Re: package.config is a string?

[HyperHacker <hyperhacker@...>]

On Fri, Jun 11, 2010 at 21:58, David Manura <dm.lua@math2.org> wrote:
> On Thu, Jun 10, 2010 at 11:03 PM, joshua simmons <simmons.44@gmail.com> wrote:
>> Is there any great reason for package.config to be a string of elements
>> separated by new lines as opposed to a table of individual elements?
>> Especially when it contains very useful data like the system's path
>> separator.
>
> Having it be a table makes some sense, at the cost of a few extra
> objects in memory that might never be used in a program.
>
> The question I have is why package.path and package.cpath are strings
> rather than arrays.  If they were arrays--like their analogues in
> Python (sys.path), Perl (@INC), and Ruby ($:) and unlike in shell
> scripting (PATH), with Tcl perhaps in-between--user code wouldn't have
> to worry about parsing and constructing them using the value of
> LUA_PATH_SEP (";"), and loadlib.c:pushnexttemplate wouldn't need to
> re-parse it on each require.
>
> To append a path, which of these do you prefer?  Which would users
> more likely write correctly?  Which is easier to later undo?
>
>  table.insert(package.path, "./mylib/?.lua")
>  package.path = package.path .. package.config:sub(3,3) .. "./mylib/?.lua"
>
> Perl, BTW, has a very small convenience notation in the form of a
> pragma module [1] that expressed in Lua might look like `import("lib",
> "./mylib/?.lua")`, where `import(a,...)` is defined roughly as
> `require(a):__import(...)`, which in turn here does
> `table.insert(package.path, x)` for each `x` in `...`.  So, to load
> ./mylib/foo.lua, you would do something like `import("lib",
> "./mylib/?.lua"); import("foo")`.  An even shorter form (Ruby example
> [2]) would be `lib "./mylib/?.lua"` or just `lib "./mylib"` setting
> all ?.lua, ?.so, and ?/init.lua (Steve: suggest to penlight).  Perl 6,
> I understand, might also allow the search path to be a lexical so that
> changes to it are limited to lexical scope [3].
>
> [1] http://lua-users.org/lists/lua-l/2010-01/msg00456.html
> [2] http://blog.ljstech.net/2007/02/ruby-lib-path-manipulations.html
> [3] http://irclog.perlgeek.de/perl6/2010-06-12#i_2426382
>

These are both good points, and I'd like to also point out that
package.config doesn't seem to be in the 5.1 manual.

-- 
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