ds-kanren 0.2.0.0 → 0.2.0.1

raw patch · 2 files changed

+49/−56 lines, 2 files

Files

• ds-kanren.cabal +2/−55
• src/Language/DSKanren.hs +47/−1

@@ -1,62 +1,9 @@ name:                ds-kanren-version:             0.2.0.0+version:             0.2.0.1 synopsis:            A subset of the miniKanren language description:   ds-kanren is an implementation of the <http://minikanren.org miniKanren> language.-  .-  == What's in ds-kanren?-  .-  ['disconj']-    Try the left and the right and gather solutions that satisfy-    either one.-  ['fresh']-    Create a fresh logical variable-  ['===']-    Equate two terms. This will backtrack if we can't unify-    them in this branch.-  ['run']-    Actually run a logical computation and return results and-    the constraints on them.-  .-  In addition to these core combinators, we also export a few-  supplimentary tools.-  .-  ['=/=']-    The opposite of '===', ensure that the left and right-    never unify.-  .-  == The Classic Example-  .-  We can define the classic @appendo@ relationship by encoding-  lists in the Lisp "bunch-o-pairs" method.-  .-  > appendo :: Term -> Term -> Term -> Predicate-  > appendo l r o =-  >   conde [ program [l === "nil",  o === r]-  >         , manyFresh $ \h t o ->-  >             program [ Pair h t === l-  >                     , appendo t r o-  >                     , Pair h o === o ]]-  .-  Once we have a relationship, we can run it backwards and forwards-  as we can with most logic programs.-  .-  >>> let l = list ["foo", "bar"]-  .-  >>> map fst . runN 1 $ \t -> appendo t l l-  [nil]-  >>> map fst . runN 1 $ \t -> appendo l t l-  [nil]-  >>> map fst . runN 1 $ \t -> appendo l l t-  [(foo, (bar, (foo, (bar, nil))))]-  .-  == Related Links-  .-  Some good places to start learning about miniKanren would be-  .-     * <http://www.amazon.com/The-Reasoned-Schemer-Daniel-Friedman/DP/0262562146 The Reasoned Schemer>-     * <http://www.infoq.com/presentations/miniKanren A presentation at StrangeLoop>-     * <https://github.com/miniKanren/miniKanren The canonical implementation>+ license:             MIT license-file:        LICENSE author:              Danny Gratzer

@@ -1,4 +1,50 @@--- | The toplevel module exports the core language, in+-- | /What's in ds-kanren?/+--+-- ['disconj']+--   Try the left and the right and gather solutions that satisfy+--   either one.+-- ['fresh']+--   Create a fresh logical variable+-- ['===']+--   Equate two terms. This will backtrack if we can't unify+--   them in this branch.+-- ['run']+--   Actually run a logical computation and return results and+--   the constraints on them.+--+-- In addition to these core combinators, we also export a few+-- supplimentary tools.+--+-- ['=/=']+--   The opposite of '===', ensure that the left and right+--   never unify.+--+-- /The Classic Example/+--+-- We can define the classic @appendo@ relationship by encoding+-- lists in the Lisp "bunch-o-pairs" method.+--+-- > appendo :: Term -> Term -> Term -> Predicate+-- > appendo l r o =+-- >   conde [ program [l === "nil",  o === r]+-- >         , manyFresh $ \h t o ->+-- >             program [ Pair h t === l+-- >                     , appendo t r o+-- >                     , Pair h o === o ]]+--+-- Once we have a relationship, we can run it backwards and forwards+-- as we can with most logic programs.+--+-- >>> let l = list ["foo", "bar"]+--+-- >>> map fst . runN 1 $ \t -> appendo t l l+-- [nil]+-- >>> map fst . runN 1 $ \t -> appendo l t l+-- [nil]+-- >>> map fst . runN 1 $ \t -> appendo l l t+-- [(foo, (bar, (foo, (bar, nil))))]+--+-- The toplevel module exports the core language, in -- 'Language.DSKanren.Core' and some simple combinators from -- 'Language.DSKanren.Sugar'. module Language.DSKanren ( module Language.DSKanren.Core