WWW Survey Page of Language "Icon"

LANGUAGE NAME: Icon

CATEGORY: Object-Oriented Language

ORIGIN: SNOBOL4

YEAR: 1978

ORIGINATOR: Ralph E. Griswold and Gregg M. Townsend at the University of Arizona

HISTORY:

• Icon is a succesor to SNOBOL4:
  The first SNOBOL language was developed in 1962. A succession of improvements
  led to SNOBOL4 in 1968. Few changes have been made to SNOBOL4 since then.
  Further language development led to Icon in 1978. Icon has evolved through a series
  of versions, the latest of which was released in 1993.

BASIC FEATURES:

• very high level general-purpose programming language with extensive features for
  processing strings(text) and data structures
  - built-in data types include numerics, character sets, string, sets, list, associative
  tables, records, and procedures
  - aggregate types(sets, lists, tables, and records) can hold values of any type, and
  use pointer semantics
• imperative, procedural language with a syntax that is resembing C and Pascal,
  but its semantics are at a much higher level than those languages
• strongly, though not statically, typed language
  - values, not variables, are typed
• best when used as a prototyping tool for processing text, and when ease of
  programming is needed for experimental and research applications.

ADVANCED FEATURES:

• support for strings of characters of arbitrary length
  - stings and aggregates can be of arbitrary size, and their size can be change during
  execution.
• high-level facilities for analyzing strings
  - string scanning allows operations on strings to be formaulated at a high conceptional
  level.
• a powerful expression-evaluation mechanism
  - expressions produce sequences of results, goal-directed evaluation that automatically
  searches for a successful result.
• sophisticated data structures for managing complex relationships among data
• high-level graphics facilities
• automatic storage management
  - memory management is automatic.

INTERESTING ADDITIONAL FEATURES:

• designed to make programming easy but, paradoxically, Icon is used most often
  for short, one-shot tasks and for very complex applications.
• Although Icon has extensive facilities for processing strings and structures, it also has
  full computational facilities which are suitable for a wide variety of applications such as
  - text analysis
  - text editing
  - document formatting
  - artificial intelligence
  - expert systems
  - rapid prototyping
  - symbolic mathmatics
  - text generation
  - data laundry.

RELATED WWW SITES:

• Click here to link to home page of icon-project at the University of Arizona
• Click here to use a tutorial for the Icon programming language
• Click here to use the official Icon FAQ

SOFTWARE ARCHIVE SITES:

• Icon is available via anonymous FTP.
  Use ftp.cs.arizona.edu and cd /icon.

NEWSGROUP:

• Click here to link to a newsgroup - comp.lang.icon - for discussing issues
  related to Icon.
• The Icon Project at the University of Arizona maintains an electronic mailing list, icon-group@cs.arizona.edu.
  To subscribe, send a message to icon-group-request@cs.arizona.edu.