Lazy Evaluation vs Macros

Question

I\'m used to lazy evaluation from Haskell, and find myself getting irritated with eager-by-default languages now that I\'ve used lazy evaluation properly. This is actually q

Answer 1

Lazy evaluation can substitute for certain uses of macros (those which delay evaluation to create control constructs) but the converse isn't really true. You can use macros to make delayed evaluation constructs more transparent -- see SRFI 41 (Streams) for an example of how: http://download.plt-scheme.org/doc/4.1.5/html/srfi-std/srfi-41/srfi-41.html

On top of this, you could write your own lazy IO primitives as well.

In my experience, however, pervasively lazy code in a strict language tends to introduce an overhead as compared to pervasively lazy code in a runtime designed to efficiently support it from the start -- which, mind you, is an implementation issue really.