A folding editor is a text editor

Text editor

A text editor is a type of program used for editing plain text files.Text editors are often provided with operating systems or software development packages, and can be used to change configuration files and programming language source code....

 which supports text folding or code folding

Code folding

Code folding is a feature of some text editors, source code editors and IDEs that allows the user to selectively hide and display sections of a currently-edited file as a part of routine edit operations...

, a mechanism allowing the user to hide and reveal blocks of text—usually named. Typically this is done to allow the user to better picture the overall structure of a document or program.

Folding is provided by many modern text editors, and syntax-based or semantics-based folding is now a component of many software development environments

Integrated development environment

An integrated development environment is a software application that provides comprehensive facilities to computer programmers for software development...

.

History

One of the earliest folding editors was STET

STET (text editor)

The STET text editor may have been the first folding editor; its first version was written in 1977 by Mike Cowlishaw. The editor runs on the IBM VM/CMS operating system....

, an editor written for the VM/CMS operating system in 1977 by Mike Cowlishaw

Mike Cowlishaw

Mike Cowlishaw is a retired IBM Fellow, a Visiting Professor at the Department of Computer Science at the University of Warwick, and is a Fellow of the Royal Academy of Engineering , the Institute of Engineering and Technology , and the British Computer Society.- Career at IBM :Cowlishaw joined IBM...

. STET is a text editor (for documentation, programs, etc.) which folds files on the basis of blocks of lines; any block of lines can be folded and replaced by a name line (which in turn can be part of a block which itself can then be folded).

A folding editor appeared in the occam IDE

Integrated development environment

An integrated development environment is a software application that provides comprehensive facilities to computer programmers for software development...

 circa 1983, which was called the Inmos Transputer Development System (TDS).. The "f" editor (in list below) probably is the most intact legacy from this work.

The Macintosh computer historically had a number of source code editor

Source code editor

A source code editor is a text editor program designed specifically for editing source code of computer programs by programmers. It may be a standalone application or it may be built into an integrated development environment ....

s that "folded" portions of code via "disclosure

Progressive disclosure

Progressive disclosure is an interaction design technique often used in human computer interaction to help maintain the focus of a user's attention by reducing clutter, confusion, and cognitive workload. This improves usability by presenting only the minimum data required for the task at hand...

 triangles". The UserLand Software

UserLand Software

UserLand Software is a US software company founded by Dave Winer in 1988. UserLand sells Web content management and blogging software packages and services.-Company History:Dave Winer founded the company in 1988 after leaving Symantec in the spring of 1988...

 product Frontier is a scripting environment that has this capability.

Editors with folding capability

A number of text editors provide folding capability. Those that do include:

External links

• What is a folding editor? by the author of the fe editor.
• Description of the folding editor used in occam.