foundryvtt-swade-fr/tools/luajson/json/encode/output_utility.lua

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2022-05-28 09:30:19 +02:00
--[[
Licensed according to the included 'LICENSE' document
Author: Thomas Harning Jr <harningt@gmail.com>
]]
local setmetatable = setmetatable
local assert, loadstring = assert, loadstring or load
local _ENV = nil
-- Key == weak, if main key goes away, then cache cleared
local outputCache = setmetatable({}, {__mode = 'k'})
-- TODO: inner tables weak?
local function buildFunction(nextValues, innerValue, valueWriter, innerWriter)
local putInner = ""
if innerValue and innerWriter then
-- Prepare the lua-string representation of the separator to put in between values
local formattedInnerValue = ("%q"):format(innerValue)
-- Fill in the condition %WRITE_INNER% and the %INNER_VALUE% to actually write
putInner = innerWriter:gsub("%%WRITE_INNER%%", "%%1"):gsub("%%INNER_VALUE%%", formattedInnerValue)
end
-- Template-in the value writer (if present) and its conditional argument
local functionCode = nextValues:gsub("PUTINNER(%b())", putInner)
-- %VALUE% is to be filled in by the value-to-write
valueWriter = valueWriter:gsub("%%VALUE%%", "%%1")
-- Template-in the value writer with its argument
functionCode = functionCode:gsub("PUTVALUE(%b())", valueWriter)
functionCode = [[
return function(composite, ret, encode, state)
]] .. functionCode .. [[
end
]]
return assert(loadstring(functionCode))()
end
local function prepareEncoder(cacheKey, nextValues, innerValue, valueWriter, innerWriter)
local cache = outputCache[cacheKey]
if not cache then
cache = {}
outputCache[cacheKey] = cache
end
local fun = cache[nextValues]
if not fun then
fun = buildFunction(nextValues, innerValue, valueWriter, innerWriter)
cache[nextValues] = fun
end
return fun
end
local output_utility = {
prepareEncoder = prepareEncoder
}
return output_utility