Lisp-stil C ++ inyandikorugero meta gahunda

Ubwoko butandukanye bwabakusanya Magic: Lisp-Style C ++ Inyandikorugero Metaprogramming

Mubice binini byiterambere rya software, C ++ izwiho imbaraga mbisi n'imikorere. Nyamara, yashyizwe mubikorwa byayo bigoye byo gukusanya ibeshya ni paradigima yumva ari umunyamahanga: template metaprogramming (TMP). Iyo bijyanwe muburyo bukabije, C ++ TMP itangira kumera nkururimi rukora programme muburyo bwarwo, rumwe rukora rwose mugihe cyo gukusanya. Ibisa na Lisp, rumwe mundimi za kera kandi zikomeye cyane zo gutangiza porogaramu, ziratangaje kandi zimbitse. Ubu buryo butuma abaterankunga bapakurura comptabilite hamwe na logique kuva mugihe cyo gukora kugeza igihe cyo gukora, gukora code nziza kandi yubwoko-umutekano. Gusobanukirwa ubu buryo bwa Lisp ni urufunguzo rwo gufungura urwego rushya rwa abstraction, ihame duha agaciro cyane Mewayz mugihe twubaka sisitemu yubucuruzi ikomeye, yubusa.

Ururimi rwo Gutegura Impanuka Muri C ++

C ++ inyandikorugero zakozwe muburyo bwambere bwo gusimbuza ubwoko bworoshye, nko gukora `Urutonde ` cyangwa `Urutonde `. Ariko, igipimo cya C ++, mugukurikirana rusange, kubwimpanuka yakoze Turing-yuzuye-ururimi. Ibi bivuze ko mubyukuri, ibarwa iyo ari yo yose ishobora gukorwa na porogaramu irashobora no gukorwa na C ++ compiler mugihe cyo gutangiza icyitegererezo. Ivumburwa ryubu bushobozi ryatumye havuka icyitegererezo metaprogramming. Byagaragaye ko ukoresheje inyandikorugero yihariye, recursion, hamwe nibipimo byerekana, umuntu yashoboraga kwandika progaramu uwatunganije akora mugihe yubaka porogaramu. Gukusanya-igihe "ururimi" nta gihinduka muburyo gakondo; leta yacyo igizwe nicyitegererezo cyibipimo ubwabyo, kandi imiterere yubugenzuzi bushingiye kubisubiramo no gukusanya ibintu.

Kwakira Imikorere, Lisp-imeze nka Mindset

Kugira ngo wandike neza inyandikorugero metaprogrammes, umuntu agomba gufata imitekerereze ya programme ikora, cyane nka Lisp programmer. Nta leta ihindagurika cyangwa izunguruka muburyo busanzwe. Ahubwo, ibintu byose bigerwaho binyuze muri recursion hamwe na manipulation yubwoko hamwe no gukusanya-igihe gihamye. Suzuma urugero rworoshye: kubara ibintu bifatika. Muri Lisp, urashobora gukoresha imikorere isubiramo. Muri C ++ TMP, inzira irasa cyane, ariko ikorana nubwoko nagaciro.

• Amakuru adahinduka: Nkuko muri Lisp, amakuru muri TMP ntahinduka. Inyandikorugero imaze gushyirwaho, ntishobora guhinduka; urashobora gukora gusa "ingero" nshya hamwe nibintu bitandukanye.
• Kwisubiramo nka Iteration: Kubera ko nta `for` cyangwa` mugihe` izunguruka, recursion nuburyo bwibanze bwo gusubiramo ibikorwa. Inyandikorugero yiyita hamwe n'ibipimo bigezweho kugeza urubanza shingiro (binyuze mu cyitegererezo cyihariye) rugeze.
• Gukoresha Ubwoko, Ntabwo Indangagaciro gusa: Ikintu gikomeye cyane cya TMP nubushobozi bwacyo bwo kubara nubwoko. Urashobora gukora urutonde rwubwoko, ukareba ubwoko bwimiterere, hanyuma ugahitamo ubwoko bushingiye kumiterere, bigafasha tekinike rusange yo gutangiza gahunda.

Iyi paradigima ihatira uburyo butandukanye bwo gutekereza, bumwe bushyira imbere logique yo gutangaza kuruta intambwe ziteganijwe, biganisha kuri code ikomeye kandi irwanya amakosa.

. - Umunyamuryango wa C ++ Ubuziranenge

Porogaramu Ifatika muri Moderi Sisitemu

Mugihe urugero rufatika ari amasomo, imbaraga nyazo za Lisp-stil ya TMP irabagirana mubikorwa bifatika byunguka zeru-runtime-hejuru-gukuramo. Kurugero, irashobora gukoreshwa kugirango habeho uburyo bwiza cyane bwamakuru yihariye yihariye yubwoko runaka, kugirango yemeze ibishushanyo bigoye mugihe cyo gukusanya, cyangwa gushyira mubikorwa ubuhanga buhanitse nka Politiki ishingiye ku gishushanyo. Mu rwego rwa platform nka Mewayz, igamije kuba OS yubucuruzi bwa modular, ubwo buhanga ni ntagereranywa. Baratwemerera kubaka ibice byingenzi byoroshye guhinduka kandi bikora neza bidasanzwe. API ya module irashobora gushushanywa ukoresheje TMP kugirango yubahirize amategeko yubucuruzi nubusabane bwamakuru kurwego rwubwoko, ifata ibishobora kubaho nabi mbere yuko software ikorwa. Umutekano wo gukusanya-igihe ningirakamaro mu kubaka sisitemu yizewe, yagutse ubucuruzi bushingiye.

Ubwihindurize nigihe kizaza hamwe na `constexpr`

Kera C ++ TMP yakunze kunengwa kubisobanuro byayo byihuta hamwe nigihe cyo gukusanya buhoro. Kumenya ibi, komite ngenderwaho ya C ++ imaze gushyiraho byinshi-biteza imbere-guteranya-igihe cyo kuranga-igihe, cyane cyane `constexpr` na vuba aha,` consteval`. Ibiranga byemerera kubara byinshi byigeze bisabwa bigoye byerekana inyandikorugero yanditswe ukoresheje ibimenyerewe, byingirakamaro C ++ syntax ikora mugihe cyo gukusanya. Nyamara, uburyo bwa Lisp-buryo bwa TMP burakomeza kuba ingirakamaro kubwoko bushingiye kubara hamwe na ssenariyo isaba igenzurwa ryibanze kubikorwa byihuta. Iterambere rya kijyambere rya C ++ ubu rifite urutonde rwibikoresho, kuva muri TMP gakondo kugeza kuri `constexpr` imikorere, ibemerera guhitamo igikoresho cyiza kumurimo no kwandika isuku, ikoreshwa neza na metaprogramu.

Ibibazo bikunze kubazwa

Ubwoko butandukanye bwabakusanya Magic: Lisp-Style C ++ Inyandikorugero Metaprogramming

Mubice binini byiterambere rya software, C ++ izwiho imbaraga mbisi n'imikorere. Nyamara, yashyizwe mubikorwa byayo bigoye byo gukusanya ibeshya ni paradigima yumva ari umunyamahanga: template metaprogramming (TMP). Iyo bijyanwe muburyo bukabije, C ++ TMP itangira kumera nkururimi rukora programme muburyo bwarwo, rumwe rukora rwose mugihe cyo gukusanya. Ibisa na Lisp, rumwe mundimi za kera kandi zikomeye cyane zo gutangiza porogaramu, ziratangaje kandi zimbitse. Ubu buryo butuma abaterankunga bapakurura comptabilite hamwe na logique kuva mugihe cyo gukora kugeza igihe cyo gukora, gukora code nziza kandi yubwoko-umutekano. Gusobanukirwa ubu buryo bwa Lisp ni urufunguzo rwo gufungura urwego rushya rwa abstraction, ihame duha agaciro cyane Mewayz mugihe twubaka sisitemu yubucuruzi ikomeye, yubusa.

Ururimi rutunguranye ruri muri C ++

C ++ inyandikorugero zakozwe muburyo bwambere bwo gusimbuza ubwoko bworoshye, nko gukora "Urutonde" cyangwa "Urutonde". Ariko, igipimo cya C ++, mugukurikirana rusange, kubwimpanuka yakoze Turing-yuzuye-ururimi. Ibi bivuze ko mubyukuri, ibarwa iyo ari yo yose ishobora gukorwa na porogaramu irashobora no gukorwa na C ++ compiler mugihe cyo gutangiza icyitegererezo. Ivumburwa ryubu bushobozi ryatumye havuka icyitegererezo metaprogramming. Byagaragaye ko ukoresheje inyandikorugero yihariye, recursion, hamwe nibipimo byerekana, umuntu yashoboraga kwandika progaramu uwatunganije akora mugihe yubaka porogaramu. Gukusanya-igihe "ururimi" nta gihinduka muburyo gakondo; leta yacyo igizwe nicyitegererezo cyibipimo ubwabyo, kandi imiterere yubugenzuzi bushingiye kubisubiramo no gukusanya ibintu.

Kwakira Imikorere, Lisp-imeze nka Mindset

Kugira ngo wandike neza inyandikorugero metaprogrammes, umuntu agomba gufata imitekerereze ya programme ikora, cyane nka Lisp programmer. Nta leta ihindagurika cyangwa izunguruka muburyo busanzwe. Ahubwo, ibintu byose bigerwaho binyuze muri recursion hamwe na manipulation yubwoko hamwe no gukusanya-igihe gihamye. Suzuma urugero rworoshye: kubara ibintu bifatika. Muri Lisp, urashobora gukoresha imikorere isubiramo. Muri C ++ TMP, inzira irasa cyane, ariko ikorana nubwoko nagaciro.

Porogaramu Ifatika muri Sisitemu Modular

Mugihe urugero rufatika ari amasomo, imbaraga nyazo za Lisp-stil ya TMP irabagirana mubikorwa bifatika byunguka zeru-runtime-hejuru-gukuramo. Kurugero, irashobora gukoreshwa kugirango habeho uburyo bwiza cyane bwamakuru yihariye yihariye yubwoko runaka, kugirango yemeze ibishushanyo bigoye mugihe cyo gukusanya, cyangwa gushyira mubikorwa ubuhanga buhanitse nka Politiki ishingiye ku gishushanyo. Mu rwego rwa platform nka Mewayz, igamije kuba OS yubucuruzi bwa modular, ubwo buhanga ni ntagereranywa. Baratwemerera kubaka ibice byingenzi byoroshye guhinduka kandi bikora neza bidasanzwe. API ya module irashobora gushushanywa ukoresheje TMP kugirango yubahirize amategeko yubucuruzi nubusabane bwamakuru kurwego rwubwoko, ifata ibishobora kubaho nabi mbere yuko software ikorwa. Umutekano wo gukusanya-igihe ningirakamaro mu kubaka sisitemu yizewe, yagutse ubucuruzi bushingiye.

Ubwihindurize nigihe kizaza hamwe na `constexpr`

Kera C ++ TMP yakunze kunengwa kubisobanuro byayo byihuta hamwe nigihe cyo gukusanya buhoro. Kumenya ibi, komite ngenderwaho ya C ++ imaze gushyiraho byinshi-biteza imbere-guteranya-igihe cyo kuranga-igihe, cyane cyane `constexpr` na vuba aha,` consteval`. Ibiranga byemerera kubara byinshi byigeze bisabwa bigoye byerekana inyandikorugero yanditswe ukoresheje ibimenyerewe, byingirakamaro C ++ syntax ikora mugihe cyo gukusanya. Nyamara, uburyo bwa Lisp-buryo bwa TMP burakomeza kuba ingirakamaro kubwoko bushingiye kubara hamwe na ssenariyo isaba igenzurwa ryibanze kubikorwa byihuta. Iterambere rya kijyambere rya C ++ ubu rifite urutonde rwibikoresho, kuva muri TMP gakondo kugeza kuri `constexpr` imikorere, ibemerera guhitamo igikoresho cyiza kumurimo no kwandika isuku, ikoreshwa neza na metaprogramu.