Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Browse files
Browse the repository at this point in the history
Prodsigs and footprints reimplemented cleanly according to the forthc…
…oming paper
- Loading branch information
1 parent
073abd5
commit 777587d
Showing
1 changed file
with
92 additions
and
0 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,92 @@ | ||
@contributor{Vadim Zaytsev - vadim@grammarware.net - SWAT, CWI} | ||
module analyse::Prodsigs | ||
|
||
import syntax::BGF; | ||
import analyse::Metrics; | ||
import Set; | ||
|
||
data Footprint | ||
= fpnt() | ||
| fpopt() | ||
| fpplus() | ||
| fpstar() | ||
| fpmany(set[Footprint] fps) | ||
| fpempty() | ||
; | ||
|
||
alias Signature = rel[str,Footprint]; | ||
alias NameMatch = rel[str,str]; | ||
|
||
Footprint makefp(n, nonterminal(n)) = fpnt(); | ||
Footprint makefp(n, optional(nonterminal(n))) = fpopt(); | ||
Footprint makefp(n, plus(nonterminal(n))) = fpplus(); | ||
Footprint makefp(n, star(nonterminal(n))) = fpstar(); | ||
Footprint makefp(n, sequence(L)) = fpmany({makefp(e) | e <- L}); | ||
default Footprint makefp(str n, BGFExpression x) = fpempty(); | ||
|
||
Signature makesig(BGFProduction p) = {<n,makefp(n,p.rhs)> | n <- usedNs(p.rhs)}; | ||
|
||
bool eqfp(fpnt(), fpnt()) = true; | ||
bool eqfp(fpopt(), fpopt()) = true; | ||
bool eqfp(fpplus(), fpplus()) = true; | ||
bool eqfp(fpplus(), fpstar()) = true; | ||
bool eqfp(fpstar(), fpplus()) = true; | ||
bool eqfp(fpstar(), fpstar()) = true; | ||
bool eqfp(fpempty(), fpempty()) = true; | ||
bool eqfp(fpmany(L1), fpmany(L2)) | ||
{ | ||
//tuple[Footprint,set[Footprint]] | ||
<head,tail> = takeOneFrom(L1); | ||
for (e <- L2) | ||
if (eqfp(head,e)) | ||
return eqfp(tail, L2 - e); | ||
return false; | ||
} | ||
default bool eqfp(Footprint pi, Footprint xi) = false; | ||
|
||
// strong equivalence relies on natural equality of footprints | ||
// (i.e., == of rels) | ||
bool eqps(BGFProduction p1, BGFProduction p2) = eqps(makesig(p1),makesig(p2)); | ||
default bool eqps(Signature p, Signature q) = geqps(p,q,bool(p,q){return p == q;}); | ||
|
||
// weak equivalence relies on equivalence of footprints | ||
bool weqps(BGFProduction p1, BGFProduction p2) = weqps(makesig(p1),makesig(p2)); | ||
default bool weqps(Signature p, Signature q) = geqps(p,q,eqfp); | ||
|
||
// footprint-comparator-parametrised equivalence | ||
bool geqps(Signature p, Signature q, bool(Footprint,Footprint) cmp)// = p == q; | ||
{ | ||
for (<n,pi> <- p) | ||
{ | ||
bool match = false; | ||
for(<m,xi> <- q, cmp(pi,xi)) | ||
if (match) | ||
return false; // multiple matches! | ||
else | ||
{ | ||
match = true; | ||
q -= <m,xi>; | ||
} | ||
if (!match) | ||
return false; | ||
} | ||
// all matched! | ||
return true; | ||
} | ||
|
||
NameMatch makenamematch(BGFProduction p1, BGFProduction p2) = makenamematch(makesig(p1),makesig(p2)); | ||
NameMatch makenamematch(Signature p, Signature q) | ||
{ | ||
NameMatch nm = {}; | ||
set[str] unmatched = range(q); | ||
for (<a,pi> <- p, <b,xi> <- q, !eqfp(pi,xi)) | ||
{ | ||
nm += <a,b>; | ||
// TODO: should exit if we want to work with non-equivalent signatures. | ||
// But do we, really? | ||
unmatched -= b; | ||
} | ||
// the omega's: | ||
nm += {<"",c> | c <- unmatched}; | ||
return nm; | ||
} |