Overload BoneMarketModel.NewIntermediateIntVar

Intermediate integer variables can now be created for compatible partial
methods, which massively increases the expressiveness of each helper
function.

This change should allow the compound helper functions, such as
AddDivisionMultiplicationEquality, to be removed entirely. It will also
allow even the most complex buyers to avoid intermediate variables.
This commit is contained in:
Jeremy Saklad 2021-10-16 13:04:31 -05:00
parent fd8abb7501
commit 6b9643041a
Signed by: Jeremy Saklad
GPG Key ID: 9CA2149583EDBF84
1 changed files with 12 additions and 4 deletions

View File

@ -1,6 +1,6 @@
__author__ = "Jeremy Saklad"
from functools import cache, partialmethod, reduce, singledispatch
from functools import cache, partialmethod, reduce, singledispatch, singledispatchmethod
from ortools.sat.python import cp_model
@ -126,11 +126,19 @@ Each parameter is interpreted as a BoundedLinearExpression, and a layer of indir
self.AddLinearExpressionInDomain(linear_exp, domain.Complement()).OnlyEnforceIf(intermediate.Not())
return intermediate
def NewIntermediateIntVar(self, linear_exp, name, *, lb = cp_model.INT32_MIN, ub = cp_model.INT32_MAX):
"""Creates an integer variable equivalent to the given expression and returns a tuple consisting of the variable and constraint for use with enforcement literals."""
@singledispatchmethod
def NewIntermediateIntVar(self, expression: cp_model.LinearExpr, name, *, lb = cp_model.INT32_MIN, ub = cp_model.INT32_MAX):
"""Creates an integer variable equivalent to the given expression and returns a tuple consisting of the variable and constraint for use with enforcement literals.
`equality` must be either a LinearExp or a unary partialmethod that accepts a target integer variable and returns Constraints."""
intermediate = super().NewIntVar(lb, ub, name)
return (intermediate, self.Add(intermediate == linear_exp))
return (intermediate, self.Add(intermediate == expression))
@NewIntermediateIntVar.register
def _(self, expression: partialmethod, name, *, lb = cp_model.INT32_MIN, ub = cp_model.INT32_MAX):
intermediate = super().NewIntVar(lb, ub, name)
return (intermediate, expression.__get__(self)(intermediate))
def NewIntVar(self, name, *, lb = cp_model.INT32_MIN, ub = cp_model.INT32_MAX):
return super().NewIntVar(lb, ub, name)