“Module:Road data/util”的意思、由来-开放百科全书

词条

Module:Road data/util

释义

local util = {}

local insert = table.insert

local concat = table.concat

local format = mw.ustring.format

-- Add all entries in `arr` into `target`.-- An error is raised if `overwrite` is not true-- and any key in `arr` is already in `target`.

function util.addAll(target, arr, overwrite)

if type(target) ~= "table" then

error("target is not a table")

end

for key,value in pairs(arr) do

if overwrite or target[key] == nil then

target[key] = value

else

error("Duplicate key: " .. tostring(key))

end

local function comp(e1, e2)

local t1 = type(e1)

local t2 = type(e2)

if t1 ~= t2 then return t1 < t2 end

if t1 == "function" then

error("Unexpected function type")

end

return e1 < e2

end

local arrayToStringAux

arrayToStringAux = function(arr, indent)

if type(arr) ~= "table" then

error("arr is not a table")

end

if type(indent) ~= "number" then

error("indent is not a number")

end

local result = {}

local keys = {}

for key in pairs(arr) do insert(keys, key) end

table.sort(keys, comp)

for _,key in ipairs(keys) do

local value = arr[key]

local keyPrint

if type(key) == "string" then

keyPrint = format("\\"%s\\"", key)

else

keyPrint = tostring(key)

end

local valuePrint

if type(value) == "table" then

valuePrint = format("{\%s\%s}",

arrayToStringAux(value, indent + 4),

string.rep(" ", indent))

elseif type(value) == "string" then

valuePrint = format("\\"%s\\"", value)

else

valuePrint = tostring(value)

end

insert(result, format("%s[%s] = %s",

string.rep(" ", indent),

keyPrint,

valuePrint))

end

return concat(result, ", \")

end

--- Return a string representation of `arr`.

function util.arrayToString(arr, indent)

return arrayToStringAux(arr, indent or 0)

end

local function convert(distance, multiplier, desiredPrec)

if type(distance) ~= "string" then

error("distance is not a string")

end

if type(multiplier) ~= "number" then

error("multiplier is not a number")

end

-- Import math functions.

local math = require "Module:Math"

-- This function returns the precision of a given string representing a number.

local precision = math._precision

-- This function returns the order of magnitude of a given string representing a number.

local order = math._order

-- This function rounds a given number to the given number of digits.

local round = math._precision_format

local prec = desiredPrec or precision(distance)

if not desiredPrec then

local ord = order(distance)

-- Adjust precision based on multiplier, as done in {{convert}}.

prec = prec - order(multiplier / 0.2)

end

local converted = distance * multiplier

local magnitude = order(converted)

if prec <= -magnitude then

-- Ensure the result has at least two significant digits.

prec = -magnitude + 1

end

return round(converted, prec)

end

--[[-

Convert length specified in one unit (mi or km) to length in the other unit.

@param #map<#string, #string> lengths

a map from unit to distance (as a string) in that unit;

may contain entry `prec` indicating desired conversion precision

@param #string blank text to be used if length is unspecified

@return #table a table containing the conversion result:

orig = source unit;

comp = target unit;

mi = length in miles;

ft = converted length in feet;

km = length in kilometers;

m = converted length in meters;

error = error message, if any

]]

function util.convertLengths(lengths, blank)

-- Import math functions.

local math = require "Module:Math"

-- In Lua, storing functions locally results in more efficient execution.

-- This function rounds a given number to the given number of digits.

local round = math._precision_format

-- This function returns the precision of a given string representing a number.

local precision = math._precision

local kmPerMile = 1.609344

local ftPerMile = 5280

-- The length in kilometers as passed to the function.

local km = lengths.km

-- The length in miles as passed to the function.

local mi = lengths.mi

-- Precision for the converted length.

local prec = lengths.prec

local errMsg = {}

-- Sanitize inputs.

local km_ = tonumber(km)

if km and not km_ then

insert(errMsg, util.err("km is not a number"))

end

local mi_ = tonumber(mi)

if mi and not mi_ then

insert(errMsg, util.err("mi is not a number"))

end

local prec_ = tonumber(prec)

if prec and not prec_ then

insert(errMsg, util.err("prec is not a number"))

end

prec = prec_

local ft

local m

local orig = "mi"

local comp = "km"

if mi and km then

insert(errMsg, util.err("Both mi and km are specified"))

elseif mi then

-- Length in miles was passed.

if mi_ then

-- If `mi` is indeed a number, compute and round the length in kilometers.

km = convert(mi, kmPerMile, prec)

m = convert(mi, kmPerMile * 1000, prec)

-- format mi (insert separators as in 1,000)

mi = round(mi_, precision(mi))

else

-- `mi` is not a number.

km = blank

m = blank

end

elseif km then

-- Length in kilometers was passed.

-- Swap units.

orig, comp = comp, orig

if km_ then

-- If `km` is indeed a number, compute and round the length in miles.

mi = convert(km, 1 / kmPerMile, prec)

ft = convert(km, ftPerMile / kmPerMile, prec)

-- format km (insert separators as in 1,000)

km = round(km_, precision(km))

else

-- `km` is not a number.

mi = blank

ft = blank

end

else

mi = blank

ft = blank

km = blank

m = blank

end

local error = concat(errMsg)

if error == "" then error = nil end

return {mi = mi, ft = ft, km = km, m = m, orig = orig, comp = comp,

error = error}

end

--- Generates wikitext error messages.

function util.err(msg)

if msg == nil then

error("Unspecified error message")

end

return format('Error: %s', msg)

end

return util

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