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On Tue, Dec 8, 2009 at 10:44 AM, steve donovan <> wrote:
On Mon, Dec 7, 2009 at 1:27 AM, Marcus Irven <> wrote:
> Announcing Underscore.lua --
> Underscore.lua is a utility library with 30+ (and growing) functions that
> can be used in a functional or object-oriented manner.

Nice, a well-chosen set of functionalities. I like how you've provided
some aliases.

I quote:

_.({1,2,3,4}):chain():map(function(i) return i+1
end):select(function(i) i%2 == 0 end):value()

First random observation: Lua people tend to use '_' as a throwaway
variable, in cases like 'local _,i2 = s:find('%s+')'.  But it can
always be aliased if necessary.

I thought of this as I use '_' for throwaway variables myself. I couldn't think of anything better though and since this is basically a rip off of the _javascript_ library I went with it. Plus as you pointed out you can use "__ = _:no_conflict()" or whatever.
Second, support for 'string lambdas' would be cool:

_.({1,2,3,4}):chain():map '|i| i + 1' :select '|i| i%2==0': value()

There's a slight hit to compile them, but thereafter they can be
easily memoized. They don't require any syntax enhancements so David K
can only have style objections ;)

This is an interesting idea, I'd have to either:
1) insert a 'return' so it would limit the string lambda to a single _expression_ 
2) have a complex parser
3) require the 'return' to be explicit (e.g. map '|i| return i + 1')

I'll play around with this idea, if anybody wants to submit any code I'd be happy to take a look.

> - I'd like a nice function for dumping any object as well as a good table
> equality function

As for table comparison, this is the one I use in Penlight:

steve d.