Module:Escape input

---

--- This module allows special Lua character sequences to be escaped and inserted
-- as parameters in arguments.
--  
-- In addition to those listed on [[mw:Extension:Scribunto/Lua_reference_manual#string]],
-- the following is how replacements are conducted:
--
-- {| class="wikitable"
-- ! Escape sequence !! Character
-- |-
-- | <code><nowiki>\{</nowiki></code> || <code><nowiki>{</nowiki></code>
-- |-
-- | <code><nowiki>\}</nowiki></code> || <code><nowiki>}</nowiki></code>
-- |-
-- | <code><nowiki>\[</nowiki></code> || <code><nowiki>[</nowiki></code>
-- |-
-- | <code><nowiki>\]</nowiki></code> || <code><nowiki>]</nowiki></code>
-- |-
-- | <code><nowiki>\p</nowiki></code> || <code><nowiki>|</nowiki></code>
-- |-
-- | <code><nowiki>\e</nowiki></code> || <code><nowiki>=</nowiki></code>
-- |-
-- | <code><nowiki>\_</nowiki></code> || <code><nowiki> </nowiki></code>
-- |}
--
-- @module escape_input
-- @alias p

local p = {}

--- Conducts the necessary replacement of the matched pattern string
-- @param {string} s Matched sequence to replace
-- @return Escaped character
local function replace( s )
	-- necessary replacement to make these characters work in the format string
	if s == '\\a' then return '\a'
	elseif s == '\\b' then return '\b'
	elseif s == '\\t' then return '\t'
	elseif s == '\\n' then return '\n'
	elseif s == '\\v' then return '\v'
	elseif s == '\\f' then return '\f'
	elseif s == '\\r' then return '\r'
	elseif s == '\\"' then return '\"'
	elseif s == '\\\'' then return '\''
	elseif s == '\\\\' then return '\\'
	-- additional custom escape sequences specific for wikitext markup
	elseif s == '\\{' then return '{'
	elseif s == '\\}' then return '}'
	elseif s == '\\[' then return '['
	elseif s == '\\]' then return ']'
	elseif s == '\\p' then return '|'
	elseif s == '\\e' then return '='
	elseif s == '\\_' then return ' '
	else return s
	end
end

--- Escapes a specified format string
--
-- @param {string} string String with escape characters
-- @return Escaped string
function p.escape( string )
	return mw.ustring.gsub( string, '\\.', replace )
end

--- Main entrypoint
--
-- @usage {{#invoke:escape input|main|1=String to escape}}
-- @param {table} frame Calling frame
-- @param {table} frame.args Frame arguments
-- @param {string} frame.args[1] Escaped string sequence
-- @return Escaped wikitext
function p.main( frame )
	return p.escape( frame.args[1] )
end

return p