Module:Math: Difference between revisions
simplify using a new binary_fold function, per protected edit request by User:Esquivalience
m>Mr. Stradivarius (get #expr without a frame, don't make unnecessary wrappers, and lazily initialise dependent modules, per protected edit request by User:Jackmcbarn) |
m>Mr. Stradivarius (simplify using a new binary_fold function, per protected edit request by User:Esquivalience) |
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end | end | ||
local function | local function fold(func, ...) | ||
-- Use a function on all supplied arguments, and return the result. The function must accept two numbers as parameters, | -- Use a function on all supplied arguments, and return the result. The function must accept two numbers as parameters, | ||
-- and must return a number as an output. This number is then supplied as input to the next function call. | -- and must return a number as an output. This number is then supplied as input to the next function call. | ||
| Line 63: | Line 63: | ||
end | end | ||
return ret, count | return ret, count | ||
end | |||
--[[ | |||
Fold arguments by selectively choosing values (func should return when to choose the current "dominant" value). | |||
]] | |||
local function binary_fold(func, ...) | |||
local value = fold((function(a, b) if func(a, b) then return a else return b end end), ...) | |||
return value | |||
end | end | ||
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return result | return result | ||
end | end | ||
--[[ | --[[ | ||
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function p._max(...) | function p._max(...) | ||
local function | local max_value = binary_fold((function(a, b) return a > b end), ...) | ||
if max_value then | if max_value then | ||
return max_value | return max_value | ||
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function p._min(...) | function p._min(...) | ||
local function | local min_value = binary_fold((function(a, b) return a < b end), ...) | ||
if min_value then | if min_value then | ||
return min_value | return min_value | ||
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function p._average(...) | function p._average(...) | ||
local function | local sum, count = fold((function(a, b) return a + b end), ...) | ||
if not sum then | if not sum then | ||
return 0 | return 0 | ||
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return oldr | return oldr | ||
end | end | ||
local result, count = | local result, count = fold(findGcd, ...) | ||
return result | return result | ||
end | end | ||