Subtext programming language
Encyclopedia
Subtext is a moderately visual programming language
and environment, for writing application software
. It is an experimental, research attempt to develop a new programming model, called Example Centric Programming, by treating copied blocks as first class prototypes, for program structure. It uses live text, similar to what occurs in spreadsheet
s as users update cells, for frequent feedback. It is intended to eventually be developed enough to become a practical language for daily use. It is planned to be open software; the license is not yet determined.
Subtext was created by Jonathan Edwards who submitted a paper on the language to OOPSLA
. It was accepted as part of the 2005 conference.
Subtext programs are declared and manipulated (or mutated) by adding and linking elements of various types to a syntax tree, and entering in values or names as necessary, as opposed to typing out textual programs. Due to the design of the Subtext language and environment, there is no distinction between a program's representation and its execution. Like spreadsheets, Subtext programs are live executions within an environment and runtime, and programming is direct manipulation of these executions via a graphical environment
. Unlike typical functional programming
languages, Subtext has simple semantics and is easily applicable to reactive systems that require mutable state, I/O, and concurrency, under a model known as "Reactive Programming". Console
input ("invocations") can be utilized via data flow within a Subtext program, allowing users to manipulate values interactively.
State changes trigger events called reactions, that in turn change other states. A coherent execution order is one in which each reaction executes before any others that are affected by its changes. A coherent order is discovered iteratively by detecting incoherencies as they occur and backtracking their effects. The fundamental building block of Coherence is the dynamically typed mutable tree. The fundamental abstraction mechanism is the virtual tree, whose value is lazily computed, and whose behavior is generated by coherent reactions.
Related
Visual programming language
In computing, a visual programming language is any programming language that lets users create programs by manipulating program elements graphically rather than by specifying them textually. A VPL allows programming with visual expressions, spatial arrangements of text and graphic symbols, used...
and environment, for writing application software
Application software
Application software, also known as an application or an "app", is computer software designed to help the user to perform specific tasks. Examples include enterprise software, accounting software, office suites, graphics software and media players. Many application programs deal principally with...
. It is an experimental, research attempt to develop a new programming model, called Example Centric Programming, by treating copied blocks as first class prototypes, for program structure. It uses live text, similar to what occurs in spreadsheet
Spreadsheet
A spreadsheet is a computer application that simulates a paper accounting worksheet. It displays multiple cells usually in a two-dimensional matrix or grid consisting of rows and columns. Each cell contains alphanumeric text, numeric values or formulas...
s as users update cells, for frequent feedback. It is intended to eventually be developed enough to become a practical language for daily use. It is planned to be open software; the license is not yet determined.
Subtext was created by Jonathan Edwards who submitted a paper on the language to OOPSLA
OOPSLA
OOPSLA is an annual ACM research conference. OOPSLA mainly takes place in the United States, while the sister conference of OOPSLA, ECOOP, is typically held in Europe...
. It was accepted as part of the 2005 conference.
Environment
Early video previews of the Subtext environment were released circa 2006, which demonstrated the semantics of Subtext programs, and the close integration with the Subtex environment and runtime.Subtext programs are declared and manipulated (or mutated) by adding and linking elements of various types to a syntax tree, and entering in values or names as necessary, as opposed to typing out textual programs. Due to the design of the Subtext language and environment, there is no distinction between a program's representation and its execution. Like spreadsheets, Subtext programs are live executions within an environment and runtime, and programming is direct manipulation of these executions via a graphical environment
Graphical user interface
In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...
. Unlike typical functional programming
Functional programming
In computer science, functional programming is a programming paradigm that treats computation as the evaluation of mathematical functions and avoids state and mutable data. It emphasizes the application of functions, in contrast to the imperative programming style, which emphasizes changes in state...
languages, Subtext has simple semantics and is easily applicable to reactive systems that require mutable state, I/O, and concurrency, under a model known as "Reactive Programming". Console
Console
- Computing and video games :* System console, a physical device to operate a computer** Virtual console, a user interface for multiple computer consoles on one device** Command-line interface, the typical use of the computer console...
input ("invocations") can be utilized via data flow within a Subtext program, allowing users to manipulate values interactively.
Coherence
A continuation and subset of the Subtext language using other principles, is Coherence, an experimental programming language and environment, which uses a new model of change-driven computation called "Coherent reaction", to coordinate the effects and side-effects of programs interactively as they are being developed. The language is specialized for interactive application software, and is being designed by the creator of Subtext, Jonathan Edwards, who reports upon its development by publishing white papers.State changes trigger events called reactions, that in turn change other states. A coherent execution order is one in which each reaction executes before any others that are affected by its changes. A coherent order is discovered iteratively by detecting incoherencies as they occur and backtracking their effects. The fundamental building block of Coherence is the dynamically typed mutable tree. The fundamental abstraction mechanism is the virtual tree, whose value is lazily computed, and whose behavior is generated by coherent reactions.
External links
Official- Subtextual.org, official website of Subtext.
- Coherence, official website of Coherence.
- Alarming Development, Weblog for Subtext discussion and debate.
Related
- James Shore: I Want Subtext, the benefits of Subtext and improvements to the schematic tables for abstractionAbstraction (computer science)In computer science, abstraction is the process by which data and programs are defined with a representation similar to its pictorial meaning as rooted in the more complex realm of human life and language with their higher need of summarization and categorization , while hiding away the...
. - Subtext Info Page, Email list with archives, means to subscribe/unsubscribe.