|Re: Attribute Grammars used in compi compilers@ima.UUCP (1986-01-07)|
|Re: Attribute Grammars used in compi compilers@ima.UUCP (1986-01-09)|
|Re: Attribute Grammars used in compi compilers@ima.UUCP (1986-01-15)|
|Relay-Version:||version B 2.10.2 9/12/84; site mit-hermes.ARPA|
|Posting-Version:||Notesfiles $Revision: 188.8.131.52 $; site ima.UUCP|
|Date:||7 Jan 86 03:13:00 GMT|
|Posted:||Mon Jan 6 22:13:00 1986|
|Date-Received:||7 Jan 86 10:46:25 GMT|
|Nf-From:||ima!compilers Jan 6 22:13:00 1986|
[from Eduardo Krell <think!ekrell@LOCUS.UCLA.EDU>]
In article <2287@burdvax.UUCP> wpl@burdvax.UUCP (William P Loftus) writes:
>Since A is copying attributes i and k from a child and also calculating
>attribute j from the same attributes, is it better to get the values (that
>j is calculated) from the children nodes or to calculate them from attributes
>in the same node?
You might want to read the following paper:
Martin, David and Chirica Laurian, ``An Order-Algebraic Definition
of Knuthian Systems'', Math. Systems Theory No. 13 (1979).
In this paper the authors prove that any AG with both synthesized and
inherited attributes can be transformed into an equivalent AG with only
synthesized attributes. They also show how to do it.
The price you pay for doing this is that some attributes are now in the
functional domain (i.e. some attributes are functions, not just plain
values). The payoffs, however, are tremendous since now you can process
your AG in a strictly top-down, syntax-directed scheme.
Eduardo Krell UCLA Computer Science Department
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