Patterns in SDF attributes could be used to make the imploded AST more attractive. This has two advantages: (1) it makes the AST more attractive without additional tools (duh) and (2) it might prevent too much grammar hacking to improve the implosion.

Patterns could be ATerms with placeholders. The placeholders can refer to arguments of the production rule. In this way, arguments of the production can be left out, or put in a different order.

Example:
Foo(Bar(<1>), “Fred”, <2>)

If we are going to introduce such a feature (would it be popular?) then this affects implode-asfix, sdf2rtg, and ast2abox.

Submitted on 31 October 2004 at 19:05

STR-197, martin:
Maybe, the placeholders should be SDF labels instead of numbers. This is a bit more stable.

STR-197, martin:
Maybe, it would be nice if you could also refer the LAYOUT and literal arguments. Of course, that cannot be easily expressed with labels, so we need numbers for that anyway.