Lua 4.04.0

1 files changed, 29 insertions, 1 deletions

diff --git a/test/fib.lua b/test/fib.lua
index 881cbdc3..d946946a 100644
--- a/test/fib.lua
+++ b/test/fib.lua
@@ -1,6 +1,7 @@
 -- very inefficient fibonacci function
 
 function fib(n)
+	N=N+1
 	if n<2 then
 		return n
 	else
@@ -8,4 +9,31 @@ function fib(n)
 	end
 end
 
-print(fib(20))
+-- a much faster cached version
+
+function cache(f)
+	local c={}
+	return function (x)
+		local y=%c[x]
+		if not y then
+			y=%f(x)
+			%c[x]=y
+		end
+		return y
+	end
+end
+
+function test(s)
+	N=0
+	local c=clock()
+	local v=fib(n)
+	local t=clock()-c
+	print(s,n,v,t,N)
+end
+
+n=n or 24		-- for other values, do lua -e n=XX fib.lua
+n=tonumber(n)
+print("","n","value","time","evals")
+test("plain")
+fib=cache(fib)
+test("cached")