Lisp-style C++ template meta programming

Matsenga Osiyanasiyana a Compiler: Lisp-Style C++ Template Metaprogramming

M'malo ambiri opangira mapulogalamu, C++ imadziwika chifukwa cha mphamvu zake komanso magwiridwe ake. Komabe, mkati mwa njira yake yophatikizira pali lingaliro lomwe limamveka ngati lachilendo: template metaprogramming (TMP). Ikatengedwera mopitilira muyeso, C ++ TMP imayamba kufanana ndi chilankhulo chothandizira payokha, chomwe chimagwira ntchito yonse panthawi yophatikiza. Zofanana ndi Lisp, chimodzi mwa zilankhulo zakale kwambiri komanso zodziwika bwino zamapulogalamu, ndizodabwitsa komanso zakuya. Njirayi imalola opanga kutsitsa mawerengedwe ovuta komanso malingaliro kuyambira nthawi yothamanga mpaka kuphatikizira nthawi, ndikupanga ma code abwino kwambiri komanso otetezeka. Kumvetsetsa njira ya Lisp iyi ndikofunika kwambiri kuti titsegule njira yatsopano yochotsera, mfundo yomwe timayamikira kwambiri ku Mewayz tikamamanga mabizinesi olimba, okhazikika.

Chiyankhulo Chopanga Mwangozi Mkati mwa C++

Ma tempulo a C++ adapangidwa poyambirira kuti alowe m'malo mophweka, monga kupanga `List` kapena `List`. Komabe, mulingo wa C++, pofunafuna zambiri, mwangozi adapanga chilankhulo cha Turing-complete. Izi zikutanthauza kuti mwachidziwitso, kuwerengera kulikonse komwe kungathe kuchitidwa ndi pulogalamu kungathenso kuchitidwa ndi C ++ compiler panthawi ya template instantiation process. Kupezeka kwa kuthekera uku kudapangitsa kubadwa kwa template metaprogramming. Zinapezeka kuti pogwiritsa ntchito luso la template, kubwereza, ndi magawo a template, munthu amatha kulemba mapulogalamu omwe wopangayo amapanga pomanga pulogalamu yanu. "Chilankhulo" cha nthawi yophatikizirachi chilibe zosinthika m'lingaliro lachikhalidwe; chikhalidwe chake chili mu magawo a template okha, ndipo mawonekedwe ake owongolera amatengera kubwereza komanso kusanja koyenera.

Kukumbatira Maganizo Ogwira Ntchito, Onga Lisp

Kuti mulembe bwino mametaprogram a ma template, munthu ayenera kukhala ndi malingaliro ogwirira ntchito, monga wopanga mapulogalamu a Lisp. Palibe malo osinthika kapena malupu munjira yachikale. M'malo mwake, chilichonse chimatheka chifukwa chobwerezabwereza komanso kusintha mitundu ndi kuphatikiza nthawi zonse. Taganizirani chitsanzo chosavuta: kuwerengera fakitale. Mu Lisp, mutha kugwiritsa ntchito ntchito yobwereza. Mu C++ TMP, njirayi ndi yofanana kwambiri, koma imagwira ntchito ndi mitundu ndi makhalidwe.

• Chidziwitso Chosasinthika: Monga momwe zilili ndi Lisp, deta mu TMP ndi yosasinthika. Kamodzi template parameter yakhazikitsidwa, singasinthidwe; mutha kupanga "zochitika" zatsopano ndi magawo osiyanasiyana.
• Recursion as Iteration: Popeza kulibe `kwa` kapena `while` malupu, kubwereranso ndiye njira yoyambira yobwereza ntchito. Template imadzitcha yokha ndi magawo osinthidwa mpaka gawo loyambira (kudzera mwaukadaulo wa ma template) lifikira.
• Kusintha Mitundu, Osati Makhalidwe Okha: Mbali yamphamvu kwambiri ya TMP ndikutha kuwerengera mitundu. Mutha kupanga mndandanda wamitundu, kuyang'ana zamtundu, ndikusankha mitundu kutengera momwe zinthu ziliri, zomwe zimathandizira njira zamphamvu zopangira ma generic.

Maganizowa amakakamiza kuganiza kosiyana, komwe kumayika patsogolo malingaliro ofotokozera kuposa masitepe ofunikira, zomwe zimapangitsa kuti pakhale khodi yolimba komanso yosamva zolakwika.

"Metaprogramming template kwenikweni ndi chinenero chogwira ntchito chomwe chili mkati mwa C ++. Ndi chida champhamvu, koma chimafunika kulingalira za mapulogalamu m'njira yosiyana-njira yomwe nthawi zambiri imakhala yosamvetsetseka komanso masamu." - Membala wa Komiti ya Miyezo ya C ++

Mapulogalamu Ogwiritsa Ntchito mu Modular System

Ngakhale chitsanzo cha factorial ndi chamaphunziro, mphamvu yeniyeni ya Lisp-style TMP imawala muzogwiritsira ntchito zomwe zimapindula ndi zero-runtime-overhead abstractions. Mwachitsanzo, itha kugwiritsidwa ntchito kupanga zida zokongoletsedwa kwambiri zamtundu womwe wapatsidwa, kutsimikizira masinthidwe ovuta panthawi yophatikiza, kapena kugwiritsa ntchito mapangidwe apamwamba kwambiri ngati Mapangidwe Otengera Ndondomeko. Pankhani ya nsanja ngati Mewayz, yomwe ikufuna kukhala bizinesi yokhazikika OS, njirazi ndizofunika kwambiri. Amatilola kupanga zigawo zikuluzikulu zomwe zimasinthasintha modabwitsa komanso zogwira ntchito mwapadera. Ma module a API atha kupangidwa pogwiritsa ntchito TMP kuti akhazikitse malamulo abizinesi ndi maubwenzi a data pamtundu wamtundu, kugwira masinthidwe olakwika nthawi yayitali pulogalamuyo isanatumizidwe. Chitetezo cha nthawi yophatikizikachi ndichofunika kwambiri popanga makina odalirika, owopsa omwe mabizinesi amadalira.

Chisinthiko ndi Tsogolo lokhala ndi `constexpr`

Kumayambiriro kwa C++ TMP nthawi zambiri kunkatsutsidwa chifukwa cha mawu ake osavuta komanso nthawi yophatikizira pang'onopang'ono. Pozindikira izi, komiti yoyang'anira miyezo ya C ++ yakhazikitsanso nthawi yolumikizana ndi otukula, makamaka `constexpr` ndipo posachedwa, `consteval`. Izi zimalola mawerengedwe ambiri omwe poyamba ankafuna kuti ma template ovuta alembedwe pogwiritsa ntchito mawu odziwika bwino, ofunikira a C ++ omwe amachitidwa panthawi yosonkhanitsa. Komabe, njira ya Lisp-style TMP imakhalabe yofunikira pamawerengedwe otengera mtundu ndi zochitika zomwe zimafunikira kuwongolera kofunikira kwambiri pakukhazikitsa ma template. Wopanga C++ wamakono tsopano ali ndi zida zambiri, kuchokera ku TMP yachikhalidwe kupita ku `constexpr` ntchito, zomwe zimawalola kusankha chida choyenera pantchitoyo ndikulemba zoyeretsa, ma metaprogramu okhazikika.

Mafunso Ofunsidwa Kawirikawiri

Matsenga Osiyanasiyana a Compiler: Lisp-Style C++ Template Metaprogramming

M'malo ambiri opangira mapulogalamu, C++ imadziwika chifukwa cha mphamvu zake komanso magwiridwe ake. Komabe, mkati mwa njira yake yophatikizira pali lingaliro lomwe limamveka ngati lachilendo: template metaprogramming (TMP). Ikatengedwera mopitilira muyeso, C ++ TMP imayamba kufanana ndi chilankhulo chothandizira payokha, chomwe chimagwira ntchito yonse panthawi yophatikiza. Zofanana ndi Lisp, chimodzi mwa zilankhulo zakale kwambiri komanso zodziwika bwino zamapulogalamu, ndizodabwitsa komanso zakuya. Njirayi imalola opanga kutsitsa mawerengedwe ovuta komanso malingaliro kuyambira nthawi yothamanga mpaka kuphatikizira nthawi, ndikupanga ma code abwino kwambiri komanso otetezeka. Kumvetsetsa njira ya Lisp iyi ndikofunika kwambiri kuti titsegule njira yatsopano yochotsera, mfundo yomwe timayamikira kwambiri ku Mewayz tikamamanga mabizinesi olimba, okhazikika.

Chiyankhulo Chopanga Mwangozi Mkati mwa C++

Ma tempulo a C++ adapangidwa poyambirira kuti alowe m'malo mwachidule, monga kupanga `Mndandanda` kapena `Mndandanda`. Komabe, mulingo wa C++, pofunafuna zambiri, mwangozi adapanga chilankhulo cha Turing-complete. Izi zikutanthauza kuti mwachidziwitso, kuwerengera kulikonse komwe kungathe kuchitidwa ndi pulogalamu kungathenso kuchitidwa ndi C ++ compiler panthawi ya template instantiation process. Kupezeka kwa kuthekera uku kudapangitsa kubadwa kwa template metaprogramming. Zinapezeka kuti pogwiritsa ntchito luso la template, kubwereza, ndi magawo a template, munthu amatha kulemba mapulogalamu omwe wopangayo amapanga pomanga pulogalamu yanu. "Chilankhulo" cha nthawi yophatikizirachi chilibe zosinthika m'lingaliro lachikhalidwe; chikhalidwe chake chili mu magawo a template okha, ndipo mawonekedwe ake owongolera amatengera kubwereza komanso kusanja koyenera.

Kukumbatira Maganizo Ogwira Ntchito, Onga Lisp

Kuti mulembe bwino mametaprogram a ma template, munthu ayenera kukhala ndi malingaliro ogwirira ntchito, monga wopanga mapulogalamu a Lisp. Palibe malo osinthika kapena malupu munjira yachikale. M'malo mwake, chilichonse chimatheka chifukwa chobwerezabwereza komanso kusintha mitundu ndi kuphatikiza nthawi zonse. Taganizirani chitsanzo chosavuta: kuwerengera fakitale. Mu Lisp, mutha kugwiritsa ntchito ntchito yobwereza. Mu C++ TMP, njirayi ndi yofanana kwambiri, koma imagwira ntchito ndi mitundu ndi makhalidwe.

Mapulogalamu Ogwiritsa Ntchito mu Modular System

Ngakhale chitsanzo cha factorial ndi chamaphunziro, mphamvu yeniyeni ya Lisp-style TMP imawala muzogwiritsira ntchito zomwe zimapindula ndi zero-runtime-overhead abstractions. Mwachitsanzo, itha kugwiritsidwa ntchito kupanga zida zokongoletsedwa kwambiri zamtundu womwe wapatsidwa, kutsimikizira masinthidwe ovuta panthawi yophatikiza, kapena kugwiritsa ntchito mapangidwe apamwamba kwambiri ngati Mapangidwe Otengera Ndondomeko. Pankhani ya nsanja ngati Mewayz, yomwe ikufuna kukhala bizinesi yokhazikika OS, njirazi ndizofunika kwambiri. Amatilola kupanga zigawo zikuluzikulu zomwe zimasinthasintha modabwitsa komanso zogwira ntchito mwapadera. Ma module a API atha kupangidwa pogwiritsa ntchito TMP kuti akhazikitse malamulo abizinesi ndi maubwenzi a data pamtundu wamtundu, kugwira masinthidwe olakwika nthawi yayitali pulogalamuyo isanatumizidwe. Chitetezo cha nthawi yophatikizikachi ndichofunika kwambiri popanga makina odalirika, owopsa omwe mabizinesi amadalira.

Chisinthiko ndi Tsogolo lokhala ndi `constexpr`

Kumayambiriro kwa C++ TMP nthawi zambiri kunkatsutsidwa chifukwa cha mawu ake osavuta komanso nthawi yophatikizira pang'onopang'ono. Pozindikira izi, komiti yoyang'anira miyezo ya C ++ yakhazikitsanso nthawi yolumikizana ndi otukula, makamaka `constexpr` ndipo posachedwa, `consteval`. Izi zimalola mawerengedwe ambiri omwe poyamba ankafuna kuti ma template ovuta alembedwe pogwiritsa ntchito mawu odziwika bwino, ofunikira a C ++ omwe amachitidwa panthawi yosonkhanitsa. Komabe, njira ya Lisp-style TMP imakhalabe yofunikira pamawerengedwe otengera mtundu ndi zochitika zomwe zimafunikira kuwongolera kofunikira kwambiri pakukhazikitsa ma template. Wopanga C++ wamakono tsopano ali ndi zida zambiri, kuchokera ku TMP yachikhalidwe kupita ku `constexpr` ntchito, zomwe zimawalola kusankha chida choyenera pantchitoyo ndikulemba zoyeretsa, ma metaprogramu okhazikika.