Module:Formatnum

    From Commons

    Documentation for this module may be created at Module:Formatnum/doc

    -- This module is intended to replace the functionality of Template:Formatnum and related templates.
    local p = {}
    
    function p.main(frame)
        local args = frame:getParent().args
        local prec    = args.prec or ''
        local sep     = args.sep or ''
        local number  = args[1] or args.number or ''
        local lang    = args[2] or args.lang or ''
        -- validate the language parameter within MediaWiki's caller frame
        if lang == "arabic-indic" then -- only for back-compatibility ("arabic-indic" is not a SupportedLanguage)
            lang = "fa" -- better support than "ks"
        elseif lang == '' or not mw.language.isSupportedLanguage(lang) then
            -- Note that 'SupportedLanguages' are not necessarily 'BuiltinValidCodes', and so they are not necessarily
            -- 'KnownLanguages' (with a language name defined at least in the default localisation of the local wiki).
            -- But they all are ValidLanguageCodes (suitable as Wiki subpages or identifiers: no slash, colon, HTML tags, or entities)
            -- In addition, they do not contain any capital letter in order to be unique in page titles (restriction inexistant in BCP47),
            -- but they may violate the standard format of BCP47 language tags for specific needs in MediaWiki.
            -- Empty/unspecified and unsupported languages are treated here in Commons using the user's language,
            -- instead of the local 'ContentLanguage' of the Wiki.
            lang = frame:callParserFunction( "int", "lang" ) -- get user's chosen language
        end
        return p.formatNum(number, lang, prec, sep ~= '')
    end
    
    local digit = { -- substitution of decimal digits for languages not supported by mw.language:formatNum() in core Lua libraries for MediaWiki
        ["ml-old"] = { '൦', '൧', '൨', '൩', '൪', '൫', '൬', '൭', '൮', '൯' },
        ["mn"]     = { '᠐', '᠑', '᠒', '᠓', '᠔', '᠕', '᠖', '᠗', '᠘', '᠙'},
        ["ta"]     = { '௦', '௧', '௨', '௩', '௪', '௫', '௬', '௭', '௮', '௯'},
        ["te"]     = { '౦', '౧', '౨', '౩', '౪', '౫', '౬', '౭', '౮', '౯'},
        ["th"]     = { '๐', '๑', '๒', '๓', '๔', '๕', '๖', '๗', '๘', '๙'}
    }
    
    function p.formatNum(number, lang, prec, compact)
    
        -- Do not alter the specified value when it is not a valid number, return it as is
        local value = tonumber(number)
        if value == nil then
            return number
        end
        -- Basic ASCII-only formatting (without paddings)
        number = tostring(value)
    
        -- Check the presence of an exponent (incorrectly managed in mw.language:FormatNum() and even forgotten due to an internal bug, e.g. in Hindi)
        local exponent
        local pos = string.find(number, '[Ee]')
        if pos ~= nil then
            exponent = string.sub(number, pos + 1, string.len(number))
            number = string.sub(number, 1, pos - 1)
        else
            exponent = ''
        end
    
        -- Check the minimum precision requested
        prec = tonumber(prec) -- nil if not specified as a true number
        if prec ~= nil then
            prec = math.floor(prec)
            if prec < 0 then
                prec = nil -- discard an incorrect precision (not a positive integer)
            elseif prec > 14 then
                prec = 14 -- maximum precision supported by tostring(number)
            end
        end
    
        -- Preprocess the minimum precision in the ASCII string
        local dot
        if (prec or 0) > 0 then
            pos = string.find(number, '.', 1, true) -- plain search, no regexp
            if pos ~= nil then
                prec = pos + prec - string.len(number) -- effective number of trailing decimals to add or remove
                dot = '' -- already present
            else
                dot = '.' -- must be added
            end
        else
            dot = '' -- don't add dot
            prec = 0 -- don't alter the precision
        end
    
        if lang ~= nil and mw.language.isKnownLanguageTag(lang) == true then
            -- Convert number to localized digits, decimal separator, and group separators
            local language = mw.getLanguage(lang)
            if compact then
                number = language:formatNum(tonumber(number), { noCommafy = 'y' }) -- caveat: can load localized resources for up to 20 languages
            else
                number = language:formatNum(tonumber(number)) -- caveat: can load localized resources for up to 20 languages
            end
            -- Postprocessing the precision
            if prec > 0 then
                local zero = language:formatNum(0)
                number = number .. dot .. mw.ustring.rep(zero, prec)
            elseif prec < 0 then
                -- TODO: rounding of last decimal; here only truncate decimals in excess
                number = mw.ustring.sub(number, 1, mw.ustring.len(number) + prec)
            end
    
            -- Append the localized base-10 exponent without grouping separators (there's no reliable way to detect a localized leading symbol 'E')
            if exponent ~= '' then
                number = number .. 'E' .. language:formatNum(tonumber(exponent),{noCommafy=true})
            end
        else -- not localized, ASCII only
            -- Postprocessing the precision
            if prec > 0 then
                number = number .. dot .. mw.string.rep('0', prec)
            elseif prec < 0 then
                -- TODO: rounding of last decimal; here only truncate decimals in excess
                number = mw.string.sub(number, 1, mw.string.len(number) + prec)
            end
    
            -- Append the base-10 exponent
            if exponent ~= '' then
                number = number .. 'E' .. exponent
            end
        end
    
        -- Special cases for substitution of ASCII digits (missing support in Lua core libraries for some languages)
        if digit[lang] then
            for i, v in ipairs(digit[lang]) do
                number = mw.ustring.gsub(number, tostring(i - 1), v)
            end
        end
    
        return number
    end
    
    return p