CC-Tweaked/src/main/resources/assets/computercraft/lua/rom/apis/help.lua

104 lines
3.0 KiB
Lua

--- Provides an API to read help files.
--
-- @module help
local expect = dofile("rom/modules/main/cc/expect.lua").expect
local sPath = "/rom/help"
--- Returns a colon-separated list of directories where help files are searched
-- for. All directories are absolute.
--
-- @treturn string The current help search path, separated by colons.
-- @see help.setPath
function path()
return sPath
end
--- Sets the colon-seperated list of directories where help files are searched
-- for to `newPath`
--
-- @tparam string newPath The new path to use.
-- @usage help.setPath( "/disk/help/" )
-- @usage help.setPath( help.path() .. ":/myfolder/help/" )
-- @see help.path
function setPath( _sPath )
expect(1, _sPath, "string")
sPath = _sPath
end
--- Returns the location of the help file for the given topic.
--
-- @tparam string topic The topic to find
-- @treturn string|nil The path to the given topic's help file, or `nil` if it
-- cannot be found.
-- @usage print(help.lookup("disk"))
function lookup( _sTopic )
expect(1, _sTopic, "string")
-- Look on the path variable
for sPath in string.gmatch(sPath, "[^:]+") do
sPath = fs.combine( sPath, _sTopic )
if fs.exists( sPath ) and not fs.isDir( sPath ) then
return sPath
elseif fs.exists( sPath .. ".txt" ) and not fs.isDir( sPath .. ".txt" ) then
return sPath .. ".txt"
end
end
-- Not found
return nil
end
--- Returns a list of topics that can be looked up and/or displayed.
--
-- @treturn table A list of topics in alphabetical order.
function topics()
-- Add index
local tItems = {
[ "index" ] = true,
}
-- Add topics from the path
for sPath in string.gmatch(sPath, "[^:]+") do
if fs.isDir( sPath ) then
local tList = fs.list( sPath )
for _, sFile in pairs( tList ) do
if string.sub( sFile, 1, 1 ) ~= "." then
if not fs.isDir( fs.combine( sPath, sFile ) ) then
if #sFile > 4 and sFile:sub(-4) == ".txt" then
sFile = sFile:sub(1, -5)
end
tItems[ sFile ] = true
end
end
end
end
end
-- Sort and return
local tItemList = {}
for sItem in pairs( tItems ) do
table.insert( tItemList, sItem )
end
table.sort( tItemList )
return tItemList
end
--- Returns a list of topic endings that match the prefix. Can be used with
-- `read` to allow input of a help topic.
--
-- @tparam string prefix The prefix to match
-- @treturn table A list of matching topics.
function completeTopic( sText )
expect(1, sText, "string")
local tTopics = topics()
local tResults = {}
for n = 1, #tTopics do
local sTopic = tTopics[n]
if #sTopic > #sText and string.sub( sTopic, 1, #sText ) == sText then
table.insert( tResults, string.sub( sTopic, #sText + 1 ) )
end
end
return tResults
end