Documentation: Difference between revisions

* Related task: [[Here_document]]

<br><br>

=={{header|Ada}}==

In some ways, Ada is a self documenting language by design. When building packages (the equivalent of modules in python), you have to create two separate files: a spec and a body. The spec resides in a .ads file, and contains the interface to the package that is visible to someone using it.

 

Example ADS file for instrumenting sorting functions:

 

generic

procedure Put (File : in out File_Type);

 

There is also a tool called [http://sourceforge.net/projects/adadoc/ AdaDoc]. This can be used to generate documentation of an Ada module (or modules?) for a variety of different formats: HTML, LaTeX, plain text and more.

 

=={{header|AutoHotkey}}==

It generates html documentation in the style of the canonical ahk [http://www.autohotkey.com/docs/commands/MsgBox.htm documentation]. <br>

[http://en.wikipedia.org/wiki/BBCode BBCode] is supported for markup. <br>

; Function: example_add

; Description:

example_add(number1, number2, number3=0){

return number1 + number2 + number3

 

=={{header|C}}==

A common tool for generating documentation is [http://www.stack.nl/~dimitri/doxygen/ Doxygen]:

* \brief Perform addition on \p a and \p b.

*

return a + b;

}

 

=={{header|C sharp|C#}}==

This documentation method will work perfectly with the built in object browser in Visual Studio. The object browser can then show detailed information for each component. To make documentation that can be parsed, a triple slash (///) must be used. Further information can be found in [http://aspalliance.com/696 this tutorial]. A list of available xml elements for use in documentation [http://aspalliance.com/696_Code_Documentation_in_NET.2 is here].

 

/// The XMLSystem class is here to help handle XML items in this site.

/// </summary>

return null;

}

 

=={{header|Clojure}}==

#^{:doc "Metadata can contain documentation and can be added to vars like this."}

test1)

(defn test2

"defn and some other macros allow you add documentation like this. Works the same way"

 

=={{header|COBOL}}==

the HTML generation process.

 

*>****L* cobweb/cobweb-gtk [0.2]

*> Author:

end program cobweb-gtk.

*>****

 

{{works with|GnuCOBOL}}

markup processors, like Sphinx ReStructureText or Markdown.

 

>>IF docpass NOT DEFINED

 

ReStructuredText or other markup source ...

>>END-IF

 

Extraction of documentation segments is feasible using just the Compiler

CL-USER 88 > (documentation 'person 'type)

"the person class"

 

=={{header|D}}==

D compiler comes with a builtin documentation system called [http://digitalmars.com/d/1.0/ddoc.html Ddoc]. Alternative systems may be used (a common alternative is [http://www.stack.nl/~dimitri/doxygen/ Doxygen] which includes some D support).

This is a documentation comment for someFunc and someFunc2.

$(DDOC_COMMENT comment inside a documentation comment

 

/++ Another documentation comment +/

 

=={{header|Delphi}}==

XML comments are shown in the IDE and is included in the XML documentation produced by the compiler when using --docs.

/// <summary>Sample class.</summary>

TMyClass = class

/// <exception cref="EConvertError">aValue is not a valid integer.</exception>

function StringToNumber(aValue: string): Integer;

 

=={{header|E}}==

The documentation syntax is in some ways underdefined: there is no layer which discards the leading '*'s as in Javadoc, so the documentation string contains all leading indentation (which is problematic for the source prettyprinter), and there is no formal definition yet of the syntax used within the doc-comments.

 

> def foo {

> # ...

 

? foo.__getAllegedType().getDocComment()

 

Variables may not have doc-comments, because they are never part of the public interface of an object.

The following is a simple class written in Eiffel:

 

description: "Objects that model Times of Day: 00:00:00 - 23:59:59"

author: "Eiffel Software Construction Students"

second_valid: 0 <= second and second <= 59

 

 

Below is the '''Contract''' (documentation) view of the same class. It is the view that potential reuse consumers would reference when writing clients.

 

description: "Objects that model Times of Day: 00:00:00 - 23:59:59"

author: "Eiffel Software Construction Students"

second_valid: 0 <= second and second <= 59

 

 

It is important to notice what is missing from this view. It shows only the specification of the class. The implementations of routines and any routines which are not public are not visible. The notes and comments, public features (including contracts for routines), and the class invariant all remain as components of the specification.

=={{header|Elixir}}==

Elixir uses [https://github.com/elixir-lang/ex_doc ExDoc] in order to document code. ExDoc allows users to pull data (such as name, version, source link) into their app. For example (taken from the ExDoc documentation):

def project do

[app: :repo

deps: deps]

end

 

Individual modules can be documented using the @moduledoc attribute and heredocs (with markdown):

defmodule MyModule do

@moduledoc """

"""

end

 

=={{header|Emacs Lisp}}==

In <code>defun</code>, <code>defmacro</code> and <code>defsubst</code> an optional docstring can follow the formal parameters.

 

"Say hello to the user."

 

For <code>defvar</code>, <code>defconst</code> or <code>defcustom</code> an optional docstring follows the value.

 

 

Most other defining forms have similar optional docstrings. In all cases they must be a string constant.

 

=={{header|Fancy}}==

"""

This is a docstring. Every object in Fancy can have it's own docstring.

}

Foo docstring println # prints docstring Foo class

 

=={{header|Forth}}==

example :

 

 

Another good practice is describing the stack use of a function : function ( stack before -- stack at end )

example :

 

 

=={{header|Fortran}}==

Outside systems are available to assist. It is common for text editors to employ syntax highlighting, but their designers rarely handle the full complexity of Fortran syntax correctly. For instance, the format of a number such as -3.145E+07 is difficult to scan, especially since in Fortran source, spaces are ignored outside of text literals. Then, consider the FORMAT codes, such as <code>31E16.7</code> and similar sequences. More serious efforts scan the Fortran source in order to extract information useful for documentation. There have long been available systems that will identify every routine in a programme and for each identify what routine calls it, and what routines it calls, along with further analysis on their parameters and their usage - this well before F90 introduced the optional INTENT feature. Similarly, within each routine, identify which variables are used (possibly as parameters) where and whether they are read or written there. And, analyse the usage of COMMON variables... Likewise, documentation might include a flowchart, and systems exist to produce these as well.

 

REAL*8 A !Distance to the next node.

Quite useful documentation could be extracted just from that. By mixing actual source statements with the commentary and extracting ''both'', inane clashes can be reduced, as in <code>CHARACTER*6 TLA !Three-character name.</code> that arose because a modification to the nature of the parameter had been made, but, while revising every routine that employed such a parameter, the programmer's consciousness faded out as soon as it saw the comment start and noted "non-Fortran source", to the puzzlement of subsequent readers. A system that extracted only the commentary part from that would not give a correct report, whereas with it known that the actual declaration would be included, there would be no longer any need to repeat its details in the comment and the comment could confine itself to expounding on meaning and usage. On the other hand, F90 introduced a verbose scheme for declarations wherein something like <code>SELECTED_REAL_KIND(6, 70)</code> might appear and copying that may well merely copy obfuscation.

 

 

Example code demonstrating what godoc extracts and what it doesn't:

//

// A package comment preceeds the package clause and explains the purpose

// Doc not extracted.

 

Text output of godoc: (HTML looks nicer, of course)

<pre>

New commands can have optional help text between the command name line and the opening <code>{</code> brace.

 

Print a greeting to the user.

This is only a short greeting.

{

show "hello"

 

Any literal braces in the text must be backslash escaped <code>\{</code>. The text is shown by the online help system, similar to builtin commands.

 

 

(See section "Simple New Command" in the GRI manual.)

[http://haskell.org/haddock/ Haddock] is a popular documentation generator for the Haskell language.

 

square1 :: Int -> Int

square1 x = x * x

-- |This is a documentation comment for the following type class

class Foo a where

 

See [http://haskell.org/haddock/doc/html/markup.html this chapter] for more information about the markup.

==={{header|Icon}}===

There are no formal conventions for documentation built into the Icon/Unicon. However, there are conventions for the different libraries that are supported by automation.

#

# File: filename.icn

 

procedure x1() #: short description of procedure

 

{{libheader|Icon Programming Library}}

 

=={{header|Isabelle}}==

imports Main

begin

text ‹This text will only compile if the constant \<^const>‹True› is defined.›

 

 

 

==={{header|Unicon}}===

{{improve|Unicon|Needs corresponding Unilib formats}}

 

=={{header|J}}==

Use [http://www.jsoftware.com/trac/base/browser/trunk/main/script/doc.ijs?rev=1 scripdoc]:

NB.*apply v apply verb x to y

apply=: 128!:2

usleep

3 : '''libc.so.6 usleep > i i''&(15!:0) >.y'

 

=={{header|Java}}==

Documentation is typically given using [http://www.j2ee.me/j2se/javadoc/index.jsp Javadoc] comments. Documentation is generated from these comments using the Javadoc tool. The default output (from the standard doclet) takes the form of an [[HTML]] page with frames, so HTML is frequently embedded in the comments. The comments all start with <code>/**</code>, end with <code>*/</code>, and usually have "tags" embedded starting with <code>@</code>.

* This is a class documentation comment. This text shows at the top of the page for this class

* @author Joe Schmoe

//...code here

}

 

=={{header|Julia}}==

Any string appearing at the top-level right before an object (function, macro, type or instance) will be interpreted as documenting it (these are called docstrings). Note that no blank lines or comments may intervene between a docstring and the documented object. Here is a basic example:

 

"Tell whether there are too foo items in the array."

foo(xs::Array) = ...

 

Documentation is interpreted as Markdown, so you can use indentation and code fences to delimit code examples from text. Technically, any object can be associated with any other as metadata; Markdown happens to be the default, but one can construct other string macros and pass them to the @doc macro just as well.

Here is a more complex example, still using Markdown:

 

"""

bar(x[, y])

"""

function bar(x, y) ...

 

=={{header|Kotlin}}==

 

The following is a slightly extended version of the example in the official Kotlin documentation:

* A group of *members*.

* @author A Programmer.

*/

fun add(member: T): Int { ... }

 

=={{header|Lambdatalk}}==

 

Lambdatalk works in a small wiki, lambdatank, where can be written easily (as in a standard text editor) any informations about the keywords, the set of primitives, and the eventual user defined functions and libraries. For instance this is how a function is built, displayed and tested in the browser's window:

'{def add // define the name

{lambda {:a :b} // for a function with two arguments

'{add 3 4} // call the function on two values

-> 7 // the result

 

=={{header|Logtalk}}==

Logtalk provides a set of entity and predicate documenting directives. The content of these and other directives can be retrieved using the language reflection features. A companion tool, "lgtdoc", uses the reflection API to extract the documenting information and export it as XML files and provides a set of stylesheets to convert these file to e.g. HTML and PDF files.

 

:- object(set(_Type),

extends(set)).

 

:- end_object.

 

=={{header|Lua}}==

Requires an external tool, the most widely-used of which (at present) is [https://github.com/lunarmodules/LDoc LDoc].

-- Given an angle measure in degrees, return an equivalent angle measure in radians (long description).

-- @param deg the angle measure in degrees

-- @return the angle measure in radians

-- @see rad2deg

 

=={{header|Mathematica}} / {{header|Wolfram Language}}==

Mathematica inline documentation can be accessed directly in the code by pressing F1. No external tools required

f::usage = "f[x,y] gives the sum of x and y"

 

?f

 

=={{header|MATLAB}} / {{header|Octave}}==

% My first MatLab attempt, to swallow data as produced by Gnash's DUMP

The comments will be revealed. However, a test with Octave elicited only the comment on the "function" line. If the file contained merely a sequence of commands (i.e. did not constitute the definition of a function) the first line of the above example would be absent and the file would start with a comment block.

 

=={{header|Neko}}==

 

 

The feature does not care what file type is used for input, and most C sources for Neko libraries include documentation blocks of this type.

 

result_set_conv_date : 'result -> function:1 -> void

<doc>Set the function that will convert a Date or DateTime string

to the corresponding value.</doc>

 

=={{header|Nim}}==

## hashes (##). To create the documentation run ``nim doc file.nim``.

## ``nim doc2 file.nim`` is the same, but run after semantic checking, which

## A useful procedure

for i in 1..times:

 

=={{header|Objeck}}==

Documentation can be produced for bundles, classes and methods/functions.

 

Sets the named row value

@param name name

return Set(@table->GetRowId(name), value);

}

 

=={{header|Objective-C}}==

 

===HeaderDoc===

@function add

@abstract Adds two numbers

int add(int a, int b) {

return a + b;

 

=={{header|OCaml}}==

[http://caml.inria.fr/pub/docs/manual-ocaml/manual029.html OCamldoc] is a documentation generator that is included with OCaml. Documentation comments all start with <code>(**</code> (but no more than two asterisks) and end with <code>*)</code>. Like Javadoc, "tags" can be embedded starting with <code>@</code>.

 

=={{header|PARI/GP}}==

The primary method for documenting GP functions is the <code>addhelp()</code> command:

PARI documentation is done as for [[#C|C]].

 

from the project tree of the last run/file being edited. Pressing F1 again cycles through them.<br>

Ideally any routine-specific comments should be placed within the routine itself, eg (from pmain.e):

Note: As I understand it, tools such as Doxygen usually expect their markup to precede the actual definitions.

 

=={{header|PicoLisp}}==

PicoLisp doesn't yet support inline documentation directly in the code. However, it has built-in runtime documentation via the '[http://software-lab.de/doc/refD.html#doc doc]' function. This requires no external tools, except that the interpreter must have been started in debug mode.

 

: (doc '+Entity) # View documentation of a class

 

 

=={{header|PL/I}}==

=={{header|PowerShell}}==

PowerShell includes complete built-in help for comment-based help: Just run help about_comment_based_help.

help about_comment_based_help

 

=={{header|PureBasic}}==

; documentation system.

 

CloseFile(file)

EndIf

This would as an example be shown in the code over view as the picture below.

 

A string literal which is the first expression in a class, function, or module definition is called a [http://docs.python.org/glossary.html#term-docstring docstring]. It can be subsequently accessed at runtime using the <code>.__doc__</code> attribute of the class, function, or module.

 

"""

This is a class docstring. Traditionally triple-quoted strings are used because

def method(self, num):

"""This is a method docstring."""

 

'''[http://docs.python.org/library/pydoc.html pydoc]''', a module of the Python standard library, can automatically generate documentation gleaned from docstrings of modules. The documentation can be presented as pages of text on a terminal; automatically served to a Web Browser; or saved as HTML. The command line pydoc command , in addition, can display docstring information in a TK based GUI browser.

 

The built-in help() function uses the pydoc module to display docstring information at the command prompt of the Python interactive shell.

"takes no args and returns None after doing not a lot"

 

takes no args and returns None after doing not a lot

 

 

===Sphinx===

=={{header|R}}==

R objects are documented in files written in "R documentation" (Rd) format, which is similar to LaTeX markup. See Chapter 2 of [http://cran.r-project.org/doc/manuals/R-exts.pdf Writing R Extensions] for the full details. Example function document files can be created using

An example documentation file for a function 'f', taking arguments 'x' and 'y' is

\Rdversion{1.1}

\alias{f}

% R documentation directory.

\keyword{ ~kwd1 }

 

=={{header|Racket}}==

domain-specific language called Scribble:

 

#lang scribble/manual

(require (for-label "sandwiches.rkt"))

Returns a sandwich given the right ingredients.

}

 

Programs can also be written with inline documentation using either the

Similarly to Perl 5, Raku is documented using [https://docs.raku.org/language/pod Pod] (a redesigned version of POD). However, it's not simply ignored by the parser as in Perl 5, it's an internal part of the language spec and can be used to attach documentation objects to almost any part of the code.

 

#= it's yellow

sub marine { ... }

}

say Sheep.WHY; # "a shaggy little thing"

 

A compiler has a built-in <code>--doc</code> switch that will generate documentation from a given source file. An output format can be specified in the switch. For example, <code>--doc=Markdown</code> will generate Markdown from Pod provided that the <code>Pod::To::Markdown</code> is installed.

 

=={{header|REBOL}}==

Title: "Documentation"

URL: http://rosettacode.org/wiki/Documentation

x: get in bob 'hi help x print ""

 

 

Output:

Retro uses a literate source format called Unu. Sources are typically using a subset of Markdown.

 

# Determine The Average Word Name Length

 

'Average_name_length:_%n\n s:format s:put

~~~

 

This illustrates the format. Only code in the fenced blocks (between \[[User:Crc|Crc]] ([[User talk:Crc|talk]]) pairs) get extracted and run.

 

<br>Note that the documentation is bracketed by the standard REXX comment delimiters to preserve program lexicographical integrity.

parse arg doc /*obtain (all) the arguments from C.L. */

if doc='?' then call help /*show documentation if arg=a single ? */

If no "numberOfItems" are entered, the default of 100 is used.

</help>

 

===version 2===

* 13.10.2013 Walter Pachl another way to show documentation

* no tags and good enough if only one documentation block

say 'the program would be here!'

Exit

 

=={{header|Ring}}==

/*

Multiply two numbers

func mult n1, n2

return n1*n2

 

=={{header|Ruby}}==

 

Ruby's documentation comments look like Perl's PODs. Translating Java's example:

RDoc is documented here[http://www.ruby-doc.org/core/classes/RDoc.html].

 

end

 

 

=={{header|Rust}}==

 

Here's an example of some heavily documented mock code:

//!

//! **Lorem ipsum** dolor sit amet, consectetur adipiscing elit. Aenean a

let foo = Whatchamabob{ doodad: 1.2, thingamabob: false };

foo.frob();

 

=={{header|Scala}}==

Excellent documentation about ScalaDoc is given [https://docs.scala-lang.org/style/scaladoc.html here in the Scala Style Guide.]

* This is a class documentation comment. This text shows at the top of the page for this class

*

???

}

 

=={{header|Smalltalk}}==

In addition, all support class comments as follows:

(Squeak/Pharo/VisualWorks/SmalltalkX)

 

=={{header|SQL PL}}==

{{works with|Db2 LUW}}

{{libheader|db2doc}}

CREATE TABLESPACE myTs;

 

 

COMMENT ON ROLE mySeq IS 'Description of the sequence.';

 

=={{header|Stata}}==

For instance, say we have an ado file '''hello.ado''':

 

di "Hello, World!"

 

The documentation file, '''hello.sthlp''', could be:

=={{header|Swift}}==

Swift uses reStructuredText. [http://nshipster.com/swift-documentation/ This third-party article] has some information.

Adds two numbers

:param: a an integer.

func add(a: Int, b: Int) -> Int {

return a + b

 

=={{header|Tcl}}==

Documentation for Tcl code is usually prepared in separate files using a tool like [http://wiki.tcl.tk/3054 doctools], but inline docs (with all their inherent limitations) can be done with the likes of [http://www.xs4all.nl/~rfsber/Robo/index.html Robodoc]. For example:

# FUNCTION

# TclDocDemo is a simple illustration of how to do documentation

proc TclDocDemo {foo bar} {

puts [format "%s -- %s" $foo $bar]

Both doctools and robodoc can produce output in multiple formats.

 

 

However, there are currently no special tools for extracting documentation comments that I'm aware of.

var mol = 42

 

System.print("'%(smol)' + 123 = %(add.call(mol, 123))")

System.print("'%(smol)' reversed = %(StrUtil.reverse(smol))")

 

{{out}}

'meaning of life' capitalized = Meaning of life

</pre>

 

=={{header|ZX Spectrum Basic}}==

Inline documentation is limited to comments within the code. However, there is no inbuilt extraction tool, so this would need to be written. The example shows how documentation for a variable and a function could be embedded within the code:

 

 

Alternatively, it is possible to embed documentation into LPRINT statements within a subroutine, allowing the language to print its own documentation. In the example below, the command GOSUB 2000 would print the documentation:

 

1999 STOP

2000 REM Print the documentation

2020 LPRINT "s is a function that takes a single numeric parameter and returns"

2030 LPRINT "its square"

 

{{omit from|GUISS}}