From 7f60c3d845f3035ce675bfe4cc0d2d01456013c6 Mon Sep 17 00:00:00 2001
From: Vivien Maisonneuve <v.maisonneuve@gmail.com>
Date: Wed, 2 Jul 2014 23:04:15 +0200
Subject: [PATCH 1/1] Implementation of Domain.fromsympy(), tosympy()

---
 pypol/domains.py   | 19 +++++++++++++++++--
 pypol/polyhedra.py | 34 ++++------------------------------
 2 files changed, 21 insertions(+), 32 deletions(-)

diff --git a/pypol/domains.py b/pypol/domains.py
index abc2d91..74351fc 100644
--- a/pypol/domains.py
+++ b/pypol/domains.py
@@ -335,10 +335,25 @@ class Domain:
 
     @classmethod
     def fromsympy(cls, expr):
-        raise NotImplementedError
+        import sympy
+        from .polyhedra import Lt, Le, Eq, Ne, Ge, Gt
+        funcmap = {
+            sympy.And: And, sympy.Or: Or, sympy.Not: Not,
+            sympy.Lt: Lt, sympy.Le: Le,
+            sympy.Eq: Eq, sympy.Ne: Ne,
+            sympy.Ge: Ge, sympy.Gt: Gt,
+        }
+        if expr.func in funcmap:
+            args = [Domain.fromsympy(arg) for arg in expr.args]
+            return funcmap[expr.func](*args)
+        elif isinstance(expr, sympy.Expr):
+            return Expression.fromsympy(expr)
+        raise ValueError('non-domain expression: {!r}'.format(expr))
 
     def tosympy(self):
-        raise NotImplementedError
+        import sympy
+        polyhedra = [polyhedron.tosympy() for polyhedron in polyhedra]
+        return sympy.Or(*polyhedra)
 
 
 def And(*domains):
diff --git a/pypol/polyhedra.py b/pypol/polyhedra.py
index fa2a5c6..6b44bdc 100644
--- a/pypol/polyhedra.py
+++ b/pypol/polyhedra.py
@@ -172,38 +172,12 @@ class Polyhedron(Domain):
             else:
                 return 'And({})'.format(', '.join(strings))
 
-    @classmethod
-    def _fromsympy(cls, expr):
-        import sympy
-        equalities = []
-        inequalities = []
-        if expr.func == sympy.And:
-            for arg in expr.args:
-                arg_eqs, arg_ins = cls._fromsympy(arg)
-                equalities.extend(arg_eqs)
-                inequalities.extend(arg_ins)
-        elif expr.func == sympy.Eq:
-            expr = Expression.fromsympy(expr.args[0] - expr.args[1])
-            equalities.append(expr)
-        else:
-            if expr.func == sympy.Lt:
-                expr = Expression.fromsympy(expr.args[1] - expr.args[0] - 1)
-            elif expr.func == sympy.Le:
-                expr = Expression.fromsympy(expr.args[1] - expr.args[0])
-            elif expr.func == sympy.Ge:
-                expr = Expression.fromsympy(expr.args[0] - expr.args[1])
-            elif expr.func == sympy.Gt:
-                expr = Expression.fromsympy(expr.args[0] - expr.args[1] - 1)
-            else:
-                raise ValueError('non-polyhedral expression: {!r}'.format(expr))
-            inequalities.append(expr)
-        return equalities, inequalities
-
     @classmethod
     def fromsympy(cls, expr):
-        import sympy
-        equalities, inequalities = cls._fromsympy(expr)
-        return cls(equalities, inequalities)
+        domain = Domain.fromsympy(expr)
+        if not isinstance(domain, Polyhedron):
+            raise ValueError('non-polyhedral expression: {!r}'.format(expr))
+        return domain
 
     def tosympy(self):
         import sympy
-- 
2.20.1