minix/external/mit/lua/dist/test/factorial.lua
Lionel Sambuc 11be35a165 Importing NetBSD "Kyua" test framework
To do so, a few dependencies have been imported:

 * external/bsd/lutok
 * external/mit/lua
 * external/public-domain/sqlite
 * external/public-domain/xz

The Kyua framework is the new generation of ATF (Automated Test
Framework), it is composed of:

 * external/bsd/atf
 * external/bsd/kyua-atf-compat
 * external/bsd/kyua-cli
 * external/bsd/kyua-tester
 * tests

Kyua/ATF being written in C++, it depends on libstdc++ which is
provided by GCC. As this is not part of the sources, Kyua is only
compiled when the native GCC utils are installed.

To install Kyua do the following:

 * In a cross-build enviromnent, add the following to the build.sh
   commandline: -V MKBINUTILS=yes -V MKGCCCMDS=yes

WARNING:
  At this point the import is still experimental, and not supported
  on native builds (a.k.a make build).

Change-Id: I26aee23c5bbd2d64adcb7c1beb98fe0d479d7ada
2013-07-23 20:43:41 +02:00

32 lines
707 B
Lua

-- 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