Ulimi lohlelo lwePascal lubungaza iminyaka engama-50

I-Pascal ulimi lokuhlela olwaqala ukushicilelwa ngo-1970, lolu bekungulimi lohlelo owazalwa eminyakeni yokuqala yohlelo oluhlelekile futhi eba neminyaka engama-50.

I-Pascal, isetshenziselwa ukuthuthukiswa kwesoftware futhi ikhona kakhulu kwezemfundo. Umlingisi wakhe, UNiklaus Wirth, wakhuthazwa ngumsebenzi wakhe wangaphambilini ku-Algol W. ngawo wayenganelisekile ngokuphelele. Eqinisweni, ngasekupheleni kweminyaka yama-1950, iFortran (FORmula TRANslator) yezicelo zesayensi kanye neCobol (Ulimi Olujwayelekile Lwebhizinisi) ngezinhlelo zokuhweba zazibalulekile.

Ngo 1960, ikomidi lomhlaba jikelele ushicilele ulimi lwe-Algol 60, bekungokokuqala ukuthi ulimi luchazwe ngokwakhiwa okwakhiwe emfushane nange-syntax eqondile nesemthethweni.

Cishe eminyakeni emibili kamuva, abazali bakhe banquma ukulungisa okuthile kanye nezithuthukisi zolimi, njengoba i-Algol 60 yayihloselwe kuphela ikhompyutha yesayensi. Ngakho-ke, iqembu elisebenzayo lakhiwa le phrojekthi.

Nokho, akubona bonke abavuma ukucaciswa okusha lokho kuzongezwa olimini, okuholele ekutheni kube namaqembu amabili ngaphakathi komphakathi.

Enye yazo yayihloselwe ulimi lwesibili ngemibono emisha ngokuphelele, engahloliwe nokuguquguquka kwemvelo okusakazekile. I-Wirth ibingeyona ingxenye yaleli qembu elincane isiphakamiso salo samukelwa futhi kamuva sazala i-Algol 68.

Ushiye iqembu cishe ngonyaka we-1966 wabe eseqala, kanye nabanye abafundi baseStanford University PhD, bakha umhlanganisi wesiphakamiso asenzile. Umphumela waba ulimi lwe-Algol W ngo-1967.

Uthe i-Algol W ibisetshenziswa kumakhompyutha amaningi we-IBM mainframe. UWirth ulandisa ukuthi i-Algol W yayiphumelele kakhulu uma iqhathaniswa ne-Algol 68. "I-Algol 68 eyingqophamlando yavela, yase isheshe yafihla ngaphansi kwesisindo sayo, yize eminye imiqondo yayo isekhona ngezilimi ezalandela," esho.

Nokho, U-Algol W wayengaphelele ekuthandeni kwakhe, njengoba isazoqukethe ukuzibophezela okuningi kakhulu, ngoba ivela kwikhomishini.

UWirth wabe esethatha umsebenzi omusha futhi wakwazi ukuthuthukisa ulimi olusha ngokuphelele ngokwezintandokazi zakhe, azibiza ngokuthi uPascal. Kwisimo akuso kwi-website ye-Association for Computing Machinery (ACM), okuyinhlangano engenzi nzuzo yamazwe omhlaba ezinikele ekusebenziseni ikhompyutha, uthe lo msebenzi ugcwele isimanga ngaye nokuthi yena nabasebenzi bakhe babe nesipiliyoni esibi ngesikhathi sentuthuko.

Babefuna ukuchaza umhlanganisi ePascal, bahumushe ngesandla eFortran, futhi ekugcineni bahlanganise owokuqala nowesibili.

UWirth uthe lokhu kube ukwehluleka okukhulu, ikakhulukazi ngenxa yokushoda kwezinhlaka zedatha eFortran, okwenza ukuhumusha kube nzima kakhulu.

Kodwa-ke, umzamo wesibili waphumelela, lapho esikhundleni seFortran, kwasetshenziswa ulimi lweScallop. Qaphela ukuthi uWirth wayenguprofesa osizayo eStanford University kusuka ngo-1963 kuya ku-1967, wabe ese-University of Zurich. Wabe eseba nguprofesa wekhompyutha e-ETHZ (Swiss Federal Institute of Technology eZurich), ngaphambi kokuthatha umhlalaphansi ngo-Ephreli 1999.

UWirth uthe, njengomanduleli wayo u-Algol 60, UPascal unencazelo eqondile nezinye izisekelo ezinenzuzo. Imiyalo ichaza ukwabiwa kwamanani kokuguquguqukayo nokwenziwa okunemibandela nokuphindaphindwayo. Yini enye, kwakukhona izinqubo futhi zaziphinda. Ngokusho kombhali, izinhlobo zedatha nezinhlaka zaziwukunwetshwa okubalulekile, futhi izinhlobo zazo zedatha eyisisekelo zazingama-integer kanye nama-reals, amanani we-Boolean, abalingiswa, kanye nokubalwa (kwama-constants).

Izakhiwo kwakungu-arrays, amarekhodi, amafayela (ukulandelana), nezikhombi. Izinqubo zifake izinhlobo ezimbili zamapharamitha: amapharamitha wenani nemingcele eguquguqukayo. Izinqubo zingasetshenziswa ziphindaphindwe.

Okubaluleke kakhulu, wathi, bekungumqondo okuyo yonke indawo wohlobo lwedatha.

Umsebenzi ngamunye oqhubekayo, oguquguqukayo, noma owenziwe wawungowohlobo olungaguquki nolumile. Ngakho-ke izinhlelo zifaka phakathi ukusweleka okuningi umhlanganisi angakusebenzisa ukuhlola ukungaguquguquki kwezinhlobo zedatha. Lokhu kusize ukuthola amaphutha ngaphambi kokuqalisa uhlelo.

Umthombo: https://cacm.acm.org/