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util/array.lua @ 918:967edf874df7
util.array: New array library
| author | Matthew Wild <mwild1@gmail.com> |
|---|---|
| date | Wed, 25 Mar 2009 03:00:09 +0000 |
| child | 920:e302cbc9d036 |
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| 917:f12f88b3d4a1 | 918:967edf874df7 |
|---|---|
| 1 local array_methods = {}; | |
| 2 local array_mt = { __index = array_methods, __tostring = function (array) return array:concat(", "); end }; | |
| 3 | |
| 4 local function array(t) | |
| 5 return setmetatable(t or {}, array_mt); | |
| 6 end | |
| 7 | |
| 8 function array_methods:map(func, t2) | |
| 9 local t2 = t2 or array{}; | |
| 10 for k,v in ipairs(self) do | |
| 11 t2[k] = func(v); | |
| 12 end | |
| 13 return t2; | |
| 14 end | |
| 15 | |
| 16 function array_methods:filter(func, t2) | |
| 17 local t2 = t2 or array{}; | |
| 18 for k,v in ipairs(self) do | |
| 19 if func(v) then | |
| 20 t2:push(v); | |
| 21 end | |
| 22 end | |
| 23 return t2; | |
| 24 end | |
| 25 | |
| 26 | |
| 27 array_methods.push = table.insert; | |
| 28 array_methods.pop = table.remove; | |
| 29 array_methods.sort = table.sort; | |
| 30 array_methods.concat = table.concat; | |
| 31 array_methods.length = function (t) return #t; end | |
| 32 | |
| 33 function array_methods:random() | |
| 34 return self[math.random(1,#self)]; | |
| 35 end | |
| 36 | |
| 37 function array_methods:shuffle() | |
| 38 local len = #self; | |
| 39 for i=1,#self do | |
| 40 local r = math.random(i,len); | |
| 41 self[i], self[r] = self[r], self[i]; | |
| 42 end | |
| 43 end | |
| 44 | |
| 45 _G.array = array |