Difference between revisions of "FAQ"

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== 1.  What is the purpose of Clean? ==
 
== 1.  What is the purpose of Clean? ==
  
The purpose of Clean is to serve as a non-strict, purely functional programming language with the following advantages over similar functional programming languages:
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The purpose of Clean is to serve as a fast, non-strict, purely functional programming language that is easy to optimize.  Clean is characterized by lazy evaluation, which means that only arguments that need to be evaluated in a function call are actually evaluated.  In addition, Clean functions can be written to use (partially) strict evaluation when necessary.  Unlike R6RS Scheme and similar to Haskell, Clean offers pattern-matching, guards, array comprehensions, and a Hindley-Milner style type inferencing scheme .  Unlike Haskell, Clean offers list comprehensions.  For I/O-related functions, in contrast to Haskell's monads, Clean offers a uniqueness type inferencing system, which allows destructive transformation of state information within a purely functional framework.  Clean is useful for writing relatively bug-free programs in fewer lines of code, and for formally proving properties of those programs, thereby often eliminating the need for debugging.
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== 2.  What are the advantages of Clean? ==
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Clean has the following advantages over similar functional programming languages:
 
*'''Efficient running-time of compiled code:'''  Clean is one of the fastest functional programming languages.  For many applications, Clean is appreciably faster than Haskell, and at least on par with OCaml.  According to a [http://shootout.alioth.debian.org/gp4/benchmark.php?test=all&lang=clean&lang2=ghc Gentoo benchmark], the current Clean entry runs the [http://shootout.alioth.debian.org/gp4/benchmark.php?test=meteor&lang=all meteor-contest] benchmark 2.6 times faster than the corresponding Haskell GHC entry.
 
*'''Efficient running-time of compiled code:'''  Clean is one of the fastest functional programming languages.  For many applications, Clean is appreciably faster than Haskell, and at least on par with OCaml.  According to a [http://shootout.alioth.debian.org/gp4/benchmark.php?test=all&lang=clean&lang2=ghc Gentoo benchmark], the current Clean entry runs the [http://shootout.alioth.debian.org/gp4/benchmark.php?test=meteor&lang=all meteor-contest] benchmark 2.6 times faster than the corresponding Haskell GHC entry.
 
**For benchmarks, see the following:
 
**For benchmarks, see the following:

Revision as of 13:23, 29 February 2008

1. What is the purpose of Clean?

The purpose of Clean is to serve as a fast, non-strict, purely functional programming language that is easy to optimize. Clean is characterized by lazy evaluation, which means that only arguments that need to be evaluated in a function call are actually evaluated. In addition, Clean functions can be written to use (partially) strict evaluation when necessary. Unlike R6RS Scheme and similar to Haskell, Clean offers pattern-matching, guards, array comprehensions, and a Hindley-Milner style type inferencing scheme . Unlike Haskell, Clean offers list comprehensions. For I/O-related functions, in contrast to Haskell's monads, Clean offers a uniqueness type inferencing system, which allows destructive transformation of state information within a purely functional framework. Clean is useful for writing relatively bug-free programs in fewer lines of code, and for formally proving properties of those programs, thereby often eliminating the need for debugging.

2. What are the advantages of Clean?

Clean has the following advantages over similar functional programming languages: