Hi Folks,

In the book, Structure and Interpretation of Computer Programs by Abelson,
Sussman, and Sussman, the authors assert that looping constructs (such as
xsl:for-each) are syntactic sugar:

>  One reason that the distinction between process and procedure
>  may be confusing is that most implementations of common languages
>  (including Java, C++, and C) are designed in such a way that the
>  interpretation of any recursive procedure consumes an amount of
>  memory that grows with the number of procedure calls, even when
>  the process described is, in principle, iterative. As a consequence,
>  these languages can describe iterative processes only by resorting
>  to special-purpose "looping constructs" such as do, repeat, until for,
>  and while. The implementation of Scheme ... does not share this defect.
>  It will execute an iterative process in constant space, even if the
>  iterative process is described by a recursive procedure. An implementation
>  with this property is called tail-recursive.

/Roger