Early pascal compilers

History Pascal, named in honor of the French mathematician and philosopher Blaise Pascalwas developed by Niklaus Wirth. Initially, Pascal was largely, but not exclusively, intended to teach students structured programming. Variants of Pascal have also frequently been used for everything from research projects to PC games and embedded systems. Newer Pascal compilers exist which are widely used.

Early pascal compilers

Earlier efforts[ edit ] Much of the history of computer language design during the s traces its history to the ALGOL 60 language. ALGOL was developed during the s with the explicit goal to be able to clearly describe algorithms.

It included a number of features for structured programming that remain common in languages to this day. Shortly after its introduction, in Wirth began working on his dissertation with Helmut Weber on the Euler programming language. Its primary goal was to add dynamic lists and types, allowing it to be used in roles similar to Lisp.

The language was published in By this time, a number of problems in ALGOL had been identified, notably the lack of a standardized string system.

The group tasked with maintaining the language had begun the ALGOL X process to identify improvements, calling for submissions.

Wirth and Tony Hoare submitted a conservative set of modifications to add strings and clean up some of the syntax.

Early pascal compilers

The complexity of this language led to considerable difficulty producing high-performance compilers, and it was not widely used in the industry. This left an opening for newer languages.

Pascal[ edit ] Pascal was influenced by the ALGOL W efforts, with the explicit goals of producing a language that would be efficient both in the compiler and at run-time, allow for the development of well-structured programs, and to be useful for teaching students structured programming.

One of the early successes for language was the introduction of UCSD Pascala version that ran on a custom operating system that could be ported to different platforms.

Early pascal compilers

A key platform was the Apple IIwhere it saw widespread use. This led to the use of Pascal becoming the primary high-level language used for development in the Apple Lisaand later, the Macintosh. Parts of the original Macintosh operating system were hand-translated into Motorola assembly language from the Pascal sources.

Apollo Computer used Pascal as the systems programming language for its operating systems beginning in Variants of Pascal have also frequently been used for everything from research projects to PC games and embedded systems.

Newer Pascal compilers exist which are widely used. This led initially to Clascalintroduced in As the Lisa program faded and was replaced by the Mac, a further version known as Object Pascal was created.

The Object Pascal extensions were added to Turbo Pascal with the release of version 5. Free Pascal is an open source, cross-platform alternative.

Important features included for this were records, enumerations, subranges, dynamically allocated variables with associated pointers, and sets. To make this possible and meaningful, Pascal has a strong typing on all objects, which means that one type of data cannot be converted or interpreted as another without explicit conversions.

Similar mechanisms are standard in many programming languages today. Pascal, like many programming languages of today but unlike most languages in the C familyallows nested procedure definitions to any level of depth, and also allows most kinds of definitions and declarations inside subroutines procedures and functions.

This enables a very simple and coherent syntax where a complete program is syntactically nearly identical to a single procedure or function except for the heading, which has one of these three keywords. The second attempt was implemented in a C-like language Scallop by Max Engeli and then translated by hand by R.

Schild to Pascal itself for boot-strapping. Many Pascal compilers since have been similarly self-hostingthat is, the compiler is itself written in Pascal, and the compiler is usually capable of recompiling itself when new features are added to the language, or when the compiler is to be ported to a new environment.

The target was the ICL series. It is thought that Multum Pascal, which was completed in the summer ofmay have been the first bit implementation. A completely new compiler was completed by Welsh et al.

It offered a source-language diagnostic feature incorporating profiling, tracing and type-aware formatted postmortem dumps that was implemented by Findlay and Watt at Glasgow University. Gillies for the PDP and generated native machine code.

The Pascal-P system[ edit ] To propagate the language rapidly, a compiler "porting kit" was created in Zurich that included a compiler that generated code for a "virtual" stack machine, i.

Pascal-P1 was the first version, and Pascal-P4 was the last to come from Zurich. The version termed Pascal-P1 was coined after the fact for the many different sources for Pascal-P that existed.

The compiler was redesigned to enhance portability, and issued as Pascal-P2. This code was later enhanced to become Pascal-P3, with an intermediate code backward compatible with Pascal-P2, and Pascal-P4, which was not backward compatible. However, it only accepts a subset of the Pascal language.

Turbo Pascal became hugely popular, thanks to an aggressive pricing strategy, having one of the first full-screen IDEs, and very fast turnaround time just seconds to compile, link, and run.

It was written and highly optimized entirely in assembly languagemaking it smaller and faster than much of the competition. These extensions were then added back into the PC version of Turbo Pascal for version 5.The P-system compilers were termed Pascal-P1, Pascal-P2, Pascal-P3, and Pascal-P4.

Pascal-P1 was the first version, and Pascal-P4 was the last to come from Zurich. The version termed Pascal-P1 was coined after the fact for the many different sources for Pascal-P that existed.

What is an IR? An intermediate representation is a representation of a program “between” the source and target languages. A good IR is one that is fairly independent of the source and target languages, so that it maximizes its ability to be used in a retargetable compiler.

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Early compilers were written in assembly language. The first self-hosting compiler -- capable of compiling its own source code in a high-level language -- was created for Lisp by Hart and Levin at MIT in In , Borland introduced Turbo Pascal, which sold for less than $, compiled an order of magnitude faster than existing compilers, and came with an abundance of source code and utility programs.

This product was a great success and was prominent for almost a decade. Early Pascal Compilers Harvard Case Study Solution and Analysis of Harvard Business Case Studies Solutions – Assignment HelpIn most courses studied at Harvard Business schools, students are provided with a case study.

Free Pascal is a 32, 64 and 16 bit professional Pascal compiler. It can target many processor architectures: Intel x86 (including ), AMD64/x, PowerPC, PowerPC64, SPARC, ARM, AArch64, MIPS and the JVM.

Compilers - Free Pascal wiki