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author | chai <chaifix@163.com> | 2018-12-07 01:18:45 +0800 |
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committer | chai <chaifix@163.com> | 2018-12-07 01:18:45 +0800 |
commit | afc5ebdeece428d4ef72f4f1f4b178a92d1b9cba (patch) | |
tree | 664aff4bdf9841346f044cb2a2f3cb4b55eba386 /src/3rdparty/lua-5.1.5/test/factorial.lua | |
parent | 1acc1ecf398bc43bc304a449643fddbb65d1e733 (diff) |
+lua51
Diffstat (limited to 'src/3rdparty/lua-5.1.5/test/factorial.lua')
-rw-r--r-- | src/3rdparty/lua-5.1.5/test/factorial.lua | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/src/3rdparty/lua-5.1.5/test/factorial.lua b/src/3rdparty/lua-5.1.5/test/factorial.lua new file mode 100644 index 0000000..7c4cf0f --- /dev/null +++ b/src/3rdparty/lua-5.1.5/test/factorial.lua @@ -0,0 +1,32 @@ +-- function closures are powerful + +-- traditional fixed-point operator from functional programming +Y = function (g) + local a = function (f) return f(f) end + return a(function (f) + return g(function (x) + local c=f(f) + return c(x) + end) + end) +end + + +-- factorial without recursion +F = function (f) + return function (n) + if n == 0 then return 1 + else return n*f(n-1) end + end + end + +factorial = Y(F) -- factorial is the fixed point of F + +-- now test it +function test(x) + io.write(x,"! = ",factorial(x),"\n") +end + +for n=0,16 do + test(n) +end |