> On Mar 8, 2018, at 5:11 PM, Jan Sulmont <[email protected]> wrote: > >> >> In a sense this question isn’t about Redex but the relationship between >> different frameworks of formulating a semantics. For some class of cases, >> this is systematically doable (that’s how I came up with the reduction >> semantics for h-o imperative generalization of the lambda calculus for >> example); for others, it is an open question. I know little about Orc and >> not enough to know which class it falls into. >> > Yes I’ve walked through the “Abstracting abstract machines” tutorial, where I > thought moving from judgment to reduction was only easy due to the > simplicity of the language under consideration.
It is not the simplicity of the language but the nature of the (recursive) evaluation strategy. The uniformity of lambda makes it easy to translate from trees into sequences and to discover what evaluation contexts are and mean. For an orchestration language or a pi calculus, this is rather different because you want some freedom of moving things around freely. Years ago we considered supporting sets of terms in redex and that might help with such languages. Right now you have to “mod out” with pattern-matching in Redex (or worse, procedurally if your pattern is highly unusual). You may wish to look at the work of Tony Garnock-Jones on Syndicate. His language evaluates in a somewhat non-uniform manner and we used structural rules for a while. For his dissertation though he was able to convert it all to reductions (and could state properties more cleanly that way). > >> >>> Like pairing a context with some state -- how should I convey/turn whatever >>> I mean with this state into syntax, so that meaningful syntactic reduction >>> can happen? >>> >>> Anyone could please point me at an example where the grammar has a pair >>> (context state) production? >> >> >> If I understand you correctly, the Redex book covers some of these examples >> (which we call machines). It might be the best place to get started. I am >> sure your local university library has a copy (or will get you one). > I’ve purchased my own copy of the Redex book — and am working slowly my way > through the 1st part (which I find very useful) > I am neither a student, nor working in the academic. I run Orc in a large > production :) Can you focus on a small kernel of Orc, something the size of pi or ccs? — Matthias -- You received this message because you are subscribed to the Google Groups "Racket Developers" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-dev/60F9DAA1-C24F-4CC6-AB6B-A8D6D889B361%40ccs.neu.edu. For more options, visit https://groups.google.com/d/optout.
