From eea1bc04d759e6a0e51c0b008828eaa372790cdb Mon Sep 17 00:00:00 2001
From: Pierre Chapuis <catwell@archlinux.us>
Date: Wed, 23 Jan 2013 19:03:46 +0100
Subject: [PATCH] fix use of arg in ltn documentation
---
ltn012.wiki | 6 ++++--
ltn013.wiki | 6 +++---
2 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/ltn012.wiki b/ltn012.wiki
index b924dd3..96b13ae 100644
--- a/ltn012.wiki
+++ b/ltn012.wiki
@@ -126,8 +126,9 @@ local function chain2(f1, f2)
end
function filter.chain(...)
+ local arg = {...}
local f = arg[1]
- for i = 2, table.getn(arg) do
+ for i = 2, #arg do
f = chain2(f, arg[i])
end
return f
@@ -235,9 +236,10 @@ end
We can make these ideas even more powerful if we use a new feature of Lua 5.0: coroutines. Coroutines suffer from a great lack of advertisement, and I am going to play my part here. Just like lexical scoping, coroutines taste odd at first, but once you get used with the concept, it can save your day. I have to admit that using coroutines to implement our file source would be overkill, so let's implement a concatenated source factory instead.
{{{
function source.cat(...)
+ local arg = {...}
local co = coroutine.create(function()
local i = 1
- while i <= table.getn(arg) do
+ while i <= #arg do
local chunk, err = arg[i]()
if chunk then coroutine.yield(chunk)
elseif err then return nil, err
diff --git a/ltn013.wiki b/ltn013.wiki
index 734b433..a622424 100644
--- a/ltn013.wiki
+++ b/ltn013.wiki
@@ -73,12 +73,12 @@ Fortunately, all these problems are very easy to solve and that's what we do in
We used the {{pcall}} function to shield the user from errors that could be raised by the underlying implementation. Instead of directly using {{pcall}} (and thus duplicating code) every time we prefer a factory that does the same job:
{{{
local function pack(ok, ...)
- return ok, arg
+ return ok, {...}
end
function protect(f)
return function(...)
- local ok, ret = pack(pcall(f, unpack(arg)))
+ local ok, ret = pack(pcall(f, ...))
if ok then return unpack(ret)
else return nil, ret[1] end
end
@@ -157,7 +157,7 @@ function newtry(f)
if f then f() end
error(arg[2], 0)
else
- return unpack(arg)
+ return ...
end
end
end