Re: Recipe: setfenv with Lua 5.2.0 work3

["Juris Kalnins" <juris@...>]

On Tue, 15 Jun 2010 06:31:29 +0300, David Manura <dm.lua@math2.org> wrote:


> > In these discussions in the list, sometimes it looks like people are
> > changing environments all the time, in all sorts of code.
[..]
> A tangential point on DSLs: environments or not, it often feels to me
> that fitting DSL's into unmodified Lua syntax in clunky.  I think it's
> because that unlike XML or s-expressions, Lua has a particular
> evaluation order (not pure data), can only be combined in certain ways
> (e.g. expressions v.s. statements), and omits order and multiplicity
> of key-value pair lists (tables), so the DSL must be fit into this
> "Lua" model.

Actually, XML trees map to Lua table constructors very nicely:

<n1 a1="1" a2="3"><n2/><n2 a3="3">lala</n2></n1>

becomes

n1 { a1=1, a2=3, n2 {}, n2 { a3=3, "lala" } }

Provided that attribute names are not integer numbers. This is
currently my main use of environment changing.