newLISP

newLISP

File:Nl logo libel side color 240X100.png
Paradigm	Multi-paradigm
Appeared in	1991
Designed by	Lutz Mueller
Developer	Lutz Mueller of Nuevatec
Stable release	10.1.7 (November 24, 2009)
OS	Cross-platform
License	GNU General Public License
Website	www.newlisp.org

newLISP is an open source scripting language in the Lisp family of programming languages developed by Lutz Mueller and released under the GNU General Public License.

History

newLISP has its origin back in 1991 and was originally developed on a Sun-4 workstation, then moved to Windows 3.0, where version 1.3 was released on CompuServe around 1993. newLISP was then available as a Windows GUI graphics capable application and a DOS console application (both 16bit). In 1995, with the release of Windows 95, newLISP moved to 32-bit.

In April 1999, newLISP was ported to Linux, some of the core algorithms were rewritten, and all Windows-specific code eliminated. In 1999, newLISP was released as an Open Source project, licensed under the GPL, and development stopped on Windows after version 6.0.25. During the first half of 2001 newLISP was ported back to Windows again on to the Cygwin platform and without graphics capabilities. A multi-platform Tcl/Tk frontend named newLISP-tk was released around version 6.3.0, during the second half of 2001. 64-bit precision was introduced for integer arithmetic and for some operations on files in version 9.0 in 2006.

Since the release of 6.5 in mid 2002, development has been very active: many new features have been added, and a community of users has grown.

Philosophy

The aim of newLISP is to provide a fast, powerful, cross-platform, full-featured scripting version of the Lisp programming language which uses only a modest amount of system resources such as disk space and memory.

newLISP runs on the BSDs, Linux, Windows, Mac OS X, and Solaris operating systems.

newLISP provides essential Lisp features such as lists, functions, symbol processing, recursion, function mapping, anonymous functions (lambda expressions), s-expressions (excluding improper lists), and macros.

newLISP also provides all the functions expected of a modern scripting language, including support for regular expressions, XML, Unicode (UTF-8), TCP/IP and UDP networking, matrix and array processing, advanced math, statistics and Bayesian statistical analysis, financial mathematics, and distributed computing support.

The newLISP installation provides support for MYSQL, SQLite and ODBC database access, CGI, SMTP, POP3, FTP and XML-RPC. Newlisp can also run as a daemon (server mode).

newLISP aims for conservative memory requirements: on Linux a Newlisp process uses about 600KB of memory. The binary executable file occupies about 200KB of disk space on Linux.

With this combination of extensive built-in libraries and its modest use of resources, newLISP is suitable for quick prototyping, system customization, server-side CGI scripting, and for use as an embedded scripting language.

The language aims to provide a simple, consistent, streamlined, Lisp environment that minimizes the learning curve and maximizes programmer productivity and pleasure.

For more information, refer to the newLISP FAQ and the newLISP documentation referenced below.

The language

Contexts

newLISP supports namespaces called contexts. They can be assigned to variables and passed to functions, but they are associated with globally unique symbols, which limits their usage as first-class objects. A prototype-based OO style of programming is possible in newLISP, using contexts as prototypes for construction of objects. Variables inside contexts do not interfere with variables of the same name in other contexts, but inside a context variables behave according to the rules of dynamic scoping.

Scoping

newLISP uses dynamic scoping. This means, when a function is called, it can see all variables of its caller and its caller's caller, and so on, within the same context or name space. newLISP supports explicitly and implicitly defined local dynamic variables that shadow variables with the same name from the outer environment, so accidental use or change of the variables from caller environment is prevented. Parameter variables of the called function automatically shadow (overwrite) the callers variable environment. Globally, variables can be grouped in separate namespaces, named "context."

Memory management

newLISP uses a method of automatic memory management different from traditional garbage collection schemes called One Reference Only (ORO) Memory Management.

Each variable is referenced only by its context, and each context is referenced globally.

newLISP does not support sharing of sub-objects among objects, cyclic structures, nor multiple variables pointing to the same object. Objects are (physically) copied when stored in data structures or passed to functions, except passing to particular built in functions. The exceptions are symbols and contexts, which are not implicitly copied but shared, and thus they can be used for indirection. Symbols and contexts are globally named and are deleted explicitly; deleting a symbol or context scans all other objects to replace references to it with nil.

GUI options

newLISP-GS (Gui Server) is a Java based TCP/IP server providing a graphical programming interface. Although a newLISP-GS based development environment is distributed as a default with newLISP binary distributions, GTK-server, OpenGL and Tcl/Tk based programming interfaces are available too.

Stand-alone binaries

It is possible to construct executable files for deployment using any version of newLISP . These files are self-contained and require no installation.

Interaction with shared libraries

newLISP has an import function, which allows importing function from DLLs (Dynamic Link Libraries) on Win32 or shared libraries on Linux/UNIX.

External links

• newLISP Home Page
• newLISP Documentation
• newLISP Code Patterns WIKI
• Automatic Memory Management in newLISP
• Differences to other LISPs
• Dragonfly - a newLISP web framework