Data commit

Task/Currying/Lua/currying-1.lua

@@ -0,0 +1,17 @@
+function curry2(f)
+   return function(x)
+      return function(y)
+         return f(x,y)
+      end
+   end
+end
+
+function add(x,y)
+   return x+y
+end
+
+local adder = curry2(add)
+assert(adder(3)(4) == 3+4)
+local add2 = adder(2)
+assert(add2(3) == 2+3)
+assert(add2(5) == 2+5)

Task/Currying/Lua/currying-2.lua

@@ -0,0 +1,35 @@
+local curry do
+  local call,env = function(fn,...)return fn(...)end
+  local fmt,cat,rawset,rawget,floor = string.format,table.concat,rawset,rawget,math.floor
+  local curryHelper = setmetatable({},{
+    __call = function(me, n, m, ...)return me[n*256+m](...)end,
+    __index = function(me,k)
+      local n,m = floor(k / 256), k % 256
+      local r,s = {},{} for i=1,m do r[i],s[i]='_'..i,'_'..i end s[1+#s]='...'
+      r,s=cat(r,','),cat(s,',')
+      s = n<m and fmt('CALL(%s)',r) or fmt('function(...)return ME(%d,%d+select("#",...),%s)end',n,m,s)
+      local sc = fmt('local %s=... return %s',r,s)
+      rawset(me,k,(loadstring or load)(sc,'_',nil,env) )
+      return rawget(me,k)
+    end})
+  env = {CALL=call,ME=curryHelper,select=select}
+  function curry(...)
+    local pn,n,fn = select('#',...),...
+    if pn==1 then n,fn = debug.getinfo(n, 'u'),n ; n = n and n.nparams end
+    if type(n)~='number' or n~=floor(n)then return nil,'invalid curry'
+    elseif n<=0 then return fn -- edge case
+    else return curryHelper(n,1,fn)
+    end
+  end
+end
+
+-- test
+function add(x,y)
+   return x+y
+end
+
+local adder = curry(add) -- get params count from debug.getinfo
+assert(adder(3)(4) == 3+4)
+local add2 = adder(2)
+assert(add2(3) == 2+3)
+assert(add2(5) == 2+5)