Merge pull request #44 from PermutaTriangle/obs-inf

use new obstruction inferral algorithm

Author: ulfarsson

tilescopethree/strategies/inferral_strategies/subobstruction_inferral.py

@@ -1,6 +1,7 @@
 from comb_spec_searcher import InferralRule
 from permuta import Perm
 from tilings import Obstruction, Tiling
+from tilings.algorithms import EmptyCellInferral, SubobstructionInferral
 
 
 def empty_cell_inferral(tiling, **kwargs):
@@ -9,43 +10,12 @@ def empty_cell_inferral(tiling, **kwargs):
     The strategy considers each active but non-positive cell and inserts a
     point requirement. If the resulting tiling is empty, then a point
     obstruction can be added into the cell, i.e. the cell is empty."""
-    active = set(tiling.active_cells)
-    positive = set(tiling.positive_cells)
-    empty_cells = []
-    for cell in active - positive:
-        reqtil = tiling.insert_cell(cell)
-        if reqtil.is_empty():
-            empty_cells.append(cell)
-    newobs = [Obstruction.single_cell(Perm((0,)), cell)
-              for cell in empty_cells]
-    return InferralRule(
-        "The cells {} are empty".format(", ".join(map(str, empty_cells))),
-        Tiling(obstructions=tiling.obstructions + tuple(newobs),
-               requirements=tiling.requirements))
+    eci = EmptyCellInferral(tiling)
+    return eci.rule()
 
 
 def subobstruction_inferral(tiling, **kwargs):
     """Return tiling created by adding all subobstructions which can be
     added."""
-    subobs = set()
-    for ob in tiling.obstructions:
-        subobs.update(ob.all_subperms())
-    newobs = []
-    if subobs:
-        merged_tiling = tiling.merge(remove_empty=False)
-        for ob in sorted(subobs, key=len):
-            if can_add_obstruction(ob, merged_tiling):
-                newobs.append(ob)
-                merged_tiling = Tiling(merged_tiling.obstructions + (ob,),
-                                       merged_tiling.requirements,
-                                       remove_empty=False)
-    if newobs:
-        return InferralRule("Added the obstructions {}.".format(newobs),
-                            Tiling(tiling.obstructions + tuple(newobs),
-                                   tiling.requirements))
-
-
-def can_add_obstruction(obstruction, tiling):
-    """Return true if obstruction can be added to tiling."""
-    return tiling.add_requirement(obstruction.patt,
-                                  obstruction.pos).merge().is_empty()
+    soi = SubobstructionInferral(tiling)
+    return soi.rule()