--[[
Copyright (c) 2013 Enrique García Cota
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:
The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
--]]
-- <nowiki>
--- Unindent resets the indentation level of mulitline strings.
-- It is useful for multiline strings inside functions and large tables.
-- This module serves as a utility function for string parsing, [[Global
-- Lua Modules/Testharness|Testharness]] test suites, [[Global Lua
-- Modules/I18n|I18n]] datastores.
--
-- Lua supports multiline strings in the format `[[\n...\n]]`. In general,
-- Lua does not outdent indented multiline strings out of the box. Though
-- Lua supports variable indentation in multiline strings, custom logic is
-- necessary to reset the string's indentation. This module adopts a
-- flexible approach based on string scanning.
--
-- Unlike Penlight's `pl.text.dedent` behaviour where every line has the
-- indentation of the first line removed, the line prefixed with the least
-- non-tab whitespace is reset to zero indentation. Thus, the opening line
-- of the string may retain some indentation *if* there are lines of less
-- indentation terminating the string.
--
-- @script unindent
-- @license MIT
-- @release stable
-- @author [[User:8nml|8nml]]
-- @attribution [[github:kikito|@kikito]] ([[github:kikito/inspect.lua/blob/master/spec/unindent.lua|Github]])
-- @param {string} str Multiline string indented consistently.
-- @returns {string} Unindented string.
return function(str)
str = str:gsub(' +$', ''):gsub('^ +', '') -- remove spaces at start and end
local level = math.huge
local minPrefix = ''
local len
for prefix in str:gmatch('\n( +)') do
len = #prefix
if len < level then
level = len
minPrefix = prefix
end
end
return (str:gsub('\n' .. minPrefix, '\n'):gsub('\n$', ''))
end
