Re: Experiments with Scripting Languages
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- Subject: Re: Experiments with Scripting Languages
- From: Roberto Ierusalimschy <roberto@...>
- Date: 2000年4月10日 16:55:23 -0300
> text/plain /home/roberto/lua/testes/bwk/lua-all
Sorry about that. Let me try again...
-- Roberto
=====================================================================
Suite of Lua scripts for "Experiments with Scripting and User-Interface
Languages", by Brian W. Kernighan & Christopher J. Van Wyk
(http://cm.bell-labs.com/cm/cs/who/bwk/interps/pap.html).
To change `lim', call "lua lim=XXXX prog.lua"
For instance, to compute ack(3,6), call
> lua lim=6 ack.lua
=====================================================================
-- ack.lua
-- ackerman function
lim = tonumber(lim) or 7
function ack(m, n)
if (m == 0) then
return n+1
elseif (n == 0) then
return ack(m-1, 1)
else
return ack(m-1, ack(m, n-1))
end
end
print(ack(3,lim))
=====================================================================
-- array1.lua
-- test for arrays
local n = tonumber(lim) or 100000
local x, y = {}, {}
local i = 1
while i<=n do
x[i] = i
i = i+1
end
local j = n
while j>=1 do
y[j] = x[j]
j = j-1
end
=====================================================================
-- assoc.lua
-- test for associative arrays
-- This test is very bad for Lua :-(. It takes much more time handling
-- strings (format and convertion from number to string) than in the tables
local n = tonumber(lim) or 10000
local i=1
local X={}
while i<=n do
X[format("%x", i)] = i
i = i+1
end
local c = 0
i = n
while i>0 do
if X[i..''] then c = c+1 end
i = i-1
end
print(c)
=====================================================================
-- cat.lua
-- cat: copies a file from stdin to stdout
local line = read()
while line do
write(line, "\n")
line = read()
end
=====================================================================
-- cat1.lua
-- cat: copies a file from stdin to stdout
-- reads the whole file at once
write(read"*a")
=====================================================================
-- string.lua
-- test for string manipulation
local n = tonumber(lim) or 100000
local s
local j = 1
while j<=10 do
s = "abcdef"
while strlen(s) <= n do
s = "123"..s.."456"..s.."789"
s = strsub(s, strlen(s)/2) .. strsub(s, 1, strlen(s)/2)
end
j = j+1
end
print(strlen(s))
=====================================================================
-- sum1.lua
-- add numbers in a file
local s = 0
local n = read"*n" -- reads a number
while n do
s = s+n
n = read"*n"
end
print(s)
=====================================================================
-- sumloop.lua
-- test for basic loops
local n = tonumber(lim) or 1000000
local s = 0
local i = 0
while i<n do
s=s+1
i=i+1
end
print(s)
=====================================================================
-- tail.lua
-- invert the lines of a file
local lines = {}
local nl = 0
local line = read()
while line do
nl = nl+1
lines[nl] = line
line = read()
end
while nl>=1 do
write(lines[nl], "\n")
nl=nl-1
end
=====================================================================
-- wc.lua
-- print the number of bytes, words, and lines of a file
local cc,lc,wc = 0,0,0
local line = read()
while line do
cc = cc+strlen(line)
lc = lc+1
local _,t = gsub(line, "%S+", "") -- count words in the line
wc = wc+t
line = read()
end
print(lc,wc,cc+lc) -- adds `lc' to `cc' to include newlines */
=====================================================================
-- wc1.lua
-- print the number of bytes, words, and lines of a file
-- read the whole file at once
local t = read"*a"
local cc = strlen(t)
local _,lc = gsub(t, "\n", "\n")
local _,wc = gsub(t, "%S+", "")
print(lc,wc,cc)