Module:Road data/parser

local p = {} -- Package to be exported

-- Change to "" upon deployment. local moduleSuffix = ""

local parserHooksModuleName = "Module:Road data/parser/hooks" .. moduleSuffix

-- Local library aliases local format = string.format local gsub = mw.ustring.gsub local upper = mw.ustring.upper

--- -- Substitution pattern based on passed arguments -- Syntax: [param|value|match|mismatch] -- where -- param is the parameter name to be tested -- value is the value to test against argument; if empty, the argument is --    tested for existence -- match is the string to be substituted if the argument matches value -- mismatch is the string to be substituted if the argument does not match --   the value -- These arguments may not contain "[", "|", or "]". local prepattern = "%[(%w+)%|([^%[|%]]*)%|([^%[|%]]*)%|([^%[|%]]*)%]" --- -- Parameter substitution pattern -- Syntax: %param% -- where param is the name of the parameter whose value is to be substituted -- in place of %param%. local pattern = "%%(%w+)%%"

--- -- Perform substitutions. -- @param #string formatStr The string the be substituted -- @param #table args The arguments passed to this module local function subst(formatStr, args) ---	-- Perform a substitution based on passed argument. -- @param #string param The parameter name to be tested -- @param #string value The value to test against argument; if empty, -- 		the argument is tested for existence -- @param #string ifmatch The resulting string if the argument matches -- 		`value` -- @param #string ifmismatch The resulting string if the argument does not -- 		match `value` -- @return #string either `ifmatch` or `ifmismatch`, based on the test local function testArgs(param, value, ifmatch, ifmismatch) local arg = args[param] or '' if value ~= '' then return arg == value and ifmatch or ifmismatch else return arg ~= '' and ifmatch or ifmismatch end end -- argument-test substitutions local preprocessed = gsub(formatStr, prepattern, testArgs) -- parameter substitutions return (gsub(preprocessed, pattern, args)) -- gsub returns number of matches as second value. -- The enclosing parens discards it. end

--- -- Determine whether a given title exists on Wikipedia. -- @param #string name The title, e.g., article name and file name, -- 		without namespace prefix -- @param #string key The name of the entry being translated. -- @return #boolean `true` if the title exists, false otherwise local function titleExists(name, key) if name == '' then return false end local namespaceModule = mw.loadData('Module:Road data/parser/namespace') -- Retrieve the namespace for `key`. local namespace = namespaceModule[key] or 0 local title = mw.title.new(name, namespace); return title.exists end

--- -- Determine whether titles exist on Wikipedia. -- @param value A string or a table containing strings of titles to be checked -- 		against -- @param #string key The name of the entry being translated. -- @return #boolean `true` if all titles exist, false otherwise local function ifexists(value, key) local valueType = type(value) if valueType == "table" then -- If `value` is a table, recursively check the existence -- for each element within the table. for _,entry in pairs(value) do			if not ifexists(entry, key) then return false end end return true end -- Otherwise, `value` is a string, so check the existence for that string. return titleExists(value, key) end

--- -- Perform a translation on a given entry. -- @param entry An entry to be translated; may be any non-function type. -- 		A table may be a parser hook specification, a switch table, or an -- 		ordinary value table. Translations are applied recursively. -- @param #table args The arguments passed to this module -- @param #string key The name of the entry being translated. -- @return The translated entry local function translate(entry, args, key) if type(entry) == "string" then return subst(entry, args) -- Substitute arguments as necessary. elseif type(entry) ~= "table" then return entry elseif entry.hook then -- This entry is a parser hook. -- Requires: Parser hook must have hook field. local hook = entry.hook local parserHooksModule = require(parserHooksModuleName) local hookFunction = parserHooksModule[hook] or error("Hook '" .. hook .. "' does not exist", 0) return translate(hookFunction(entry, args), args, key) elseif entry.arg or entry.undefined or entry.default then -- This entry is a switch table. -- Requires: Switch table must have --          arg, undefined, or default fields --          but not hook field. local arg = args[entry.arg or "route"] if entry[arg] then return translate(entry[arg], args, key) end if arg == nil and entry.undefined ~= nil then -- result for unspecified argument return translate(entry.undefined, args, key) end -- default result for mismatch local defaultValue = translate(entry.default, args, key) if defaultValue and entry.ifexists then -- Check existence. if ifexists(defaultValue, key) then return defaultValue end -- Failed existence check results in fallback value (default to nil). return entry.otherwise and translate(entry.otherwise, args, key) or nil else return defaultValue end else -- This entry is a value table. -- Process each table element. local result = {} for key,elem in pairs(entry) do			result[key] = translate(elem, args, key) end return result end end

--- -- Retrieve an entry from a data module based on a given type and key. -- @param #string module The name of the data module to be fetched -- @param type The key for the type table within the loaded table -- @param key The key for the entry within the type table -- @return fetchedTable[type][key] if specified, where `fetchedTable` is the -- 		table fetched from `module`, nil otherwise local function getTypeData(module, type, key) -- Attempt to fetch the given data module. local success, moduleData = pcall(mw.loadData, module) if not success then return false, moduleData end -- Module could not be loaded -- The type table defaults to empty-key table if undefined. local typeTable = moduleData[type] or moduleData[''] -- Fallback table is the empty-key table, with the empty table as default. local defaultTable = moduleData[''] or {} if typeTable then local alias = typeTable.alias if alias and alias.module and alias.type then -- The type table is an alias table. -- Recursively fetch the aliased type data. local aliasedModule = "Module:Road data/strings/" .. alias.module local aliasedType = alias.type return getTypeData(aliasedModule, aliasedType, key) end return true, typeTable[key] or defaultTable[key] or nil else return true, nil end end

--- -- Determine the module name for the lookup by country and state. -- @param #table args The arguments passed to this module -- @return #string The module name to be fetched local function getModuleName(args) -- countries with submodules for states or provinces local stateCountries = {USA = true, CAN = true} local state = upper(args.state or args.province or '') local country if args.country then country = upper(args.country) else -- Recover the country from the given state or province. local countryModule = mw.loadData("Module:Road data/countrymask") country = countryModule[state] or 'UNK' end if stateCountries[country] and state ~= '' then -- Submodule within the country exists. return format("Module:Road data/strings/%s/%s", country, state) end return format("Module:Road data/strings/%s", country) end

--- -- Fetch the entry from the appropriate module, and return that entry -- substituted with appropriate values. -- @param #table args The arguments to be used for lookup and substitutions -- @param #string key The key for the entry within the type table -- @param #string type (optional) The key for the type table within the fetched -- 		module; defaults to args.type -- @param #string moduleName (optional) The name of the module to be fetched; -- 		defaults to the module determined by country and state -- @return The substituted entry function p.parser(args, key, type, moduleName) -- Determine module name, if not given. local dataModuleName = moduleName or getModuleName(args) -- Fetch the entry from the module. local success, formatStr = getTypeData(dataModuleName, type or args.type, key) if not success then return false, formatStr end -- Translate the entry. return translate(formatStr, args, key) end

return p