PLT Scheme is an umbrella name for a family of Scheme implementations:
- DrScheme is the primary PLT Scheme implementation. Scheme is a Multi-paradigm programming language. It is one of the two main dialects of Lisp and supports a number of programming paradigms but is DrScheme is an Open source Integrated development environment for the Scheme programming language which has a Graphical user interface.
- MzScheme is the lightweight, embeddable, scripting-friendly PLT Scheme implementation.
- TeachScheme! is a PLT project to turn Computing and Programming into an indispensable part of the liberal arts curriculum. The TeachScheme! project is an outreach effort of the PLT research group
- PLaneT[1] is PLT's centralized package distribution system. Visit for a list of user-contributed packages.
"PLT" is the group of people who produce PLT Scheme.
Contents |
History
Matthias Felleisen founded PLT in the mid 1990s, first as a research group, soon after as a project dedicated to the production of pedagogic materials for novice programmers (lectures, exercises/projects, software). Matthias Felleisen is a Computer science professor and an author of German background In January 1995, the group decided to develop a pedagogic programming environment. Matthew Flatt cobbled together MrEd (a pun and a tease) from libscheme, wxWindows, and a number of other free systems. Over the year, Robby Findler, Shriram Krishnamurthi, Cormac Flanagan, and some others produced DrScheme, a programming environment for novice Scheme programmers and a research environment for soft typing. DrScheme is an Open source Integrated development environment for the Scheme programming language which has a Graphical user interface.
In parallel, the team started conducting workshops for high school teachers, training them in program design and functional programming. Field tests with these teachers and their students provided essential clues for the direction of the development.
Over the following years, PLT added teaching languages, an algebraic stepper, a transparent read-evaluate print loop, a constructor-based printer, and many other innovations to DrScheme. Due to these, DrScheme is an application quality pedagogic program development environment. By 2001, the core team (Robert Bruce Findler, Matthew Flatt, Shriram Krishnamurthi) had also written and published their first text book, How to Design Programs, on their teaching philosophy. Robert Bruce Findler, colloquially known as "Robby" is a computer scientist currently teaching at the University of Chicago. Matthew Flatt is a computer scientist currently teaching at the University of Utah (Salt Lake City How to Design Programs (HtDP is a textbook by Matthias Felleisen, Robert Bruce Findler, Matthew Flatt and Shriram Krishnamurthi
Today, DrScheme is far more than a pedagogic programming environment. It supports module-oriented programming with a module browser, a contour view, integrated testing and coverage measurements, syntax-level refactoring, and many more tools. The team uses DrScheme to develop DrScheme, and developers around the world use it to produce commercial software.
Research
From the beginning, the PLT project was also an experiment in evaluating the suitability of Scheme as a programming language for large projects. Scheme is a Multi-paradigm programming language. It is one of the two main dialects of Lisp and supports a number of programming paradigms but is In a sense, the language failed and yet it also proved to be an ideal platform.
Scheme per se failed because the standard language, as defined in the reports, is too small for a team of 20-30 developers, distributed across three continents. If taken as an ideal kernel, however, Scheme succeeded beyond the team's expectations. It proved easy to extend the language with
- the first mixin class system;
- a component (or module) system, as sophisticated and expressive as Standard ML's;
- a powerful macro system for meta-programming
- the first practical system of delimited control
- and many more constructs that heavily influence the next-generation Scheme report. Standard ML ( SML) is a general-purpose modular, Functional programming language with Compile-time type checking and Type inference
The most remarkable feature of these remains the macro system. It provides far more expressive power than Lisp's S-expression manipulation system, Scheme 84's hygienic extend-syntax macros, or R5RS's syntax rules. Indeed, it is fair to say that the macro system is a carefully tuned API for the compiler. Using this compiler API, programmers can add features and entire domain-specific languages in a manner that makes them completely indistinguishable from built-in language constructs. For example, both the class system and the component system are nothing but macro libraries.
In addition to research on programming languages, PLT also used its infrastructure to investigate programming patterns, interactive web programming, refactoring, and many more topics.
Scripting
Over the years, PLT and PLT Scheme programmers have also turned the language into a scripting tool. PLT Scheme is now a viable alternative for
- scripting the Unix shell;
- web servers;
- slide show presentations;
- psychology experimentation software;
- and some others.
PLT Scheme now includes libraries like all common scripting languages. For the last three years, PLT has also maintained PLaneT, a web-based module repository that is smoothly integrated with its module/library system.
References
- Felleisen et al. The TeachScheme! Project. Journal of Computer Science Education. 2004. [2]
- Findler et al. DrScheme: A Programming Environment for Scheme. Journal of Functional Programming. 2001. [3]
- Flatt et al. Programming Languages as Operating Systems. International Conference on Functional Programming. 1999. [4]
- Jacob Matthews. You want it where? Component Development with PLT Scheme. Workshop on Scheme and Functional Programming, 2006. [5]
External links
Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic