Add Slack bridges

[joaquimg]

Basic implementation finished. Waiting for comments.

[codecov-io]

Codecov Report

Merging #610 into master will increase coverage by 0.08%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #610      +/-   ##
==========================================
+ Coverage    95.2%   95.28%   +0.08%     
==========================================
  Files          48       49       +1     
  Lines        5130     5391     +261     
==========================================
+ Hits         4884     5137     +253     
- Misses        246      254       +8

Impacted Files	Coverage Δ
src/Test/contlinear.jl	100% <ø> (ø)	⬆️
src/Bridges/bridgeoptimizer.jl	99.03% <ø> (+1.92%)	⬆️
src/Bridges/slackbridge.jl	100% <100%> (ø)
src/Utilities/functions.jl	97.59% <100%> (+0.42%)	⬆️
src/Bridges/Bridges.jl	100% <100%> (ø)	⬆️
src/Utilities/mockoptimizer.jl	96.49% <0%> (-0.89%)	⬇️
src/Utilities/cachingoptimizer.jl	90.43% <0%> (-0.3%)	⬇️
src/sets.jl	100% <0%> (ø)	⬆️

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[blegat]

Still not sure about how to test the bridges. Can I create a model with @model that supports ScalarAffineFunction-in-EqualTo but not -in-LessThan?

You can run it through some contlinear tests. The underlying model of the mockoptimizer may support the constraint that is bridged that is not an issue as the SingleBridgeOptimizer bridges all the constraints it can bridge regardless of whether it is supported or not (which is appropriate for testing), as opposed to LazyBridgeOptimizer which is used in JuMP.

operate does not work on vector functions for addition, what should I do?

The missing operate methods should be added

[joaquimg]

PS there is a bunch of indentation mistakes.
VSCode is very annoying, I wanted to have an idea if this is in the right direction and then I will fix style :)

[joaquimg]

It should be almost finished, I might need to fix style and add operate tests

[joaquimg]

There is something about test_delete_bridge.
It assumes no variable was added by the bridge?

[blegat]

There is something about test_delete_bridge.
It assumes no variable was added by the bridge?

You need to implement NumberOfVariables to so that the bridgeoptimizer can adjust the number of variables to ignore the ones created by the bridge. See GeoMeanBridge.

[joaquimg]

It's alive!