Β«Ulimi lokuhlela olukhulu kakhulu olwake lwadalwaΒ«
- Alan Kay, "on Lisp"
Ngenkathi uMcCarthy enza i-Lisp ngasekupheleni kwawo-1950, yayihluke kakhulu ezilimini ezikhona, ezibaluleke kakhulu kuzo .
U-Lisp wethule imibono emisha eyisishiyagalolunye:
1. Imibandela. Izitatimende ezinemibandela ziwukwakhiwa uma-ke-okunye. Manje sizithatha kalula. Kade McCarthy ngesikhathi kuthuthukiswa uLisp. (I-Fortran ngaleso sikhathi yayinezitatimende ze-goto kuphela, ezihambisana eduze nomyalelo wegatsha mayelana ne-hardware engaphansi.) UMcCarthy, ngenkathi esekomitini le-Algol, wanikela ngezimo ze-Algol, kusukela lapho zasakazekela kwezinye izilimi.
2. Uhlobo lomsebenzi. Ku-Lisp, imisebenzi yizinto ezisezingeni lokuqala - ziwuhlobo lwedatha, njengezinombolo, izintambo, njll., futhi zinokumelwa okungokoqobo, zingagcinwa eziguquguqukayo, zingadluliswa njengezimpikiswano, njll.
3. Ukuphindaphinda. I-recursion, yebo, yayikhona njengomqondo wezibalo ngaphambi kwe-Lisp, kodwa i-Lisp yayiwulimi lokuqala lokuhlela ukuyisekela. (Lokhu mhlawumbe kushiwo ekudaleni imisebenzi njengezinto ezisezingeni lokuqala.)
4. Umqondo omusha wokuguquguquka. Ku-Lisp, zonke izinto eziguquguqukayo ziyizinkomba ezisebenzayo. Amanani ayizinhlobo ezinazo, hhayi okuguquguqukayo, futhi ukwaba noma ukubopha okuguquguqukayo kusho ukukopisha izinkomba, hhayi lokho ezikhomba kukho.
5. Ukuqoqwa kukadoti.
6. Izinhlelo ezakhiwe izinkulumo. Izinhlelo ze-Lisp ziyizihlahla zezinkulumo, ngayinye yazo ebuyisela inani. (Ezinye izinkulumo ze-Lisp zingabuyisela amanani amaningi.) Lokhu kuqhathanisa ne-Fortran nezinye izilimi eziningi eziphumelelayo ezihlukanisa phakathi βkwezinkulumoβ kanye βnezitatimende.β
Bekungokwemvelo ukuba nalo mehluko e-Fortran ngoba ulimi belugxile emugqeni (akumangazi olimini olufomethi yalo yokufaka eyikhadi elihlatshiwe). Awukwazanga ukuba nezitatimende ezifakiwe. Futhi inqobo nje uma udinga izinkulumo zezibalo ukuze usebenze, kwakungekho phuzu lokuba nanoma yini enye ibuyisele inani ngoba kungase kungabikho lutho olulindele ukubuyiselwa.
Imingcele yasuswa ngokufika kwezilimi ezihlelekile, kodwa ngaleso sikhathi kwase kwephuze kakhulu. Umehluko phakathi kwezinkulumo nezitatimende usuvele usunguliwe. Yadlula isuka eFortran yaya e-Algol futhi yadlulela ezizukulwaneni zabo.
Uma ulimi lwenziwe izinkulumo ngokuphelele, ungaqamba izisho nganoma iyiphi indlela oyifunayo. Ungabhala noma yikuphi (usebenzisa i-syntax )
(if foo (= x 1) (= x 2))noma
(= x (if foo 1 2))7. Uhlobo lophawu. Izinhlamvu zihlukile kuchungechunge, lapho ungabheka ukulingana ngokuqhathanisa izinkomba.
8. Isaziso sekhodi usebenzisa izihlahla zezimpawu.
9. Ulimi lonke luhlala lukhona. Awukho umehluko osobala phakathi kwesikhathi sokufunda, isikhathi sokuhlanganisa kanye nesikhathi sokusebenza. Ungakwazi ukuhlanganisa noma usebenzise ikhodi ngenkathi ufunda, noma ufunde noma uqhube ikhodi ngenkathi uhlanganisa, noma ufunde noma uhlanganise ikhodi ngenkathi isebenza.
Ikhodi esebenzayo ngenkathi ufunda ivumela abasebenzisi ukuthi bahlele kabusha i-syntax ka-Lisp; ukusebenzisa ikhodi ngesikhathi sokuhlanganiswa kuyisisekelo sama-macros; ukuhlanganiswa kwesikhathi sokusebenza kuyisisekelo sokusebenzisa i-Lisp njengolimi olunwetshiwe ezinhlelweni ezifana ne-Emacs; futhi ekugcineni, ukufunda kwesikhathi sokusebenza kuvumela izinhlelo ukuxhumana kusetshenziswa i-s-expressions, umbono osanda kusungulwa kabusha ku-XML.
isiphetho
Ngenkathi i-Lisp isungulwa okokuqala, le mibono yayikude kakhulu nezinqubo ezijwayelekile zokuhlela ezazishiwo yi-hardware etholakala ngasekupheleni kwawo-1950.
Ngokuhamba kwesikhathi, ulimi olumisiwe, oluhlanganiswe impumelelo yezilimi ezidumile, kancane kancane lwaguqukela ku-Lisp. Amaphuzu 1-5 manje asemukelwa kabanzi. Iphuzu lesi-6 seliqala ukubonakala endaweni evamile. Ku-Python, kukhona isigatshana sesi-7 ngandlela-thile, nakuba ingekho i-syntax efanelekile. Into engu-8, (ngento engu-9) eyenza ama-macros abe khona ku-Lisp, isase-Lisp kuphela, mhlawumbe ngenxa yokuthi (a) idinga labo bakaki noma into embi ngokulinganayo, futhi (b) uma wengeza lokhu kwanda kwakamuva kwamandla, ungakwazi asisasho ukuthi sisungule ulimi olusha, kodwa sesisungule ulimi lwesigodi olusha lwesiLisp; -)
Nakuba lokhu kuwusizo kubahleli bezinhlelo besimanje, kuyamangaza ukuchaza i-Lisp ngokomehluko wayo kumasu angahleliwe asetshenziswa kwezinye izilimi. Lokhu kungase kungabi yilokho uMakhathini ayekucabanga. I-Lisp yayingaklanyelwe ukulungisa amaphutha e-Fortran; kubonakale kakhulu njengomkhiqizo wokuzama .
Source: www.habr.com