Module:module documentation
- The following documentation is located at Module:module documentation/documentation. [edit]
- Useful links: subpage list • links • transclusions • testcases • sandbox
This module automatically generates documentation for other modules. It fetches in-line comments in Lua code and converts them into a form that can be used on a documentation page via {{module documentation}}
. In fact, this module's documentation is an example of it in action!
It's helpful to do documentation this way, as it means function/method documentation is available in two places: at the top of the module page (as conventional Wikitext), and above the function itself (as a Lua comment). Each suits a different kind of editing style, and doing it this way keeps them synchronised.
A section of documentation is given using Lua's multi-line comment syntax, which looks something like this: --[==[ ... ]==]
. The number of equal signs should normally be two in order for the documentation to be properly snarfed by {{module documentation}}
. The following conventions can be used inside of the documentation:
- Long lines (both in regular paragraphs and in list items) can be broken by newlines optionally followed by spaces or tabs (especially useful in lists, to make the raw comment more readable). In such a case, the newline is converted to a space. Use two newlines in a row to break paragraphs. In general, it's recommended to break lines after at most 120 characters, to facilitate reading the raw comment.
- Template calls (using two braces) can be inserted literally and will be expanded.
- Single braces can be used to surround literal text, and will automatically be syntax-highlighted as Lua code. Nested braces inside of this literal text will be properly handled as long as they're balanced. If the first character of the literal text is itelf a brace, put a space before it (but not at the end), and it will be ignored.
- Backquotes can be used to surround literal text, which will be displayed using
<code>...</code>
. The stuff inside of backquotes cannot contain a backquote (except for double-backquoted placeholder variable names) or extend to multiple lines. - Double backquotes can be used to surround placeholder variable names, which will be displayed using
<var>...</var>
. The stuff inside of backquotes can only contain letters, numbers, underscores, hyphens and periods. Normally, such placeholders should be displayed in a monospace font, as if surrounded by<code>...</code>
. This effect can be achieved by using triple backquotes, which effectively uses the double-backquote syntax inside the single-backquote syntax.
Certain special directives can follow the opening multiline comment indicator, if placed on the same line as the indicator. In particular, the following directives are currently recognized:
- The directive
intro:
by itself signals introductory text, which will be placed at the beginning, prior to function documentation. This is useful to give a general introduction/overview of the module. - The directive
func: export.function(arg1, arg2, ...)
can be used when documenting a function declared in a nonstandard way (e.g. through a metatable, through an anonymous or locally-declared function assigned to theexport
table, etc.). The directive indicates the desired way for the function to appear, and the remainder of the comment describes the function's operation, as usual.
export.show
[edit]function export.show(frame)
The main entrypoint for {{module documentation}}
. The frame object can contain 3 optional arguments:
|comment_level=
: The number of equals signs (=) a given section uses. Default: 2 (i.e.--[==[ ... (comment block) ]==]
)- e.g. The value 4 means
--[====[ ... (comment block) ]====]
.
- e.g. The value 4 means
|section_level=
: The header level used for each function/method. Default: 2 (i.e. L2:== ... ==
).|identifier=
: A Lua string pattern. Only the comments of functions whose names match this pattern are used. When not given, all function are accepted.- This is useful when giving object methods, using a pattern such as
^object_name:
.
- This is useful when giving object methods, using a pattern such as
local m_str_utils = require("Module:string utilities")
local codepoint = m_str_utils.codepoint
local concat = table.concat
local insert = table.insert
local u = m_str_utils.char
local rsplit = m_str_utils.split
local export = {}
--[===[ intro:
This module automatically generates documentation for other modules. It fetches in-line comments in Lua code and
converts them into a form that can be used on a documentation page via {{tl|module documentation}}. In fact, this
module's documentation is an example of it in action!
It's helpful to do documentation this way, as it means function/method documentation is available in two places:
at the top of the module page (as conventional Wikitext), and above the function itself (as a Lua comment). Each
suits a different kind of editing style, and doing it this way keeps them synchronised.
A section of documentation is given using Lua's multi-line comment syntax, which looks something like this:
{--[==[ ... ]==]}. The number of equal signs should normally be two in order for the documentation to be properly
snarfed by {{tl|module documentation}}. The following conventions can be used inside of the documentation:
# Long lines (both in regular paragraphs and in list items) can be broken by newlines optionally followed by spaces
or tabs (especially useful in lists, to make the raw comment more readable). In such a case, the newline is converted
to a space. Use two newlines in a row to break paragraphs. In general, it's recommended to break lines after at most
120 characters, to facilitate reading the raw comment.
# Template calls (using two braces) can be inserted literally and will be expanded.
# Single braces can be used to surround literal text, and will automatically be syntax-highlighted as Lua code. Nested
braces inside of this literal text will be properly handled as long as they're balanced. If the first character of the
literal text is itelf a brace, put a space before it (but not at the end), and it will be ignored.
# Backquotes can be used to surround literal text, which will be displayed using {<code>...</code>}. The stuff inside of
backquotes cannot contain a backquote (except for double-backquoted placeholder variable names) or extend to multiple
lines.
# Double backquotes can be used to surround placeholder variable names, which will be displayed using {<var>...</var>}.
The stuff inside of backquotes can only contain letters, numbers, underscores, hyphens and periods. Normally, such
placeholders should be displayed in a monospace font, as if surrounded by {<code>...</code>}. This effect can be
achieved by using triple backquotes, which effectively uses the double-backquote syntax inside the single-backquote
syntax.
Certain special directives can follow the opening multiline comment indicator, if placed on the same line as the
indicator. In particular, the following directives are currently recognized:
* The directive `intro:` by itself signals introductory text, which will be placed at the beginning, prior to function
documentation. This is useful to give a general introduction/overview of the module.
* The directive `func: export.<var>function</var>(<var>arg1</var>, <var>arg2</var>, ...)` can be used when documenting a
function declared in a nonstandard way (e.g. through a metatable, through an anonymous or locally-declared function
assigned to the `export` table, etc.). The directive indicates the desired way for the function to appear, and the
remainder of the comment describes the function's operation, as usual.
]===]
local TEMP_LEFT_BRACE = u(0xFFF0)
local TEMP_NEWLINE = u(0xFFF1)
local function format_doc(str)
local code_blocks = {}
local code_blocks_i = 0
local private_use_start = 0x100000
local subbed_str = (str
-- Multiline literal text between backquotes; you can't use <pre> or <syntaxhighlight> because that
-- disables Wikitext parsing for <var>...</var>, italics, <span>...</span> etc. Instead use the trick of
-- putting a space at the beginning of each line, which yields monospace text without disabling Wikitext
-- interpretation.
:gsub("```(.-)```", function(inside)
return inside
-- placeholder variable names between double backquotes; we need to repeat this here to avoid
-- the following pattern for single backquotes from clobbering double backquotes
:gsub("``([A-Za-z0-9_%-. ]+)``", "<var>%1</var>")
-- single backquotes undo monospacing
:gsub("`([^`\n]+)`", '<span style="font-family: sans-serif;">%1</span>')
-- text on the first line should be monospaced
:gsub("^([^\n])", " %1")
-- text after a newline should be monospaced, and temp-escape the newline so later replacements
-- to join continued lines in a paragraph don't take effect
:gsub("\n", TEMP_NEWLINE .. " ")
-- escape { so it won't be interpreted as a code block
:gsub("{", TEMP_LEFT_BRACE)
end)
:gsub("``([A-Za-z0-9_%-. ]+)``", "<var>%1</var>") -- placeholder variable names between double backquotes
:gsub("`([^`\n]+)`", function(inside) -- literal text between backquotes, set using <code>...</code>
-- Escape { so it won't be interpreted as a code block.
inside = inside:gsub("{", TEMP_LEFT_BRACE)
return "<code>" .. inside .. "</code>"
end)
-- {} blocks: blocks of code
-- Escape to avoid removing line breaks.
:gsub("%b{}", function(m0)
local next_char = m0:sub(2, 2)
if next_char == "|" then
-- Wikitable; don't try to parse it as code. But we do want to parse special syntax in them (in
-- particular {...} syntax for embedded code snippets), and if we return nil that won't happen.
-- Instead, we call format_doc() recursively on the innards.
return "{" .. format_doc(m0:sub(2, -2)) .. "}"
end
if next_char == "{" and m0:sub(-2, -2) == "}" then return nil end
local text = "<syntaxhighlight lang=lua" .. (m0:match("\n") and "" or " inline") .. ">" .. m0:sub(2, -2):gsub("^ +", "") .. "</syntaxhighlight>"
-- Prevent any further processing by storing the desired text into the `code_blocks` array and replacing
-- the whole thing with a single private-use-area character.
code_blocks_i = code_blocks_i + 1
code_blocks[code_blocks_i] = text
return u(private_use_start + code_blocks_i)
end)
-- undo escaping of left brace to prevent code block interpretation
:gsub(TEMP_LEFT_BRACE, "{")
-- Join continued lines in a paragraph. We don't want to do that if there are two newlines in a row,
-- and not if the second line begins with whitespace or a certain special characters (#, * or : indicating
-- a list item; | indicating a wikitable item; semicolon for bolded items).
:gsub("([^\n])\n[ \t]*([^ \t\n#*:;|])", "%1 %2")
-- Repeat the previous in case of a single-character line (admittedly rare).
:gsub("([^\n])\n[ \t]*([^ \t\n#*:;|])", "%1 %2")
:gsub("\n[ \t]+%f[*#:;]", "\n") -- remove indentation for list items
:gsub("%f[\n,{]\n%f[^\n*#:;]", "\n\n") -- wiki newlines
:gsub("(\n[ *#:]*)(|?[_%w]+=?):", "%1<code><b>%2</b></code>:") -- parameter names
-- double-underline to indicate types (displayed as italicized underlined)
:gsub("__(.-)__", function(inside)
return "<u><i>" .. inside .. "</i></u>"
end)
-- undo escaping of newline to prevent joining of continued lines
:gsub(TEMP_NEWLINE, "\n"))
-- Put <code>...</code> around <var>...</var> invocations that don't already occur inside of
-- <code>...</code> blocks.
local split_on_code = rsplit(subbed_str, "(<code>.-</code>)")
for i = 1, #split_on_code, 2 do
split_on_code[i] = split_on_code[i]:gsub("(<var>.-</var>)", "<code>%1</code>")
end
subbed_str = concat(split_on_code)
return (subbed_str
-- Undo code-block stashing.
:gsub("\244[\128-\191][\128-\191][\128-\191]", function(char)
return code_blocks[codepoint(char) - private_use_start]
end))
end
--[===[
The main entrypoint for {{tl|module documentation}}. The frame object can contain 3 optional arguments:
* |comment_level=: The number of equals signs (=) a given section uses. Default: 2 (i.e. {--[==[ ... (comment block) ]==]})
*: e.g. The value 4 means {--[====[ ... (comment block) ]====]}.
* |section_level=: The header level used for each function/method. Default: 2 (i.e. L2: {== ... ==}).
* |identifier=: A Lua string pattern. Only the comments of functions whose names match this pattern are used. When not given, all function are accepted.
*: This is useful when giving object methods, using a pattern such as {^object_name:}.
]===]
function export.show(frame)
local args = frame:getParent().args or {}
local comment_level = tonumber(args["comment_level"]) or 2
local function make_comment_pattern(typeid)
if typeid then
typeid = "%s*" .. typeid
else
typeid = ""
end
return "%-%-%[" .. ("="):rep(comment_level) .. "%[" .. typeid .. "\n?(.-)[\t\n]*]" .. ("="):rep(comment_level) .. "]()"
end
local fn_comment_pattern = make_comment_pattern(nil)
local intro_comment_pattern = make_comment_pattern("intro:")
local metafunc_comment_pattern = make_comment_pattern("func:%s*(([^\n(]+)[^\n)]+%))")
local section_mark = ("="):rep(tonumber(args["section_level"]) or 2)
local pattern_identifier = args["identifier"] or ""
local mod_title = mw.title.getCurrentTitle()
if mod_title.text:match("/documentation$") then return "(<i>The generated documentation is located at the module page.</i>)" end
local mod_text = mod_title:getContent()
if not mod_text then return "(<i>The module page does not exist now.</i>)" end
-- This contains function and intro documentation. Each element is a two-element list of {POSITION, DOCS} specifying
-- the generated documentation for a function and the character position in the file where it was found (for sorting
-- purposes).
local docs
local intro_comment = mod_text:match("^.-" .. intro_comment_pattern)
if intro_comment then
docs = { {1, format_doc(intro_comment) }}
else
docs = {}
end
-- Look for actual functions.
for p0, f, fn in mod_text:gmatch("()\n[ \t]*function +(([^\n(]+)[^\n)]+%))") do
if fn:match(pattern_identifier) then
local c = mod_text:sub(1, p0 - 1):match("^.*" .. fn_comment_pattern .. "%s*$")
insert(docs, {p0, section_mark .. fn .. section_mark .. "\n\n" .. "<syntaxhighlight lang=lua inline>function " ..
f .. "</syntaxhighlight>\n\n" .. format_doc(c or
'<strong class="error">This function lacks documentation. Please add a description of its usages, inputs and outputs, ' ..
"or its difference from similar functions, or make it local to remove it from the function list.</strong>" ..
"[[Category:Templates and modules needing documentation]]")})
end
end
-- Now look for comments with the function declaration inside them (used for metatable functions etc.).
for p0, f, fn, comment in mod_text:gmatch("()" .. metafunc_comment_pattern) do
insert(docs, {p0, section_mark .. fn .. section_mark .. "\n\n" .. "<syntaxhighlight lang=lua inline>function " .. f .. "</syntaxhighlight>\n\n" .. format_doc(comment)})
end
table.sort(docs, function(a, b) return a[1] < b[1] end)
local chunks = {}
for i, decl in ipairs(docs) do
insert(chunks, decl[2])
end
return frame:preprocess(concat(chunks, "\n\n"))
end
return export