats/ml-programmers-guide-to-ats.mdhttps://github.com/jats-ug/translate/blob/master/Web/cs.likai.org/ats/ml-programmers-guide-to-ats.mdhttps://github.com/jats-ug/translate/blob/master/Web/cs.likai.org/ats/ml-programmers-guide-to-ats.md

Paper "Applied Type System"Paper "Applied Type System"Paper "Applied Type System"Paper "Applied Type System"Paper "Applied Type System"https://github.com/jats-ug/translate/raw/master/Paper/ATS-types03/ATS-types03-ja.pdfhttps://github.com/jats-ug/translate/raw/master/Paper/ATS-types03/ATS-types03-ja.pdfhttps://github.com/jats-ug/translate/raw/master/Paper/ATS-types03/ATS-types03-ja.pdfhttps://github.com/jats-ug/translate/raw/master/Paper/ATS-types03/ATS-types03-ja.pdfhttps://github.com/jats-ug/translate/raw/master/Paper/ATS-types03/ATS-types03-ja.pdf

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License of photos usedLicense of photos usedLicense of photos usedLicense of photos usedLicense of photos used* Creative Commons BBB | Flickr - Photo Sharing! https://www.flickr.com/photos/steren/2732488224 Copyright: 2008 Steren Giannini / License: CC BY 2.0* le coq / o galo de Barcelos | Flickr - Photo Sharing! https://www.flickr.com/photos/guymoll/311768037 Copyright: 2006 Guy MOLL / License: CC BY 2.0* news_twitter_facebook | Flickr - Photo Sharing! https://www.flickr.com/photos/lioman/4324501845 Copyright: 2010 lioman123 / License: CC BY-SA 2.0* Jordan shooting Jenna with shield | Flickr - Photo Sharing! https://www.flickr.com/photos/jasoneppink/80772834 Copyright: 2005 Jason Eppink / License: CC BY 2.0* Marsh Plaza, Boston University | Flickr - Photo Sharing! https://www.flickr.com/photos/hankzby/14122296866 Copyright: 2014 Henry Zbyszynski / License: CC BY 2.0* Love That Binds | Flickr - Photo Sharing! https://www.flickr.com/photos/enerva/12525888074 Copyright: 2014 Sonny Abesamis / License: CC BY 2.0

* Creative Commons BBB | Flickr - Photo Sharing! https://www.flickr.com/photos/steren/2732488224 Copyright: 2008 Steren Giannini / License: CC BY 2.0* le coq / o galo de Barcelos | Flickr - Photo Sharing! https://www.flickr.com/photos/guymoll/311768037 Copyright: 2006 Guy MOLL / License: CC BY 2.0* news_twitter_facebook | Flickr - Photo Sharing! https://www.flickr.com/photos/lioman/4324501845 Copyright: 2010 lioman123 / License: CC BY-SA 2.0* Jordan shooting Jenna with shield | Flickr - Photo Sharing! https://www.flickr.com/photos/jasoneppink/80772834 Copyright: 2005 Jason Eppink / License: CC BY 2.0* Marsh Plaza, Boston University | Flickr - Photo Sharing! https://www.flickr.com/photos/hankzby/14122296866 Copyright: 2014 Henry Zbyszynski / License: CC BY 2.0* Love That Binds | Flickr - Photo Sharing! https://www.flickr.com/photos/enerva/12525888074 Copyright: 2014 Sonny Abesamis / License: CC BY 2.0




Metasepi team meeting #17: Invariant captured by ATS's API

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Transcript of Metasepi team meeting #17: Invariant captured by ATS's API