Decompose Global (cpmpy.transformations.decompose_global)
Decompose any global constraint not supported by the solver.
- cpmpy.transformations.decompose_global.decompose_global(lst_of_expr, supported={}, supported_reif={})[source]
- cpmpy.transformations.decompose_global.decompose_in_tree(lst_of_expr, supported={}, supported_reified={}, _toplevel=None, nested=False)[source]
Decomposes any global constraint not supported by the solver Accepts a list of CPMpy expressions as input and returns a list of CPMpy expressions,
if nested is True, new constraints will have been added to the _toplevel list too
supported: a set of supported global constraints or global functions
supported_reified: a set of supported reified global constraints (globals with Boolean return type only)
toplevel: a list of constraints that should be added toplevel, carried as pass by reference to recursive calls
- Special care taken for unsupported global constraints in reified contexts and for numeric global constraints
in a comparison.
- Supported numerical global functions remain in the expression tree as is. They can be rewritten using
cpmpy.transformations.reification.reify_rewrite The following bv -> NumExpr <comp> Var/Const can be rewritten as [bv -> IV0 <comp> Var/Const, NumExpr == IV0]. So even if numerical constraints are not supported in reified context, we can rewrite them to non-reified versions if they are total.