minix/external/mit/lua/dist/test/sort.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

66 lines
1.5 KiB
Lua

-- two implementations of a sort function
-- this is an example only. Lua has now a built-in function "sort"
-- extracted from Programming Pearls, page 110
function qsort(x,l,u,f)
if l<u then
local m=math.random(u-(l-1))+l-1 -- choose a random pivot in range l..u
x[l],x[m]=x[m],x[l] -- swap pivot to first position
local t=x[l] -- pivot value
m=l
local i=l+1
while i<=u do
-- invariant: x[l+1..m] < t <= x[m+1..i-1]
if f(x[i],t) then
m=m+1
x[m],x[i]=x[i],x[m] -- swap x[i] and x[m]
end
i=i+1
end
x[l],x[m]=x[m],x[l] -- swap pivot to a valid place
-- x[l+1..m-1] < x[m] <= x[m+1..u]
qsort(x,l,m-1,f)
qsort(x,m+1,u,f)
end
end
function selectionsort(x,n,f)
local i=1
while i<=n do
local m,j=i,i+1
while j<=n do
if f(x[j],x[m]) then m=j end
j=j+1
end
x[i],x[m]=x[m],x[i] -- swap x[i] and x[m]
i=i+1
end
end
function show(m,x)
io.write(m,"\n\t")
local i=1
while x[i] do
io.write(x[i])
i=i+1
if x[i] then io.write(",") end
end
io.write("\n")
end
function testsorts(x)
local n=1
while x[n] do n=n+1 end; n=n-1 -- count elements
show("original",x)
qsort(x,1,n,function (x,y) return x<y end)
show("after quicksort",x)
selectionsort(x,n,function (x,y) return x>y end)
show("after reverse selection sort",x)
qsort(x,1,n,function (x,y) return x<y end)
show("after quicksort again",x)
end
-- array to be sorted
x={"Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"}
testsorts(x)