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Pascal. 1130379007 Suhua Lei. NIKLAUS WIRTH. Known for Algol W, Euler,  Pascal , Modula,  Modula-2,Oberon,  Oberon-2,Oberon-07,  Oberon System. BORN February 15, 1934  (age 80) Winterthur, Switzerland Citizenship Switzerland.

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pascal

Pascal

1130379007

Suhua Lei

slide2

NIKLAUS WIRTH

Known for

Algol W, Euler, Pascal,Modula, Modula-2,Oberon, Oberon-2,Oberon-07, Oberon System

BORN

February 15, 1934 (age 80)Winterthur, Switzerland

Citizenship

Switzerland

Notable Awards SIGPLAN Programming Languages Achievement AwardFellow of the Computer History MuseumMarcel Benoist Prize (1989) Turing Award

a famous book
A Famous Book

Algorithms

Data Structures

Programs

who influences its birth
Who influences its birth?

1958

ALGOL58

Algol Doesn’t Have Enough Data Types!

1960

ALGOL60

1966

ALGOL W

1970

PASCAL

data types1
Data Types
  • Complex types can be constructed from simple types:
programming paradigm
Programming Paradigm
  • Imperative, procedural
    • the flow of control is structured into standard statements, usually without \'goto\' commands.
  • Object Pascal support multiple paradigms
    • Programs written in Object Pascal can be purely procedural, or purely object-oriented, or contain elements of both paradigms
type system
Type system
  • It’s statically typed
  • Its type system has been described as "too strong"
    • Eg: the size of an array or string is part of its type, making some programming tasks difficult
    • Java > Pascal > C
  • It’s safe except two conditions
    • Function as parameter
    • Using unsigned variant record type
conclusion characteristic
Conclusion:characteristic
  • 严格的结构化形式;
  • 丰富完备的数据类型;
  • 运行效率高;
  • 查错能力强。
conclusion disadvantages
Conclusion:disadvantages
  • 传统PASCAL的标准库中缺乏对网络编程的支持,并且仅通过自带的graph单元难以实现较好的图形界面(GUI),这些缺点大多需要嵌入汇编语言代码才能得到解决,缺乏与机器语言的接口。
  • 与面向对象的语言相比,不利于大型软件的开发。
  • 推广了C语言的Brian Kernighan在1981年《Why Pascal Is Not My Favourite Programming Language》对Pascal提出了严厉的抨击。
applications
Applications
  • GCC,Gnu C编译器,最初是用Pascal的一种方言Pastel编写的
  • Pascal是Apple Lisa和早期Mac开发使用的高级语言
  • 流行的排版系统TeX是由高德纳使用基于DECPDP-10 Pascal的最初文学编程系统WEB编写的
  • Object Pascal仍然广泛用于开发像Skype这样的Windows应用
  • … …
delphi
Delphi的没落
  • Object Pascal并没有像C/C++那样成为业内标准
  • 人才流失,与内部决策失误。Delphi之父AndersHejlsberg离开Borland去了微软,导致Delphi的编译器有三年的时间无人敢动,因为AndersHejlsberg完全使用汇编实现的编译器,无人能够看懂。
  • 市场转变开发市场现在更注重B/S结构的应用,桌面应用正在大幅减少,Delphi显然不是一个理想的WEB开发语言。
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